Projects

Abstract

Three-dimensional electron diffraction (3DED) has revolutionized the study of crystalline materials, allowing researchers to solve crystal structures from nanometer sized crystals. Traditionally, 3DED experiments are conducted under high-vacuum conditions, where samples are isolated from environmental factors, enabling precise analysis of stable structures. However, such an approach often falls short when it comes to capturing dynamic processes, transient states, or reactions that occur under realistic operating conditions. This gap has driven the development of in situ 3DED techniques, where materials are studied in their native or reactive environments, providing valuable insights into structure-property relations under real-world conditions. In this project, the possibility is explored of acquiring in situ 3D ED data during electrocatalytic reactions. The perovskite-based Ba0.5Sr0.5Co0.8Fe0.2O3-x is chosen for these pioneering explorations due to its outstanding activity for the oxygen evolution reaction (OER) in alkaline solutions. The transformation of this material during the OER process is still under discussion, with several suggestions in literature but none proven. In-situ 3D ED is the perfect technique to unravel the nanoscale structural changes in this material, catalyzing a further improvement of the properties of the material as an electrocatalyst.

Researcher(s)

• Promoter: Hadermann Joke
• Fellow: Hajizadeh Amirhossein

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Quantum dots (QDs) exemplify the successful transfer of innovative nanomaterials from a lab-scale invention to a technology that offers better and more power-efficient electronic devices, or makes buildings generate renewable energy. Such implementations, however, keep QDs under permanent loading, such as constant illumination, elevated temperature or exposure to environmental agents. Efforts to make QDs resilient against loading-induced ageing and loss of performance are time-consuming and costly. Track The Twin addresses this problem through a research and training program aimed at creating and using QD digital twins (QDDTs). Focused on the case of QDs under illumination, this goal creates an exceptionally rich environment to form a new cohort of early-stage researchers (ESRs) in nanomaterials. Trained as experts in the latest methods of synthesis, structure analysis and time-resolved spectroscopy – from infrared to x-ray - and computational materials science, ESRs will learn to join forces to reach the common goal of demonstrating loading-resilient QDs synthesized according to best QD structures as predicted by the QDDTs. To facilitate such a collaborative endeavor, all ESRs will be trained to use and co-develop a common data platform and they will be permanently exposed to the diversity of environments needed to implement together a QDDT. Thanks to the deep collaboration between word-leading academic beneficiaries and start-up companies in nanomaterials and computational chemistry, scientific training is complemented by extensive transferrable skills training. Moreover, the timeliness of the research and training topic – digital twins in materials science - enables the consortium to implement a proactive outreach strategy, which extends from a personal outreach activities of the ESRs to QD technology broadcasting to reach a broader field of industrial actors and policy makers and ensure the network has lasting impact on nanomaterials research and innovation.

Researcher(s)

• Promoter: Bals Sara
• Co-promoter: Van Aert Sandra

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The principal type of nuclear fuel is uranium dioxide (UO2). After discharge from a nuclear reactor the spent fuel is highly radioactive and emitting a considerable amount of heat, which necessitates an intermediate storage period of several years before any further handling can take place. Ultimately, safe disposal needs to be applied to manage the spent fuel in a sustainable way. Direct disposal in stable geological repositories is being considered by many countries. However, in most countries, no political decision has yet been made, leading to prolonged intermediate storage periods up to several decades. Also during this intermediate storage period, safety must be ensured, and for any technical solution, incidental or accidental exposure of the spent nuclear fuel to oxidizing atmospheres is part of the safety assessments. Hence, a good understanding on radiological consequences of oxidative reactions of irradiated UO2 is important. The response of conventional nuclear fuel to oxidation and corrosion is determined mainly by the physico-chemical properties of uranium. UO2 is quite susceptible to oxidation, already at room temperature, and under normal atmospheric conditions it tends to evolve towards the thermodynamically more stable oxide U3O8. This transformation is associated with a considerable reorganization of the crystal structure, and results in a volume expansion of about 36% which is detrimental for the integrity of confinement barriers like the fuel cladding or storage containers. Research efforts in this domain have been numerous, because a confinement rupture may expose environmentally critical elements to the biosphere. Research on formation and stability of different binary oxides in heavier actinide systems is equally important, but these oxide systems are not yet characterized to the same extent as that of uranium. This is in part due to their radioactive nature, which makes handling considerably more complicated, and also because of the limited availability of materials in a sufficiently pure form. Transuranium elements are currently under investigation at SCK CEN in the context of optimal spent fuel management, but also for unconventional applications such as "nuclear batteries" for deep space exploration (e.g. the Np-O system), or in niche applications such as actinide-based fission dosimeters. Their handling typically involves liquid-to-solid conversion processes to obtain oxide precursors or final products, and hence, understanding their redox chemistry is of vital importance. In this PhD project proposal the redox behavior of selected actinides U and Np will be investigated, with the aim to increase our understanding of their binary oxides. The research will focus specifically on the characterization of solid-state transformations and structural relations at the nanoscale between, influenced by external conditions such as temperature, oxygen partial pressure and moisture content. Solid state sample preparation routes as well as more advanced liquid-to- solid conversion routes based on sol-gel chemistry will be used to produce chemically homogeneous materials. In-situ thermogravimetry, calorimetry and X-ray diffraction will be applied to monitor the response to dry and humid gaseous environments (oxidizing, anoxic, reducing, and combinations thereof) at the macroscale. Microscopic observations using scanning and transmission electron microscopy will allow to distinguish features at the micro- and nanoscale, respectively. To unravel the compositional and structural relations occurring between the oxide phases, spectroscopic techniques such as X-ray absorption spectroscopy (XAS), as well as more advanced diffraction techniques like selected- area electron diffraction and neutron diffraction will be considered.

Researcher(s)

• Promoter: Lamoen Dirk

Research team(s)

• Electron microscopy for materials research (EMAT)

Project website

Project type(s)

• Research Project

Abstract

Metal halide perovskites (MHPs) are highly promising semiconductors for novel optoelectronic devices. A timely goal is to extend the use of MHPs to chiroptoelectronic applications, such as circularly polarized light photodetectors. Due to the flexibility of arranging the organic and inorganic building blocks in perovskites, it recently became possible to synthesize chiral perovskites with a non-centrosymmetric crystal structure. In my project I will focus on MHP nanocrystals (NCs) containing chiral cations and MHP NCs assembled in a three-dimensional chiral morphology. For both systems, the chirality transfer mechanisms are not yet understood. Therefore, the aim of my project is to exploit advanced transmission electron microscopy (TEM), including 4D scanning TEM, electron tomography and electron diffraction to quantify the helicity of self-assembled structures and the occurring distortions of the inorganic framework in MHPs with chiral cations. Due to the high beam sensitivity of MHPs and organic cations the development of novel low-dose techniques will be crucial. The insights on chiral MHPs, obtained from this project will pave the way to design novel chiroptical devices.

Researcher(s)

• Promoter: Bals Sara
• Fellow: Schrenker Nadine

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Proton exchange membrane fuel cells (PEMFCs) are poised to enable a decarbonized heavy-duty mobility, but progress towards lower platinum requirements remains needed. The optimization of the high surface area, nanoporous, carbons that supports the Pt nanoparticles in the cells is a particularly promising pathway to achieve high Pt utilization and efficiency. Yet, characterizing, simulating, and therefore manipulating these carbons has proven difficult due to their three-dimensional (3D), nanoscopic, and highly heterogeneous nature. In this project, I will use advanced electron microscopy methods for 3D and in situ characterization and link them with atomistic simulations in order to uncover the multiscale porous structure the carbon supports from the atomic to the primary particle level. Specifically, I will reveal i) the atomic structure of the pores in carbon supports, ii) the morphological descriptors or the pore network and their relationships to transport resistances, and iii) the structural changes that improve PEMFC performance. The results will provide insights into the origins of performance losses, deliver novel knowledge and datasets for enhanced accuracy in modeling, and therefore contribute towards high-power, low-Pt, PEMFCs. This project will further benefit the other applications of porous carbons, including heterogeneous catalysis, batteries and supercapacitors, and provide innovative methods to characterize the next generation of carbon and energy materials.

Researcher(s)

• Promoter: Bals Sara
• Fellow: Girod Robin

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Nanomaterials already have become indispensable in numerous modern technologies that impact our society. It recently became clear that their coupling with light holds significant promise for innovative developments that may open the route to novel light-driven applications in energy storage, photoelectrochemical sensing, photovoltaics, photocatalysis, drug delivery, and more. Incorporation in actual applications will, however, strongly depend on a deep understanding of the factors that influence the structure-property connection, an improved stability as well as on their technoeconomic and environmental performance. To tackle these crucial challenges, the Nano-Light consortium emerges as a unique and multidisciplinary platform. The consortium brings together extensive expertise in nanoscience covering the synthesis of photoactive nanostructures, advanced electron microscopy and X-ray characterisation, computational materials science, applied nanoengineering and techno-sustainability assessments. By combining cutting-edge (3D) transmission electron microscopy with advanced light sources and environmental holders, the consortium aims to optimize the interaction between nanomaterials and light under working conditions. Such experiments are extremely challenging, but if successful, they will yield unprecedented insights into the fundamental mechanisms governing light-matter interactions at the nanoscale. By exploiting a synergistic approach, one of the primary objectives of the consortium is to obtain comprehensive understanding on how nanomaterials absorb, scatter, emit, or manipulate light, thereby providing crucial knowledge for the design and optimization of next-generation technologies. Such understanding will be crucial for applications in which light plays a beneficial enabling role or, conversely, in scenarios where light accelerates the degradation of the behaviour of the nanomaterials. These areas include the plasmonic chiroptic nanoparticles for early disease detection, overcoming light degradation of pigments in art conservation or (perovskite) photovoltaic nanomaterials for solar cells or X-ray detectors, plasmon-enabled biosensing and light–driven drug delivery in nano-medicine applications, photo(-electro)catalytic hydrogen production or CO2 conversion. Furthermore, the consortium will develop techno-economic and environmental assessments at early technology readiness levels for the envisioned nanotechnological applications to promote safe and sustainable technological solutions. These goals of Nano-Light are in excellent agreement with the sustainable research and innovation goals put forward by the EU. As such, the research conducted under the Nano-Light consortium will strengthen the position of UAntwerp on the European map as an established nanoscience centre leading to further collaborations in the field of nanotechnology and related technologies.

Researcher(s)

• Promoter: Bals Sara
• Co-promoter: De Wael Karolien
• Co-promoter: Janssens Koen
• Co-promoter: Milosevic Milorad
• Co-promoter: Van Aert Sandra
• Co-promoter: Van Passel Steven
• Co-promoter: Verbruggen Sammy

Research team(s)

• Electron microscopy for materials research (EMAT)

Project website

Project type(s)

• Research Project

Abstract

Electron microscopy is a powerful tool for characterizing nanomaterials at the atomic scale. However, small nanoclusters are particularly susceptible to electron beam activation due to their high surface-to-volume ratio and sensitivity to energetic electrons1. The interaction between the electron beam and nanoclusters can induce mobility and structural changes2, compromising the accuracy of dynamic in situ studies. Here, we aim to quantitatively analyze the electron beam-induced restructuring of small nanoclusters and develop strategies to mitigate this effect by investigating different experimental parameters such as beam energy, sample environment, and low-dose imaging techniques. Implementing these advanced imaging and analysis techniques will help us understand the electron beam effect on the clusters and study their dynamics under controlled in situ conditions. In addition, we propose to delve deeper into the behavior of nanoparticles on solid surfaces under applied electric fields through in situ biasing experiments. Understanding how nanoparticles respond to electric fields on a solid substrate is crucial for various applications, including catalysis, sensing, and nanoelectronics3. By applying controlled electric fields during electron microscopy imaging, we can explore the dynamics of nanoparticle assembly and reconfiguration under external stimuli. Furthermore, to facilitate comprehensive 3D investigations of these assemblies, we plan to develop a novel tomography biasing chip that enables us to probe the three-dimensional architecture of nanoparticle assemblies in real-time, providing valuable insights into their structural evolution and response to external stimuli.

Researcher(s)

• Promoter: Bals Sara
• Fellow: Balalta Deema

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Scanning Transmission Electron Microscopy (STEM) Energy Dispersive X-ray (EDX) analysis were done successfully by an EMAT operator on the Osiris TEM under supervision of a TEM operator of UGent duing one day.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Metal nanoparticles with asymmetric morphologies have gained increasing scientific interest, because of the possibility to tune their interaction with (polarized) light. Hereby, the optical activity is closely related to the three-dimensional shape of the nanomaterial. However, quantifying morphological features of nano-objects is extremely challenging. Electron tomography enables one to retrieve the three-dimensional morphology of nanomaterials, so far but only a qualitative analysis of the morphology of nanoparticles was made. A method to quantify the helicity of complex nanomaterials at the single particle level starting from high-quality electron tomography reconstructions was recently proposed. However, in order to provide significant insights into the fundamental origin of optical properties, new techniques for high throughput three-dimensional data acquisition are required. This project seeks to develop such approaches, based on the flexibility of modern aberration corrected transmission electron microscopes in combination with advanced computational techniques.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Future technological innovations in areas such as the Internet of things and wearable electronics require cheap, easily deformable and reasonably performing printed electronic circuitries. However, current state-of-the-art (SoA) printed electronic devices show mobilities of ~10 cm2/Vs, about ×100 lower than traditional Si-electronics. A promising solution to print devices from 2D semiconducting nanosheets gives relatively low mobilities (~0.1 cm2/Vs) due to the rate-limiting nature of charge transfer (CT) across inter-nanosheet junctions. By minimising the junction resistance RJ, the mobility of printed devices could match that of individual nanosheets, i.e., up to 1000 cm2/Vs for phosphorene, competing with Si. HYPERSONIC is a high-risk, high-gain interdisciplinary project exploiting new chemical and physical approaches to minimise RJ in printed nanosheet networks, leading to ultra-cheap printed devices with a performance ×10–100 beyond the SoA. The chemical approach relies on chemical crosslinking of nanosheets with (semi)conducting molecules to boost inter-nanosheet CT. The physical approach involves synthesising high-aspect-ratio nanosheets, leading to low bending rigidity and increased inter-nanosheet interactions, yielding conformal, large-area junctions of >10e4 nm2 to dramatically reduce RJ. Our radical new technology will use a range of n- or p-type nanosheets to achieve printed networks with mobilities of up to 1000 cm2/Vs. A comprehensive electrical characterisation of all nanosheet networks will allow us to not only identify those with ultra-high mobility but also to fully control the relation between basic physics/chemistry and network mobility. We will demonstrate the utility of our technology by using our best-performing networks as complementary field-effect devices in next- generation, integrated, wearable sensor arrays. Printed digital and analog circuits will read and amplify sensor signals, demonstrating a potential commercialisable application.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Using Focused Ion Beam Scanning Electron Microscopy ten electron transparent lamellas for Transmission Electron Microscopy of targeted regions of interest are prepared of different materials on request.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Research in the fields of nanoscience and nanotechnology is vital for sustainability globally: advancement in nanoscience and nanotechnology cannot be achieved without using research infrastructures (RI). RIANA encompasses 7 European networks of top-level RIs to cover the most advanced techniques relevant for synthesis, nanofabrication, processing, characterization, analytics, as well as simulation capacity. Highly customised and efficient access to 69 infrastructures is coordinated via a single-entry point and enabled through comprehensive Science and Innovation Service by senior scientists, experts for the transfer of technology from academia to industry, and highly trained Junior Scientists. The Junior Scientist boost RI experience to an entirely new level: they provide customised Science Service supporting users from initial ideas to hands-on experiments, data analysis and dissemination of results to generate the greatest impact from access to world-class RI. This core of RIANA is aligned to attract experienced and new users from academia or industry making their promising ideas a success and push them to higher TRL. RIANA is flexible to upcoming emergent scientific topics and needs: together with stakeholders from the nanocommunity, RIANA implements the opportunity to offer flexible access to additional infrastructures in, and even outside of Europe beyond the current consortium, and to direct the Science Service towards evolving user needs via additional specialised Junior Scientists. Based on the four years of experience, the RIANA consortium will develop a roadmap for the future of the nanoscience and nanotechnology at European RIs.

Researcher(s)

• Promoter: Verbeeck Johan
• Co-promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

DELIGHT aims at excellence of Europe in nanoscience and impact in research and development at the highest level. The project focuses on multifunctional nanomaterials based on colloidal particles, organic/inorganic perovskites, and organic and biomaterials. Design and fabrication of these materials for state-of-the-art applications requires a high level of interdisciplinarity with expertise from chemistry, physics, material science, engineering, nanofabrication and biology, combined with the most advanced spectroscopy tools. The scientific objectives of DELIGHT are to establish a platform of highly versatile functional nanomaterials, with the use of machine learning and artificial intelligence for material/device development and characterization. The focus is on multifunctional hybrids, heterostructures, and assemblies, and to fully exploit their potential for catalysis, energy, lighting, plasmonics, and theranostics. The research is organized in 3 work packages (WPs) that target nanomaterial development, functional composites and in-depth characterization, and device applications. Social and training objectives are the education of young researchers in Europe on the highest level, with emphasis on interdisciplinarity that is fundamental in modern nanoscience, the advancement of technological know-how that enables a sustainable and eco-friendly modern society, and promotion of gender equality in the scientific landscape at all levels. These goals are implemented in a WP dedicated to training, organizing lectures, workshops, technology transfer, and outreach and dissemination events. DELIGHT assembled an academic team of outstanding excellence, which links key players in the EU working on state-of-the-art nanomaterials with world leading universities in the US, Canada, and Argentina that are known for their unique scientific and technological capabilities and efficient technology transfer.

Researcher(s)

• Promoter: Bals Sara
• Co-promoter: Covaci Lucian
• Co-promoter: Milosevic Milorad
• Co-promoter: Van Aert Sandra
• Co-promoter: Verbruggen Sammy

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Electron tomography is an invaluable tool for characterizing the 3D structure of nanomaterials. Recently, there has been significant progress towards the real-time and fast approaches for determining 3D morphology of nanoparticles. These include quasi-3D imaging [1] morphology imaging with secondary electron beam induced current (SEEBIC)[2] and fast tomography.[3] However, these techniques on their own are insufficient for bulk analysis of material properties or characterization of samples with structures that alter rapidly such as beam sensitive MOFs and perovskites. Herein we wish to investigate the use of these techniques in combination with computational techniques such as real-time neural radiance fields (NERFs), and machine learning[4] to perform real-time analysis of time sensitive nanomaterials. One such avenue would be to utilize fast tomography with NERFs to extract quickly extract a 3D scene which can be converted to a 3D volume for further analysis or to use machine learning with Fourier domain filters and multiprocessing to obtain real-time low resolution reconstructions for analysis while computing higher resolution reconstructions.

Researcher(s)

• Promoter: Bals Sara
• Fellow: Craig Tim

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The overarching goal of the project is to develop an in-line material-monitoring setup in a production line using recycled materials as raw materials. In order to develop an in-line material-monitoring setup based on machine learning, the training data should contain a wide range of data related to specific material characteristics such as composition, crystal phase, size and shape. Electron microscopy can provide this information on the micro- to nanometre scale and will serve as ground truth data for machine learning approaches. For every subset of data, there is a specific microscope setup, detector and processing methodology involved. Using electron microscopes, the information is inherently coming from a very local area of the material, on the micro- to nanometre scale, and it is therefore a challenge to do high-throughput analyses. The aim of the project is to initiate the development of high-throughput methods for multiscale and multimode characterization of recycled materials. Depending on the recycled materials and their envisioned usage in future products, different descriptors will be relevant. For example, descriptions with various levels of accuracy of crystallinity, composition, or morphology at different scales would be differently relevant for e.g. recycled battery materials or concrete. In recycled cathode materials, the crystallinity of the oxide matrix and the nature of contaminating coatings will greatly influence the performance. Alternatively, the properties of recycled concrete materials will greatly depend on the porosity, morphology and texture at the micro and nanoscale.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Metal halide perovskites (MHPs) are promising for light emitting diodes (LEDs) due to their high color purity, band gap tunability and low cost of fabrication. However, their actual commercial use in LEDs is hindered by insufficient external quantum efficiency and instability to external triggers including heating, moisture and oxygen. I will therefore develop well-organized self-assemblies of MHP nanocrystals, for which the stability is expected to be majorly improved, due to the close packing and the doping of individual nanocrystals. In addition, the collective properties of the assemblies are envisaged to result in enhanced efficiency. Consequently, highly uniform, optically active and stable active layers for LEDs will be obtained. The synthesis and assembly will be guided by iterative measurements of the optical properties together with a detailed characterization by quantitative transmission electron microscopy (TEM). 3D characterization will allow me to extract quantitative descriptors to evaluate the packing of the nanocrystals, whereas in situ TEM studies will enable me to understand the degradation behavior so that my project will open the route to the incorporation of assemblies of MHP nanocrystals in the next generation of LEDs. I therefore aim at proving the use of self-assembled MHPs for LEDs in an experimental proof-of-concept (TRL 3) up to a technology validated in the laboratory (TRL 4).

Researcher(s)

• Promoter: Bals Sara
• Fellow: Skvortsova Irina

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

By means of Focused Ion Beam Scanning Electron Microscopy (FIB-SEM) thin electron transparent lammela's are being prepared that can be studied by High-Resolution Transmission Electron Microscopy (HR-TEM).

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Transmission electron microscopy (TEM) is a powerful technique to fully characterise the local structure of a broad range of materials. Due to many recent hardware advances, the quality of TEM measurements is nowadays ultimately determined by the sample supports. Surprisingly though, their importance has been majorly overlooked so far. The many benefits of graphene layers as a support have been well-recognised by the community, but commercial "graphene grids" show poor coverage and are dominated by unwanted residues and Cu nanoparticles from the preparation process. Consequently, commercial graphene grids currently correspond to merely 1% of the grids used. A solution to this problem is a novel protocol to produce high-quality graphene grids, developed within my ongoing ERC Consolidator grant "REALNANO". A head-to-head comparison with the state-of-the-art demonstrates the superior quality of the HYPERGRAPH grids. Moreover, our ongoing market survey with leading groups in both materials and life science indicates a very strong need for graphene gridsthat yield high and constant quality. Therefore, the overall aim of this PoC isto deliver our HYPERGRAPH supports to the TEM community, our beachhead market. To reach this goal, our methodology is based on further product development (reproducibility, cost-efficiency and shelf-life), exploration of other possible applications and business planning. In this manner, we aim to increase the Technology Readiness Level for HYPERGRAPH from 4 to 7 and the and Commercial Readiness Level from 4 to 6. Feeling the "pain" related to the poor quality of TEM supports as an end user every day, I am convinced that valorisation of our technology can fill a crucial void in the TEM value chain. In this manner, HYPERGRAPH will enable characterisation and further development of new generations of nano- and biomaterials, with applications in fields as broad as catalysis, medicine, protein research, viral infections and energy.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Graphene and related materials have high potential to be incorporated in a variety of devices because of their high electric and thermal conductivity. However, actual use in real applications demands a thorough understanding of the connection between the physical properties and deviations from the ideal structure. To gain such understanding, a local characterization, by electron microscopy is required. Unfortunately, graphene and multilayers hereof are very sensitive to the electron beam. Therefore, we will exploit novel developments in the field to apply low-dose electron microscopy techniques. The limits of these techniques will be explored, which will be of importance for several ongoing collaborations and future Horizon Europe project applications.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

IMPRESS (Interoperable electron Microscopy Platform for advanced RESearch and Services) aims to co-develop and deliver advanced transmission electron microscopy (TEM) instrumentation, methods and tools that will revolutionize the way in which TEMs are used by all new and well-established scientific communities, integrate them with other instrumentation at analytical research infrastructures (RIs) and create new business opportunities for small and medium-sized enterprises. The core of the project is the development of a standardized cartridge-based interoperable platform for TEM that is based on common interfaces and data formats, is flexible and adaptable and allows users to perform advanced correlative experiments using different instruments and to co-develop methodological options that are not yet satisfied by commercially available electron microscopes. The solutions will be delivered at technology readiness level 8 through a pre commercial procurement. The project also involves the co-development of new electron sources, techniques based on adaptive optics and event-driven detectors, application-relevant in situ/operando sample environments and software for simulation of experiments and remote access based on artificial intelligence. By the end of the project, these developments will be integrated with the new cartridge based platform, in order to make them available to all users of RIs and other TEMs owners. An open knowledge and innovation hub for TEM will be created and a training programme will promote the new solution, to initiate RI staff in their use and to provide both materials and life science communities with optimized tools for tackling societal challenges, especially in the energy and health sectors. The project will exploit synergies and collaboration with five RIs of European dimension for the benefit of users from diverse scientific communities and will pave the way towards a new cooperative model for the development and operation of RIs for TEM

Researcher(s)

• Promoter: Verbeeck Johan

Research team(s)

• Electron microscopy for materials research (EMAT)

Project website

Project type(s)

• Research Project

Abstract

Metal halide nanocrystals (NCs) have emerged as attractive materials for applications such as displays, solar cells and medical scanners. Even though their potential impact on society is huge, commercialization is hampered by the presence of lead and the instability of the materials against e.g. heat, moisture or light. To develop novel (lead-free) NCs with optimized properties and stability, characterization of the atomic structure and composition is crucial. Transmission electron microscopy (TEM) is an ideal tool, but imaging metal halide NCs by TEM is extremely difficult because of their sensitivity to the electron beam. The project is a unique collaboration between EMAT, the electron microscopy group at the University of Antwerp, and the group of Professor Liberato Manna at IIT (Genova). The main goal is to develop innovative TEM methods that will enable us to link the structure and composition of metal halide NCs to their properties and stability. We will hereby exploit the information richness and dose efficiency of a novel technique, called 4D scanning TEM (STEM), and will identify e.g. strain, defects and new phases in metal halide NCs. Moreover, 4D STEM will be combined with in situ TEM holders, which will enable us to investigate atomistic phenomena that occur as a result of environmental triggers. We envisage that our project will lead to the preparation of new generations of NCs with improved properties and stability.

Researcher(s)

• Promoter: Bals Sara
• Co-promoter: Van Aert Sandra

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The project will build upon recent work regarding the development of graphene grids for TEM, supported by new transfer techniques. The availability of graphene grids within EMAT has enabled a series of experiments that were previously not possible due to a lack of necessary TEM support. This gives us the opportunity to explore the potential of using graphene grids for the characterization of the proposed materials. The results of this project are important for users from several domains, such as materials science, life science, or in situ electron microscopy. In terms of licensing opportunities, this research is relevant for three main groups of candidate companies: the current suppliers of TEM graphene grids, manufacturers of in situ TEM holders, and a group of companies that have recently become active in the cryoTEM market focusing on Single Particle Analysis.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

DYNASTY's primary objective is to build in the European South East, and in particular in the Foundation for Research and Technology Hellas (FORTH) in Crete, a significant pole of attraction for nanomaterials researchers and scientists. This will be accomplished through joint research activities and partnering with two well-established European research teams, which are in the forefront of nanomaterials research. The activities will contribute in scientific production that will motivate and attract young scientists in nanomaterials (e.g. 2D materials) science and technology. The partners include: (a) the University of Antwerp (UA) with strong expertise in advanced Electron Microscopy for Materials Science and in Condensed Matter Theory (the EMAT and CMT groups, respectively), which are both part of the UA NANOlab Center of Excellence (Belgium) (b) and the National Institute of Applied Sciences (INSA- University of Toulouse), with deep expertise in advanced spectroscopic characterization techniques of 2D materials. The activities involve training through cross-lab visits, workshops, short courses, joint conferences, and well-designed communication activities to attract young scientists at FORTH. All teams will provide their expertise and collaborate to build advanced Imaging and Spectroscopy expertise at FORTH (combining non-linear and time-resolved optical spectroscopies) that will provide precise fine structural analysis of 2D materials and their heterostructures. By the end of the three-year project, FORTH will gain advanced skills in nanomaterials characterization and knowhow in nanoelectronic devices fabrication. As a result, DYNASTY will create a collaborative platform for widening experimental networks among nanomaterials labs in Europe, enabling local teams to produce excellent interdisciplinary nanoscience, currently lacking in Greece.

Researcher(s)

• Promoter: Verbeeck Johan
• Co-promoter: Bals Sara
• Co-promoter: Covaci Lucian
• Co-promoter: Milosevic Milorad

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The salinity gradients that occur where fresh water flows into salty ocean water represent a very large and almost completely untapped source of clean, so called blue energy, based on osmosis. One reason blue energy remains untapped is the inefficiency of current methods to harvest it, mostly due to the poor performance of the membrane processes being used. A promising potential solution to this problem is to use atomically thin 2D materials with nanopores in them as the membranes. Proof of principle experiments with nanopores in 2D materials have demonstrated osmotic power densities up to six orders of magnitude better than conventional membranes. Charge buildup around the nanopores creates a filter that allows salt ions with only one sign of charge to be driven by the chemical potential gradient from a salty reservoir through the pores and into a fresh water reservoir. Much like in a battery, the resulting segregated charge build up creates an electrical potential difference that can be used for electrical power. However, in order to enable maximum efficiency power generation from blue energy, a better understanding of the nanopores is needed. At present even basic knowledge such as their atomic structures remains lacking. In this project we will determine the atomic structure of nanopores which have been characterised for blue energy performance and develop methods of probing the charge density and electric fields at and around the nanopores with electron microscopy. In conjunction with first principles theory we will use the correlations between blue energy performance and the findings of the microscopy experiments to understand the physics of osmotic power production with nanopores in different 2D materials. We will thus uncover what makes the best nanopore based membranes, facilitating the engineering of nanopores with optimal blue energy performance.

Researcher(s)

• Promoter: Pennycook Timothy
• Fellow: Chennit Tamazouzt

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The project is focused on the microstructural analysis of so-called "in-vessel" materials for ITER and future fusion reactors and which will be exposed to heavy operational conditions including high heat loads and fast particle irradiation damage. At Belgian Nuclear Research Centre we mimic the irradiation conditions and investigate the material response as well as subsequent change of properties. Following ITER needs and the European Fusion Roadmap the investigation will focus on main in-vessel materials such as tungsten (W), Eurofer97 steel and copper alloys. The scientific/technical objective of this project is to build a comprehensive set of microstructural data to be obtained by transmission electron microscopy and specially designed tools allowing to perform in-situ investigation under applied thermal or mechanical loads. Thereby obtained microstructural information is of fundamental importance to rationalize the change of material properties under irradiation as well as it serves as a backbone for the validation of the available computational models dealing with predicting the microstructural state under fusion operational conditions. The project is scheduled for 4 years, it will include a number of international secondments to ITER partners and other fusion labs to perform experiments on unique equipment outside of EU.

Researcher(s)

• Promoter: Schryvers Nick

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The main goal of TEMPEL is to develop a new electrolyser that will be able to produce hydrogen from steam and low temperature waste heat. EMAT will characterise the newly developed materials using SEM and TEM.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The main purpose of the CLUE-innovationproject is the development of an efficient electrolyzer for longterm electrochemical conversion of CO2 to ethylene under realistic and industry relevant CO2 streams and using efficient electrodes based on mono- and bimetallic clusters.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

CHISUB features a multidisciplinary approach, towards crystallization mechanisms of molecules, which uses chiral symmetry breaking as local probe of ordering phenomena and as a tool for enantiomeric separation. Crystallization often starts on surfaces of rigid substrates with the formation of 2D self-assembled molecular layers and then extends to bulk phases. CHISUB intends to design, synthesize, and characterize a library of molecular systems tailored to break chiral symmetry at different time- and length-scales. These systems will be studied by scanning probe microscopy at 2D and by electron microscopy and diffraction techniques when extending to 3D. Chiral symmetry breaking towards specific handedness will be directed by external stimuli, such as a combination of electric and magnetic fields, spin polarization, and even rotation of molecular machines. Theoretical and experimental studies will be carried out in synergy to explore ordering phenomena and chiral selectivity processes from first principles and reach a fundamental understanding beyond specific systems.

Researcher(s)

• Promoter: Van Aert Sandra
• Co-promoter: Altantzis Thomas

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Defects such as dopants, vacancies and grain boundaries can dramatically alter the properties of 2D materials. Likewise new physical phenomena often emerge from interfaces between different materials. With 2D materials systems such interfaces can be laterally connected or stacked vertically, and exciting unexpected behaviors are emerging from both classes of interfaces. Understanding such systems requires knowledge of their local microscopic structure and composition. Electron ptychography and 4D STEM in general have recently experienced a renaissance as researchers realize the power of 4D STEM to provide local microscopic information that could not be directly accessed before. However 4D STEM, including ptychography, have previously been limited by the speed at which pixelated detectors could capture the required images, severely curtailing the speed at which 4D STEM could be performed. In this project we will overcome this limitation with our new 4D STEM detector which can operate hundreds of times faster than previous pixelated detectors. Using this breakthrough in speed we will develop superior means of not only imaging structure, but also atomic scale charge and field mapping, and extend such analysis into the third spatial dimension by combining 4D STEM with tomography and optical sectioning. Armed with these new tools we will enable a greater understanding of 2D material systems.

Researcher(s)

• Promoter: Pennycook Timothy

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Metal-organic frameworks (MOFs) are porous crystalline materials with tailorable chemistry. Their excellent properties are of interest for energy storage devices, gas adsorption and separation, catalysis, drug delivery, and many others. However, there are still many open fundamental questions about their nature and interactions with the surroundings, which could only be answered with in situ transmission electron microscopy (TEM) at the atomic scale. Unfortunately, due to their sensitivity to the electron beam, such studies are highly challenging or even impossible when 3-dimensional (3D) imaging is required. Here, I envision the combination of advanced TEM and dedicated 3D reconstruction algorithms as a groundbreaking new approach to reliably characterize the 3D structure of MOFs under realistic conditions. Visualizing the framework structure of MOFs, including defects and interfaces at high temperature and in a gas is extremely challenging, but will lead to a wealth of new information since deviations from a perfect structure have crucial impact on the properties. My objectives will enable the understanding at the atomic level of reasons behind thermal and moisture degradation of MOFs. My project will provide the much needed understanding of the fundamentals for better engineering of MOFs. Finally, I envision that the newly developed methodologies will also enable imaging of a broad class of nanomaterials that could not be studied by TEM so far because of beam sensitivity.

Researcher(s)

• Promoter: Bals Sara
• Fellow: Kavak Safiyye

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Recent experimental and theoretical efforts in the shaping and texturing of the electron wave-function take as an example periodic arrangement of atoms in a crystal that appear in nature. For example, as observed in semiconductors, electrons acquire new properties depending on the types of atoms and their arrangement in the lattice: the spectrum becomes gapped, electrons and holes acquire effective masses, etc. In efforts to mimic this behavior and with the purpose of tuning it at will, researchers have created through various means periodic potentials for two-dimensional electron gas systems. These can be either the states formed at the interface of two semiconductors, the surface state in metals, or the naturally confined electrons in two-dimensional materials like graphene. Based on very recent experimental developments, we propose to theoretically study a sandwich-like configuration containing patterned graphene gates, imposing a periodic potential on a bilayer graphene active layer. The main goal is to artificially create and tune lattices with peculiar properties, otherwise not easily found in nature: Lieb, kagome or dice lattices that show flat electronic bands with topological properties and show great potential for novel physics. This proposal is situated in the context of a collaboration with an experimental group working on building such devices. The planned close interaction will provide input on realistic gate configurations, possibility to validate our approach, to model electric transport measurements in the presence of magnetic fields and to predict gate configurations which realize the propose flat topological bands.

Researcher(s)

• Promoter: Covaci Lucian
• Fellow: Aerts Emile
• Fellow: Verstraeten Ivan

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This project aims to develop the achitectures of sulphur- and lithiumelectrodes to improve the properties and lifetime of the next generation of batteries, i.e. lithium sulfur batteries (LSB). The innovative sulphurelectrodes provide a simultaneous increase of the sulphur load and stability of electronic/ionic contacts over long and short distances in the cel. This is achieved through an approach based on the gradual decoration of sulphur particles and electrodes by the so-called traps of the polysulfide (PS-trap). The project also aims to increase the safety and energy density of the LSB's by developing thin protected lithiumelectrodes.

Researcher(s)

• Promoter: Hadermann Joke

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

4AirCRAFT's ultimate goal is to develop a next generation of stable and selective catalysts for the direct CO2 conversion into liquid fuels for the aviation industry, enabling the synthesis of sustainable jet fuel. 4AirCRAFT will overcome the current challenges by combining three main reactions into one reactor to increase the CO2 conversion rate and reduce energy consumption. 4AirCRAFT technology will produce sustainable jet fuel at low temperature (below 80 ºC), contributing to a circular economy and leading to a decrease in GHG and reduced dependence on fossil fuel-based resources. In order to achieve this goal, we will move beyond the SoA by precisely integrating and taking advantage of biocatalysts, inorganic nanocatalysts, electrocatalysts, and their controlled spatial distribution within application tuned catalyst carrier structures. These catalyst carrier structures will be based on metal-organic frameworks and engineered inorganic scaffolds with hierarchical porosity distribution. This will unravel the activity of catalytic active phases and materials based on earth-abundant elements allowing us to achieve high CO2 conversion percentages and selectivity towards jet fuels (C8−16). By achieving this we will be able to circumvent the need for Fischer–Tropsch synthesis, that is unselective for the synthesis of fuels, therefore eliminating further steps for hydrocracking or hydrorefining of Fischer–Tropsch waxes. In terms of inorganic catalysts, size and shape of metal NPs, metal clusters, and single atoms at the surface of catalyst carrier structures will be developed, and precise structure-performance-selectivity relationships will be established. In terms of biocatalyst, special emphasis will be given to assure the long-term stability of deployed enzymes through programmed anchoring and shielding from detrimental reaction conditions. Together application tuned catalyst carrier structures will be employed to steer selectivity towards C8−16 molecules.

Researcher(s)

• Promoter: Hadermann Joke
• Co-promoter: Canossa Stefano

Research team(s)

• Electron microscopy for materials research (EMAT)

Project website

Project type(s)

• Research Project

Abstract

The atomic structure determination of inorganic, organic and macromolecular compounds is a hard challenge anytime the crystal size falls below the micron range, becoming no more suitable for single-crystal x-ray diffraction. Still, a number of chemicals with valuable commercial and medical implications can be synthesized only as nanocrystals or show phase/polymorphic transitions during crystal growth. The development of more efficient tools able to disclose the nature of nanocrystalline materials is therefore a hot and transversal topic that links materials science, physics of diffraction, new instrument engineering, chemical production and pharmacology. Electron diffraction (ED) allows extracting structure information from single nanometric crystals. ED experienced a tremendous boost after the development of 3D routines for data collection, up to be enlisted among the main breakthroughs in Science. However, the development of 3D ED is still limited to few laboratories and is slowed by the lack of dedicated instrumentation. NanED aims to form a new generation of electron crystallographers, able to master and develop 3D ED techniques in an interdisciplinary and interconnected network, where competences and know-how of usually distant scientific sectors are shared and merged. NanED will gather all European scientists hitherto active in 3D ED development and a pool of large and small companies interested in instrument development and material or pharmaceutical production. NanED will deliver portable procedures for sample preparation, data collection and data analysis, suitable for the successful application of 3D ED to all kinds of compounds. NanED will also establish a new standard of crystallographic training, closer to nowadays industrial needs. Finally, NanED will favor the dissemination of 3D ED in academic and industrial laboratories, pushing Europe to be the leader for nanomaterial characterisation and development, with a noticeable and global economic impact.

Researcher(s)

• Promoter: Hadermann Joke

Research team(s)

• Electron microscopy for materials research (EMAT)

Project website

Project type(s)

• Research Project

Abstract

Electron microscopy (EM) is a key technology to reveal the atomic structure and chemical composition of materials with (sub-)Ångström resolution. It is an essential technique to enable the breakthroughs that are needed to solve societal challenges in renewable energy technology, life sciences, and communication and quantum technology. To realize these breakthroughs, we require EM technology with ultrafast time scale, ultrahigh energy resolution, covering low-energy spectral ranges and several other capabilities, all of which are beyond the present state of the art. The EBEAM project brings together a proven consortium of EM experts that will integrate their complementary EM science and technology into completely new EM measurement modalities, exploiting the unique interactions between free electrons and optical light fields, and thereby combining ultrahigh spectral and temporal control with sub-Ångström spatial resolution. The project's ambition is to demonstrate <20 fs time resolution and <1 meV energy resolution, and to open up the 4-400 neV (1-100 MHz) energy range, all inaccessible in EM so far. Using new correlation and coincidence modalities that have never been used in EM before, we will unveil new methods to probe selection rules, low-energy band structures, trace elements, and more. We will demonstrate the broad applicability of the new EBEAM techniques by carrying out selected research projects that target key questions in energy conversion materials, opto-electronic materials and quantum technology. The consortium is composed of 8 EM groups in basic research and industry that represent a unique combination of EM instruments, knowledge and ideas that are well positioned to target the ambitious goals of the EBEAM project. It includes the world-leader in EM manufacturing and a successful SME. Together, the consortium will bring the EBEAM technology to a broad user community where it is expected to have strong scientific and economic impact.

Researcher(s)

• Promoter: Verbeeck Johan

Research team(s)

• Electron microscopy for materials research (EMAT)

Project website

Project type(s)

• Research Project

Abstract

Recently, Prof. Masuhara's group reported a new phenomenon in the optical capture of nanoparticles: particles move like a swarm outside the focus! The effective irradiation area in the optical trap is increased by multiple photon scattering from the formed (nano/micro) assembly. This phenomenon is now called 'Optically Evolved Assembling'. Phenomenologically, the optically evolved assembly/swarm is easy to understand: initially a limited number of nanoparticles are attached to the interface, well within the focal volume, resulting in a small swarm. The captured NPs scatter the light in the optical trap, increasing the out-of-focus optical potential. This allows new nanoparticles to catch up in the swarm and enhance the effect. The concept of "Optically Evolved Assembling" is completely new and has a lot of (practical) potential for light-induced material production in the future. Indeed, achieving a level of control over the nanoscale self-organized collective motion in liquid environments, similar to what has been achieved when manipulating nanoscale objects on surfaces and in high vacuum environments, could revolutionize many aspects of nanotechnology and colloidal science. This scientific research network aims to develop a comprehensive model for the "Optically Evolved Assembling" formation at the nanoscale that goes beyond the intuitive understanding we now have. Optical (scattering, gradient and absorption) forces are at the heart of the observed assemblages/swarms, but the hitherto unexplored hydrodynamic effects probably also play a crucial role. To map these, we will perform super-resolution optical imaging of the different dynamic assemblies under different optical capture conditions to unravel the individual and collective motion of the particles in the assemblage/swarm. We will compare the obtained experimental information with calculated theoretical models and simulations to further prove our developed models.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Light detection and emission are crucial for displays, medical and security scanners. Given the societal relevance, there is an emerging need for novel opto-electronic materials with higher conversion effi-ciency and lower production cost. Metal halide perovskites are promising high-performance semicon-ductors due to their strong absorption and emission in a broad spectral range and their ease of manu-facturing. So far, integration in opto-electronic devices was hampered by inherent stability issues such as the degradation from the optically active "black" phase into an inactive phase. Based on our recent proof-of-concept, we will explore a fundamentally new paradigm to stabilize the black phase under ambient conditions. This innovative concept exploits strain engineering, with thin films fixed to sub-strates and/or patterned at the nano- to micrometer scale. PERsist builds on the synergy between leading experts in high-end micro/spectroscopy & modelling of nanomaterials.

Researcher(s)

• Promoter: Bals Sara
• Co-promoter: Van Aert Sandra
• Co-promoter: Verbeeck Johan

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The aim of this project is to quantify the 3D dynamics of complex nanostructures at the atomic scale when they evolve over time via adatom dynamics, surface diffusion or during in situ experiments. This highly challenging and innovative objective will be reached by combining novel data-driven statistical methods with new image detection capabilities in aberration corrected scanning transmission electron microscopy. The ability to follow the motion of individual atoms in 3D in a realistic environment will clearly take the characterisation of nanomaterials to the next level. Quantitative 3D characterisation of nanostructures can nowadays be achieved with high reliability for systems under stationary conditions. Yet, major problems exist to get insight into the 3D dynamics because of the lack of physics-based models, detailed statistical analyses, and optimal design of experiments in a self-consistent computational framework. Machine learning using a hidden Markov model will enable us to explicitly describe structural changes as a function of time and to fully exploit the temporal information available in the observations. This unique approach will result in a precise characterisation of complex nanostructures in response to environmental stimuli such as temperature, pressure or gas composition. Clearly this is a prerequisite to understand the unique link between a material's structure and its properties, which is important for the design of a broad range of nanomaterials.

Researcher(s)

• Promoter: Van Aert Sandra

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Individual point defects in diamond crystals belong to an important class of quantum systems denoted as solid-state qubits. Such point defects, as for example NV, SiV, are intensively studied in the field of quantum sensing and metrology but also quantum information science. The applicants recently developed a novel technique, photoelectrically detected spin resonances in diamond, which brings promises for a new category of quantum devices that can be coupled with classical semiconducting electronics. The photoelectric readout is fundamentally based on charge state transitions in single point defects. In this respect, the photoelectric method differs from optical detection in two level quantum systems. In our proposal we would like to use this basic property of photoelectric readout and realise a novel type of qubit - charge-state solid qubit - using the transition between the different charge state of the same defect. Combining with the spin manipulations a hybrid quantum systems can be conceived. The proposal is based on preliminary results demonstrating the SiV charge state readout. To devise the mechanism of charge state transitions we will use predictive ab initio calculations theoretical methodology, permitting to determine the energy position of charge state levels in the diamond gap, photoionisation cross section, rates and the electron transport coherence with respect to the driving field. We will demonstrate charge-qubit superposition and two qubit entanglement.

Researcher(s)

• Promoter: Lamoen Dirk
• Co-promoter: Partoens Bart

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The European Training Network CATCHY provides a concerted effort to design novel high-performance thermo- and electrocatalysts for the conversion of CO2 into added-value synthetic fuels, while delivering a unique range of training opportunities providing young researchers with the expertise and skills required by employers in nanotechnology. Catalysis research is dedicated to the understanding and optimization of existing catalysts and the tailor-made design of new materials with a focus on high-activity, high-selectivity, and economic feasibility. CATCHY will tailor new high performance CO2 conversion catalysts by a new multidisciplinary catalysis-by-design approach combining: i. production of bimetallic gas phase clusters of controlled homogeneity mixing transition, noble, and post-transition metals and deposition on various supports; ii. extensive characterization of their morphology (ex situ and in situ) ; iii. fundamental experimental and theoretical reactivity studies; and iv. (electro)catalytic laboratory tests. A prototype of the most promising electrocatalyst will be tested under realistic operative conditions. CATCHY offers an interactive training approach combining new capabilities for the fabrication and characterization of cluster-based nanostructured surfaces to produce innovative applications. A complementary academic and industrial environment ensures an intersectorial training programme. Industry oriented training will be provided by focusing on selected catalysis applications directly related to energy and climate change issues of paramount importance to the EU and the world. The balanced program combines local expert training by academia and industrial partners, a networkwide secondment scheme, and network-wide training. The societal and environmental urgency to mitigate adverse climate change effects in the coming decades, and the particular advanced catalyst design approach, will guarantee the employability of CATCHY's young researchers.

Researcher(s)

• Promoter: Bals Sara
• Co-promoter: Altantzis Thomas

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The properties of nanomaterials are essentially determined by their three dimensional (3D) structure. Electron tomography currently enables one to measure the morphology and composition of nanostructures in 3D, even with atomic resolution. Strikingly however, these measurements are always performed at room temperature and in ultrahigh vacuum, which are conditions that are completely irrelevant for the use of nanoparticles in real applications. Moreover, nanoparticles often have ligands at their surface, which form the interface to the environment. They influence the growth, thermal stability and drive self assembly. Surprisingly, their exact role has not yet been completely understood and so far, their presence has been completely neglected during electron microscopy investigations. The aim of this program is to overcome these crucial limitations and to enable a deep understanding of the effect of a relevant climate on the structure-property connection of a broad range of nanoparticles and their assemblies. Since two dimensional in situ electron microscopy experiments are simply not sufficient to understand the complex 3D changes in anisotropic nanosystems, I will develop innovative 3D characterization tools, compatible with the fast changes of nanomaterials that occur in a thermal and gaseous environment. To visualize surface ligands without damaging their structure, I will combine direct electron detection with exit wave reconstruction techniques. Tracking the 3D structure of nanomaterials in a relevant climate is an extremely ambitious goal. However, the preliminary experiments in this application demonstrate the enormous impact. Our objectives will enable 3D dynamic characterization of reshaping of nanoparticles, important to improve thermal stability during drug delivery, sensing, data storage or hyperthermic cancer treatment. We will provide quantitative 3D measurements of the coordination numbers of the surface atoms of catalytic nanoparticles and follow the motion of individual atoms live during catalysis. By visualising surface ligands and their interface with nanoparticles in 3D, we will understand their fundamental influence on particle shape and during self assembly. This program will be the start of a completely new research line in the field of 3D imaging at the atomic scale. Even more essential is that the outcome of these challenging studies will certainly boost the design and performance of nanoparticles. This is not only of importance at a fundamental level, but is a prerequisite for the incorporation of nanomaterials in our future technology.

Researcher(s)

• Promoter: Bals Sara
• Fellow: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Nanomaterials play a key role in modern technology and society, because of their unique physical and chemical characteristics. The synthesis of nanomaterials is maturing but surprisingly little is known about the exact roles that different experimental parameters have in tuning their final properties. It is hereby of crucial importance to understand the connection between these properties and the (three-dimensional) structure or composition of nanomaterials. The proposed consortium will focus on the design and use of nanomaterials in fields as diverse as plasmonics, electrosensing, nanomagnetism and in applications such as art conservation, environment and sustainable energy. In all of these studies, the consortium will integrate (3D) quantitative transmission electron microscopy and X-ray spectroscopy with density functional calculations of the structural stability and optoelectronic properties as well as with accelerated molecular dynamics for chemical reactivity. The major challenge will be to link the different time and length scales of the complementary techniques in order to arrive at a complete understanding of the structure-functionality correlation. Through such knowledge, the design of nanostructures with desired functionalities and the incorporation of such structures in actual applications, such as e.g. highly selective sensing and air purification will become feasible. In addition, the techno-economic and environmental performance will be assessed to support the further development of those applications. Since the ultimate aim of this interdisciplinary consortium is to contribute to the societal impact of nanotechnology, the NanoLab will go beyond the study of simplified test materials and will focus on nanostructures for real-life, cost-effective and environmentally-friendly applications.

Researcher(s)

• Promoter: Bals Sara
• Co-promoter: De Wael Karolien
• Co-promoter: Janssens Koen
• Co-promoter: Lenaerts Silvia
• Co-promoter: Milosevic Milorad
• Co-promoter: Neyts Erik
• Co-promoter: Van Aert Sandra
• Co-promoter: Van Passel Steven
• Co-promoter: Verbruggen Sammy

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Using microtomy, thin slices of 60, 80 and 100 nm are made of an NiCrFe alloy. The sample preparation was successful. The slices will be used for synchrotron STXM measurements by the Universiteit Gent.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Most large-scale geological process such as plate tectonics or mantle convection involve plastic deformation of rocks. With most recent developments, constraining their rheological properties at natural strain-rates is something we can really achieve in the decade to come. Presently, these reological properties are described with empirical equations which are fitted on macroscopic, average properties, obtained in laboratory experiments performed at human timescales. Their extrapolation to Earth's conditions over several orders of magnitude is highly questionable as demonstrated by recent comparison with surface geophysical observables. Strain rates couple space and time. We cannot expand time, but we can now reduce length scales. By using the new generation of nanomechanical testing machines in transmission electron microscopes, we can have access to elementary deformation mechanisms and, more importantly, we can measure the key physical parameters which control their dynamics. At this scale, we can have access to very slow mechanisms which were previously out of reach. This approach can be complemented by numerical modelling. By using the recent developments in modelling the so-called "rare events", we will be able to model mechanisms in the same timescales as nanomechanical testing. By combining, nanomechanical testing and advanced numerical modelling of elementary processes we will elaborate a new generation of rheological laws, based on the physics of deformation, which will explicitly involve time (i.e. strain rate) and will require no extrapolation to be applied to natural processes. Applied to olivine, the main constituent of the upper mantle, this will provide the first robust, physics-based rheological laws for the lithospheric and asthenospheric mantle to be compared with surface observables and incorporated in geophysical convection models.

Researcher(s)

• Promoter: Bals Sara
• Promoter: Schryvers Nick

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Atomic resolution microscopy relies on beams of energetic electrons. These beams quickly destroy fragile materials, making imaging them a major challenge. I have recently developed a new approach that provides the greatest possible resolving power per electron. The method provides both double resolution and excellent noise rejection, via multidimensional data acquisition and analysis. Here I propose to couple the new method with breakthroughs in high speed cameras to achieve unprecedented clarity at low doses, almost guaranteeing major advances for imaging beam sensitive materials. Proof of principle will be achieved for biochemical imaging using the easy to handle, commercially available GroEL chaperone molecule. We will combine our enhanced imaging capabilities with the averaging methods recently recognized by the Nobel prize in chemistry for imaging biomolecules at ultra low doses. After proving our low dose capabilities we will apply them to imaging proteins of current interest at greater resolution. Similar techniques will be used for fragile materials science samples, for instance metal organic framework, Li ion battery, 2D, catalyst and perovskite solar cell materials. Furthermore the same reconstruction algorithms can be applied to simultaneously acquired spectroscopic images, allowing us to not only locate all the atoms, but identify them. The properties of all materials are determined by the arrangement and identity of their atoms, and therefore our work will impact all major areas of science, from biology to chemistry and physics.

Researcher(s)

• Promoter: Pennycook Timothy

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Computational modeling is an essential factor in the study of the properties of materials. Nowadays, computational modeling is extensively used to predict and develop new materials. This requires a thorough knowledge of the local atomic (structural and electronic) structure and its influence on the macroscopic properties. Although, in principle, all materials can be described with the laws of quantum mechanics, it is impossible in practice to derive all material properties from these. Even with today's most powerful supercomputers, quantum mechanical electronic structure calculations are limited to a thousand atoms and to a maximum of 1 ns. To study length and time scales that go beyond these atomic scales, (semi-) empirical techniques are used and further developed through multiscale modeling. Transitions between models describing at different time and length scales are achieved by studying the relevant scale with the appropriate computational techniques. In order to have a thorough understanding of materials properties it is therefore important for collaborations between computational groups with expertise on different methods to flourish.

Researcher(s)

• Promoter: Lamoen Dirk

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

In the field of materials science and nanoscience, precise structure determination is important in order to understand the relation between structure and properties by comparison with theoretical ab-initio calculations. In combination with recent developments in nanotechnology, where one is able to make nanostructures with a well-chosen and controlled structure, an evolution toward materials design may be realized. The purpose of this project is to realize a breakthrough toward quantitative characterization of nanostructures. Therefore, use will be made of model-based electron microscopy. Starting from experimental data, physical parameters characterizing the structure of a material will be measured as precisely and accurately as possible. The methodology proposed in this project to obtain precise measurements of parameters is also applicable to several other branches of science, particularly those branches where one acquires data at the limit of what is physically measurable.

Researcher(s)

• Promoter: Van Aert Sandra
• Fellow: Van Aert Sandra

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Bals Sara
• Promoter: Van Tendeloo Staf

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Characterisation of biopolymers using low-dose secondary electron and backscatter electron imaging in an environmental scanning electron microscope. The analysis frame in the study of transition metal recovery processes in waste waters.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Age hardenable Al-Cu-Mg alloys are widely used in aerospace and automotive industries due to their excellent specific strength, good formability and good corrosion resistance. The strength of the Al-Cu-Mg alloy mainly comes from the nano-scale precipitates formed during artificial ageing treatment. The main strengthening precipitates in the high Cu/Mg ratio Al-Cu-Mg alloy are S'-Al2CuMg, θ''-Al3Cu and θ'-Al2Cu. S'-Al2CuMg and θ'-Al2Cu have an excellent thermal stability in room temperature. However, the S'-Al2CuMg and θ'-Al2Cu may rapidly grow and coarsen when the temperature goes above 150 °C and 200 °C, respectively. The coarsened precipitates will lead to a rapid decline in mechanical properties. In order to improve the heat resistance of Al-Cu-Mg alloys, it is particularly important to improve the thermal stability of the metastable strengthening precipitates.

Researcher(s)

• Promoter: Schryvers Nick

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The main objective of the TEM characterizations is to elucidate the fundamental micro/nanoscopic mechanisms controlling healing of damages in Aluminum alloys elaborated in UCLouvain. Ex-situ advanced TEM techniques such as aberration corrected TEM, automatic crystallographic orientation and nanostrain mapping in TEM as well as analytical TEM will be used to characterize defects and interfaces while quantified in-situ TEM testing will be performed in order to directly observe the mechanisms under interest inside the microscope. TEM thin foils for the ex-situ and in-situ TEM characterizations will be prepared in EMAT.

Researcher(s)

• Promoter: Schryvers Nick

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Through this collaboration EELS analysis are done at TEM microscopes at EMAT and support for EELS analysis is given on UTwente microscopes by a highly trained EMAT postdoc upon request by UTwente researchers.

Researcher(s)

• Promoter: Verbeeck Johan

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Chiral features in metal nanoparticles (NP) result in chiroptical properties, of interest to many applications, such as enantioselective catalysis or separation, chiral sensing or drug delivery. These applications arise from the different interactions of chiral plasmonic NPs with left- and right-handed circularly polarized light (CPL). Therefore, much effort has been put into the development of NPs with complex structures and morphologies. The properties of such nanomaterials are usually characterized by measuring their circular dichroism (CD), which quantifies the interaction of an ensemble of particles with CPL. Multiple factors can be at the origin of the recorded CD signal, such as a helical morphology, chiral features in the crystalline structure, or the presence of chiral molecules at or near the surface of the chiral NPs. Unfortunately, there is no consensus on the relative importance of these different aspects. To obtain NPs with tailored chiroptical properties, it is thus important to understand the connection between the CD signal and the NP morphology. Transmission electron microscopy (TEM) is an excellent technique to investigate the structure of nanomaterials. Several approaches, within the field of expertise of EMAT, can be used to investigate the morphology, structure or properties of chiral nanoparticles. Examples include 3D structural characterization by scanning electron microscopy (SEM), electron tomography in real and reciprocal space and electron beam induced current measurements (SEEBIC). Moreover, there is still debate in the field on the application of electron energy loss spectroscopy (EELS) to measure chiral features of nanoparticles. Although these techniques are already being developed at EMAT in the framework of other projects, their combined application to chiral nanoparticles will require further development. For example, identification of chiral surface facets is currently impossible due to a lack of 3D resolution by electron tomography or SEEBIC. Visualisation of chiral molecules and micelles that lie at the origin of the growth of chiral nanoparticles is another challenge that will require the development of low-dose imaging techniques, ideally combined with in situ TEM to generate a relevant, liquid, environment. Moreover, quantification procedures, e.g. to define the degree of helicity will need to be developed. Such computational techniques, eventually based on the use of training a neural network as well as modeling of the connection between structure and properties are challenging aspects but the knowhow to help talented postdocs to overcome current limitations is available at EMAT.

Researcher(s)

• Promoter: Bals Sara
• Co-promoter: Lamoen Dirk
• Co-promoter: Verbeeck Johan
• Fellow: Mychinko Mikhail

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Inorganic nanoparticles and nanostructures with complex morphologies have gained increasing scientific interest, because of the possibility to tune their ability to interact (polarized) light. In some cases, the optical activity is hypothesized to originate from a specific morphology of the nanomaterial. However, quantifying the morphology of objects with sizes of tens of nanometers is far from straightforward. Electron tomography offers the possibility to faithfully retrieve the three-dimensional morphology of nanomaterials, but only a qualitative interpretation of the morphology of nanoparticles has been possible so far. I recently introduced a method to quantify the helicity of complex nanomaterials at the single particle level starting from high-quality electron tomography reconstructions. However, in order to provide significant insights into the fundamental origin of optical properties, further progress is required. Therefore, I will apply quantitative electron tomography (EMAT, University of Antwerp) and perform ensemble and single particle VIS-NIR spectroscopy (AMOLF Institute, Amsterdam). By combining these results, I will carry out a systematic investigation of different types of nanoparticles prepared in the group of Professor Luis Liz-Marzán (CICBiomagune, San Sebastián). I envisage that I will provide critical feedback to improve the synthesis and the optical activity of these exciting materials.

Researcher(s)

• Promoter: Bals Sara
• Fellow: Heyvaert Wouter

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

By using Focussed Ion Beam - Scanning Electron microscopy and Transmission Electron Microscopy - Energy Dispersive X-ray diffraction the interaction between Al2O3 and polyimide layers has been studied.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The main objective of the TEM characterizations is to elucidate the fundamental micro/nanoscopic mechanisms controlling healing of damages in Aluminum alloys elaborated in UCLouvain. Ex-situ advanced TEM techniques such as aberration corrected TEM, automatic crystallographic orientation and nanostrain mapping in TEM as well as analytical TEM will be used to characterize defects and interfaces while quantified in-situ TEM testing will be performed in order to directly observe the mechanisms under interest inside the microscope. TEM thin foils for the ex-situ and in-situ TEM characterizations will be prepared in EMAT.

Researcher(s)

• Promoter: Schryvers Nick

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

By using Transmission Electron Microscopy - Energy Dispersive X-ray diffraction, the location of silver nanoparicles was studied in zeolite samples. The samples have been crushed as preparation for TEM.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Dedicated TEM imaging techniques have been used in order to determine the location and size distribution of silver nanoparticles in zeolites. TEM tomography was used in order to do this characterisation in 3D.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The goal of the FUNY project is to functionalise powders in order to improve for example their adhesive or dispersive characteristics, or their hydrophobicity or hydrophilicity, depending on tthe industrial application.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Metal halide perovskites (MHP) are promising semiconductors for the next generation of optoelectronic applications because of their excellent performance and low-cost processability. Unfortunately, applications are hampered by the lack of stability when MHPs are exposed to relevant conditions. To overcome this limitation, precise knowledge of the structure-property relationship in MHPs is required. Therefore, this project aims to develop novel and advanced transmission electron microscopy (TEM) techniques for in situ experiments, during which MHPS will be exposed to environmental conditions. Hereby, the development of low dose TEM techniques is crucial because of the high electron beam-sensitivity of MHPs. These techniques will be combined with in situ experiments under heat, gaseous environment, and high bias. Based on the outcome of my experiments, I will be able to provide a better understanding of promising stabilization methods such as interfacial clamping. I will hereby reveal the influence of interfacial defects and grain boundary types in textured MHP thin films. Moreover, the local results obtained by TEM will yield novel insights on degradation mechanisms under high bias, oxygen or moisture. In this manner, my project will provide the necessary input to trigger novel strategies for long-term stability of MHPs.

Researcher(s)

• Promoter: Bals Sara
• Fellow: Schrenker Nadine

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The overarching goal of MUMMERING is to create a research tool that encompasses the wealth of new 3D imaging modalities that are surging forward for applications in materials engineering, and to create a doctoral programme that trains 15 early stage researchers (ESRs) in this tool. This is urgently needed to prevent that massive amounts of valuable tomography data ends on a virtual scrapheap. The challenge of handling and analysing terabytes of3D data is already limiting the level of scientific insight that is extracted from many data sets. With faster acquisition times and multidimensional modalities, these challenges will soon scale to the petabyte regime. To meet this challenge, we will create an open access, open source platform that transparently and efficiently handles the complete workflow from data acquisition, over reconstruction and segmentation to physical modelling, including temporal models, i.e. 3D "movies". We consider it essential to reach this final step without compromising scientific standards if 3D imaging is to become a pervasive research tool in the visions for Industry 4.0. The 15 ESRs will be enrolled in an intensive network-wide doctoral training programme that covers all aspects of 3D imaging and will benefit from a varied track of intersectoral secondments that will challenge and broaden their scope and approach to research.

Researcher(s)

• Promoter: Bals Sara
• Fellow: Chen Qiongyang

Research team(s)

• Electron microscopy for materials research (EMAT)

Project website

Project type(s)

• Research Project

Abstract

Transmission electron microscopy is an indispensable characterization tool for many applications in materials and life science. During the last 2 decades, enormous progress was made concerning aberration correctors, novel detectors and samples holders. Still, there is a lot of room for further improvement of TEM experiments by optimizing the carbon support grids that are hereby used. Graphene grids have the potential to bring TEM measurements of low-contrast and beam sensitive samples to the next level. Unfortunately, while being relatively expensive, the quality of commercially available grids is extremely poor. The aim of HYPERGRAPH is to produce high quality graphene grids yielding high coverage, extreme flatness and cleanness at a cost that is at least 4 times lower than what is the current standard. We will also improve throughput, reproducibility and shelf live. This project will bring a variety of TEM investigations to a next level. In this manner, HYPERGRAPH will be of crucial importance for the further development of (nano)materials in fields as broad as catalysis, sensing, medicine and energy applications.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The 4D characterisation of nanoparticles, i.e., the time evolution of their 3D structures, is essential to understand their transient behaviour under external stimuli such as temperature and pressure. A recent revolution in transmission electron microscopy has made it possible to perform in-situ tomography experiments; hence 4D imaging is within reach. However, novel computational tools are urgently required since the conventional imaging methods fail to produce stable 4D images. 4D-ATOM will develop algorithms and computational techniques to enable 4D imaging of nanoparticles using compressed shape sensing. In particular, 4D-ATOM will construct a numerical scheme based on a dynamic level-set method to track the changes in nanoparticles during their heating or chemical transformations. Moreover, 4D-ATOM will design compressive measurement patterns to facilitate ultra-fast in-situ electron tomography for imaging beam-sensitive nanoparticles. The results of 4D-ATOM will be state-of-the-art in nanotechnology and open up an entirely new set of exciting experiments in the field of electron tomography. These tools will enable researchers to understand and overcome degradation mechanisms for sensitive structures such as metal halide perovskite materials, with applications for solar cells or X-ray detectors. Moreover, understanding the dynamic evolution of the nanoparticles' structure during catalysis will enable one to boost the efficiency and stability of the catalytic process.

Researcher(s)

• Promoter: Bals Sara
• Fellow: Kadu Ajinkya Anil

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Bimetallic MPt (M: Fe, Co, Ni) nanoparticles (NPs) displaying anisotropic morphologies are of great interest for the electrocatalytic oxygen reduction reaction (ORR). Unfortunately, MPt alloys in their native A1 phase rapidly degrade in acidic media and therefore severely restrict fuel cell applications. High temperature thermal annealing of CoPt and FePt NPs to achieve its chemically ordered L10 phase is crucially required to achieve an acid-stable catalyst and boost ORR activity to make fuel cells a financially viable technology. In CATOM, my goal is to establish a controlled route to thermally induce the L10 phase whilst protecting the catalyst morphology, achieving ORR performance and acid-stability within the same NP. I will gain the necessary insights to reach this ambitious goal by exploiting advanced electron microscopy (EM) techniques. Due to the complex NP morphologies, these investigations must be performed in 3D. I will therefore develop innovative quantitative electron tomography techniques to track atom-level dynamics and morphology evolution during the annealing process on the single particle level. Moreover, combining in situ gas cell annealing data with computational simulations will enable me to follow the 3D structure evolution of MPt alloys under realistic industrial conditions with atomic resolution. Finally, the direct comparison of A1 and L10 stability of faceted NPs during electrochemical cycling using a liquid cell holder will allow me to compare activation and degradation processes between the phases and to couple catalyst evolution with its ORR performance. These innovative experiments could not be obtained so far because of a lack of 3D characterization tools suitable to track NP evolution under realistic conditions. The outcome of my program will fundamentally advance in situ EM characterization techniques and direct future catalyst design to prepare highly active and acid-stable ORR catalysts critically needed for fuel cell development.

Researcher(s)

• Promoter: Bals Sara
• Fellow: Jenkinson Kellie

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

In-situ nano-mechanical TEM straining of 3 samples of freestanding ZrSix films and the investigation of the effect of point defects. Measure stress-strain curve for strongest most promising sample: can plasticity can be detected? Compare with weakest: is difference in apparent strength contributed to by the difference in plasticity? In-situ TEM, mechanisms of plastic deformations: dislocations, grain rotation and grain boundary sliding?

Researcher(s)

• Promoter: Schryvers Nick

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This agreement allows Drs. Tong Yang from the Central South University, Changsha, Hunan, China, to join in TEM experiments at the EMAT laboratory of the University of Antwerp, Belgium, on 5 samples provided by Prof. Dr. Yaoxue Zhang and Prof. Dr. Kai Li of the State Key Lab of Powder Metallurgy, Central South University, Changsha, Hunan, China. A systematic method will be established for quantitative characterization of multiscale 3D structure experiments of Al alloys. The samples will be investigated using in-situ nanomechanical testing with the Push-to-Pull Hysitron sample holder in the Osiris and/or Tecnai microscopes and by analytical characterization on Titan instruments. The samples will be produced by FIB or electropolishing at the EMAT laboratory by or with the support of EMAT personnel. The TEM experiments will be conducted by Drs. Tong Yang under supervision and with support of EMAT researchers and staff. Sessions on FIB and TEM instruments will be designated following regular EMAT rules.

Researcher(s)

• Promoter: Schryvers Nick

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The main objective of the TEM characterizations is to elucidate the fundamental micro/nanoscopic mechanisms controlling healing of damages in Aluminum alloys elaborated in UCLouvain. Ex-situ advanced TEM techniques such as aberration corrected TEM, automatic crystallographic orientation and nanostrain mapping in TEM as well as analytical TEM will be used to characterize defects and interfaces while quantified in-situ TEM testing will be performed in order to directly observe the mechanisms under interest inside the microscope. TEM thin foils for the ex-situ and in-situ TEM characterizations will be prepared in EMAT.

Researcher(s)

• Promoter: Schryvers Nick

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The study of the structure of nanocrystalline materials is often difficult as standard X-ray diffraction techniques break down for sub micrometer particles, especially when occurring in a mixture. This is resolved by trying to crystallize specific compounds in larger crystals, but this is often problematic and time consuming. State of the art single crystal X-ray diffraction moreover requires a trip to a synchrotron which creates unnecessary long delays between growing a new structure and determining its structure. Electron diffraction provides an alternative for X-ray diffraction and excels especially for nanoscale crystals as it provides several orders of magnitude more information per volume for the same radiation damage. However, so far, electron diffraction is performed on expensive and difficult to handle transmission electron microscopes (TEM) requiring extensive interaction from highly trained researchers. This makes the technique rather unattractive for industrial demands where ease of use, high throughput, statistics and reproducibility are key concerns that don't fit well with the reality of TEM instruments in university labs. In this project, we propose to build a prototype electron diffractometer instrument on the basis of a modest Scanning Electron Microscope (SEM). The instrument will take a properly prepared nanocrystalline powder and automatically perform a full diffraction analysis on a very large number of particles without human interaction. This data is then fed into an automated structure refinement program and results in a full report on the structure and abundance of the particles found. An in house proof of concept shows that the obtained quality of diffraction data is excellent although several scientific issues will require attention. We propose to demonstrate this instrument on industry relevant materials in close interaction with several companies in Flanders that expressed strong interest in the capabilities of such instrument.

Researcher(s)

• Promoter: Verbeeck Johan
• Co-promoter: Hadermann Joke

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The salinity gradients that occur where fresh water flows into salty ocean water represent a very large and almost completely untapped source of clean, so called blue energy, based on osmosis. One reason blue energy remains untapped is the inefficiency of current methods to harvest it, mostly due to the poor performance of the membrane processes being used. A promising potential solution to this problem is to use atomically thin 2D materials with nanopores in them as the membranes. Proof of principle experiments with nanopores in 2D materials have demonstrated osmotic power densities up to six orders of magnitude better than conventional membranes. Charge buildup around the nanopores creates a filter that allows salt ions with only one sign of charge to be driven by the chemical potential gradient from a salty reservoir through the pores and into a fresh water reservoir. Much like in a battery, the resulting segregated charge build up creates an electrical potential difference that can be used for electrical power. However, in order to enable maximum efficiency power generation from blue energy, a better understanding of the nanopores is needed. At present even basic knowledge such as their atomic structures remains lacking. In this project we will determine the atomic structure of nanopores which have been characterised for blue energy performance and develop methods of probing the charge density and electric fields at and around the nanopores with electron microscopy. In conjunction with first principles theory we will use the correlations between blue energy performance and the findings of the microscopy experiments to understand the physics of osmotic power production with nanopores in different 2D materials. We will thus uncover what makes the best nanopore based membranes, facilitating the engineering of nanopores with optimal blue energy performance.

Researcher(s)

• Promoter: Pennycook Timothy
• Fellow: dos Santos Gomes José Nuno

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

We rely on materials science for progress in nearly every area of technology, to help us solve a variety of challenges. Materials science, in turn, relies the availability of characterisation techniques to help understand the behaviour and properties of materials, so that they can be engineered. Transmission electron microscopy is an important tool to this end, allowing us to probe the structure of materials and many of their properties with unrivalled resolution. Electron energy loss spectroscopy (EELS) is one of the most popular characterisation methods available in TEMs, allowing to investigate composition and much more by analysing the energy lost by the electrons in the beam by interacting with the sample. I want to broaden the scope of properties that can be measured with nanoscale resolution by analysing not only the energy loss but also the momentum exchange. In detail, I want to use momentum resolved EELS to measure the nanoscale fields in the optical resonances of nanoparticles more accurately and quantitatively than before, the bandgap and band structure of semiconductors and 2D materials with nanometer resolution and the bonding orientation of atoms in complex oxides. Separately, I want to develop a system to probe sub-THz spectroscopy at the nanoscale by using a sinusoidally pulsed electron beam to excite the sample with extreme spectral precision.

Researcher(s)

• Promoter: Verbeeck Johan
• Fellow: Guzzinati Giulio

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The rapid progress in materials science that enables the design of materials down to the nanoscale also demands characterization techniques able to analyze the materials down to the same scale, such as transmission electron microscopy. As Belgium's foremost electron microscopy group, among the largest in the world, EMAT is continuously contributing to the development of TEM techniques, such as high-resolution imaging, diffraction, electron tomography, and spectroscopies, with an emphasis on quantification and reproducibility, as well as employing TEM methodology at the highest level to solve real-world materials science problems.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This project builds on the proof of concept technology of a programmable phase plate for electron optics developed during an earlier POC project (2018-2019) with the aim to develop it towards a spin off company. The unique and protected technology will lead to a disruptive step in the capabilities of electron microscopy. We singled out 8 different application domains that would critically benefit from this technology, each in a different phase of development. An in-depth market study is needed to prioritize these applications in terms of which ones should be started from. We aim to raise the TRL level from 5 to 7 by mastering the technological risks in order to sell a product to a selection of early adopters and thereby start the company. This envisioned path makes optimal use of the window of opportunity in the market and can transform the knowledge developed at UA into valorisable results that will lead both to a societal and economic added value for our university and region.

Researcher(s)

• Promoter: Verbeeck Johan

Research team(s)

• Electron microscopy for materials research (EMAT)

Project website

Project type(s)

• Research Project

Abstract

For the University of Gent, high resolution HAADF-STEM images have been recorded in combination with STEM-EDX element mapping. The particles contained palladium and cobalt and did not have the expected shape.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Self-assembly of nanoparticles (NPs) offers a versatile platform for the design of novel materials with enhanced collective properties. A promising route to achieving tailored properties with NPs is to bring them together into superstructures called Supraparticles (SPs). The greatest potential for bringing forth diverse new properties comes from multicomponent SPs, in which multiple types of NPs are used in the SPs. I propose to use spherical confinement to first build SPs which I will then treat with cation exchange (CE), a powerful tool for synthesizing NPs with controlled structures. The goal is to establish a robust route to structuring multicomponent SPs in a controlled manner and enable the engineering of new SPs with optimal properties for applications ranging from catalysis to photovoltaics. A complete structural analysis of cation exchanged (CE-ed) SPs in 3D is essential as it will reveal the CE process in SPs. I will develop innovative quantitative 3D electron microscopy (EM) techniques to investigate the dynamics of the structural evolution of CE-ed SPs on the single NP level, providing insights into how to achieve optimal properties. Optimization of sample support and development of fast multimode electron tomography will make this possible by eliminate beam damage. Liquid tomography will allow me to fully understand the 3D structures of CE-ed SPs under realistic conditions. By combining in-situ heating and fast multimode electron tomography, I will decipher the mechanism of heat-induced intra- and inter- particle CE in SPs. My program will enable me to understand the interplay between NP shape, stacking and heating on the resulting SP structures. This program will be the start of a completely new research line in the fields of both colloidal science and 3D characterization. The outcome will boost the possibilities for the design and application of functional materials as well as push the limits of 3D EM techniques.

Researcher(s)

• Promoter: Bals Sara
• Fellow: Wang Da

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Although recent advances in nanotechnology have provided an excellent platform to revolutionize the domain of health, the efficient and target delivery of many potent drugs in the body still remains an important challenge due to important drawbacks either from the drug (bioavailability, toxicity, etc.) and/or from the nanocarrier (biocompatibility, reproducibility, insufficient targeting). Consequently, there is currently a real demand for drug nanocarriers able to solve these matters for the different administration routes. HeatNMof project aims to develop smart multifunctional nanocarriers of challenging antitumoral drugs based on versatile highly porous biocompatible nanometric Metal Organic Frameworks, associated with exceptional drug payloads and controlled releases, and photo- and/or magnetic inorganic nanoparticles, providing both a specific control of reactions inside living entities (i.e. heating-triggered drug release) and additional properties such as imaging (magnetic resonance, thermal or optoacoustic imaging) and/ or hyperthermia therapy. The successful development of this project, involving academic and industrial partners, will contribute to the improvement of the highly societal relevant cancer therapy. This research objective is strongly related with the prime training/networking aim of HeatNMof: to train the next generation of materials scientists in a highly interdisciplinary and intersectorial research environment, such that they can soundly address upcoming challenges concerning nanomedicine, from the development, optimization and (physicochemical and biological) characterization of inorganic and hybrid materials, as well as their interaction with living entities, with a strong focus on drug delivery platforms based on nanomaterials. HeatNMof will train the next generation of material scientists with sound expertise in nanomedicine, highly needed to bring advanced materials as proposed from the bench to society.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

In this project, we will be the first to determine structural changes at unit cell level during oxidation and reduction processes in situ in gasses and liquids with electron diffraction tomography. In situ means that the data is collected on the sample while it is still in the environment where the reaction occurred. Such oxidation and reduction processes are important in the field of energy materials, a research field with very high activity worldwide as sustainable energy is of vital importance for our whole society. Changes in structures under oxidation and reduction processes dictate ion conduction paths and reversibility, thus efficiency, capacity and lifetime of the different technologies. Such structural changes are currently followed using X-ray and neutron powder diffraction techniques, because the materials are usually only active as submicron particles. Although these techniques can uncover very important structural changes, they are often plagued by peak overlap of different phases and peak broadening due to the small crystal sizes, making the results less conclusive and leaving some structures unsolved. Using electrons will allow performing in situ single crystal experiments on the individual particles within a powder sample, due to the much stronger interaction between electrons and matter. Single crystal data has a lot of advantages over powder diffraction data for structure determination and will allow uncovering information and determining structures out of reach of in situ powder diffraction techniques. Precession electron diffraction tomography is already used for structure determination from ex situ single crystal data. Using this technique in situ, we will monitor how structures of materials change under oxygen atmosphere or reducing hydrogen atmosphere, under hydration or carbon dioxide, or under electrochemical oxidation and reduction. Our goal is to be the pioneers in using this technique of in situ PEDT and to demonstrate to the international materials science community the high value of the technique by providing missing structural information on several compounds from the field of energy materials. The compounds are selected from the fields of lithium-ion and polyanionic battery materials, solid oxide fuel cells, proton conducting fuel cells and chemical looping in order to reach a wide audience.

Researcher(s)

• Promoter: Hadermann Joke

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Adaptive optics, the technology to adapt the shape of lenses and mirrors to optimise the imaging capabilities, has sparked an avalanche of scientific discoveries in diverse areas of science that rely on light optics. Nowadays, optical waves can be dynamically programmed in terms of their phase profile, providing experimental research on exotic beam types and unprecedented control over the performance of optical instruments. Accelerated electron beams, on the other hand, as used extensively in e.g. electron microscopy, carry many similarities with light including the wave nature and the existence of (electron optical) lenses as well as a very similar mathematical description. The one part missing so far, is a generic programmable phase plate for electron waves allowing for similar flexibility as in state of the art light optics. The goal of this project is to explore the potential that a prototype generic phase plate, recently developed in my group and unique in the world, would bring to electron microscopy. Such a phase plate can dramatically increase the information obtained at a given electron dose, limiting the detrimental effect of beam damage that hinders the use of electron microscopy in e.g. life sciences or soft matter research. Specifically, it would enable the study of the structure and chirality of single molecules for e.g. drug discovery, insights in nanoplasmonic antennas for solar harvesting, improved precision in e-beam lithography and many more.

Researcher(s)

• Promoter: Verbeeck Johan

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Many materials around us show properties that depend in a sensitive way on small amounts of foreign atoms in an environment of majority atoms. Transmission electron microscopy is a very powerful method to study the atomic structure of materials down to the atomic scale, and spectroscopic methods allow to pinpoint the types of atoms present. Two spectroscopic methods, EELS and EDX, are commonly used and rely on the excitation of the atoms when interacting with a beam of accelerated electrons. Both methods however have significant shortcomings, especially when it comes to obtaining detailed information on these all-important minority atoms. In this project, we propose to make use of recent developments in detectors for electrons and X-rays that form the basis of these spectroscopic methods. We propose to collect atomic excitation events in a time resolved fashion, which allows us to select those events where both an electron and X-ray is detected at the same time. In doing so, we join the benefits of both EELS and EDX methods and dramatically improve the performance of these spectroscopic methods in cases where small amounts of atoms are present in an environment of a majority of other elements. We will test the benefits of a prototype setup on several types of materials that are relevant for society: modern engineering alloys, materials for future quantum computers and semiconductors for electronics and photovoltaic applications.

Researcher(s)

• Promoter: Verbeeck Johan

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Rechargeable Li-ion batteries are a pillar of our current technology driven society. More energy per mass unit can be stored in layered high capacity cathodes but they suffer from the voltage fade and voltage hysteresis reducing their energy efficiency. These detrimental effects mainly originate from the structural changes in the cathode material during charge and discharge. Recent developments have led to a paradigm shift, by showing that in these promising cathodes the oxygen oxidation, contributing to high capacity, is inherently linked with transition metal cation migration upon cycling. Together, they cause the voltage hysteresis and voltage fade. Gaining understanding of the complex interplay and control over both is necessary to exploit the advantages while eliminating the detrimental effects. To monitor both effects systematically and separate from the influence of the microstructure, we will synthesize new model structures with dedicated structural variations of the initial crystal structure and microstructure. We will study their structural changes upon cycling with state-of-the-art structure characterization techniques, and relate them to the electrochemical properties. This project will thus result in new viable Li-ion battery cathodes and allow the comprehensive understanding of the role of the microstructure, local structure and local valence for the stability of Li-rich layered cathodes, major candidates for future advanced rechargeable Li-ion batteries.

Researcher(s)

• Promoter: Bals Sara
• Co-promoter: Hadermann Joke
• Co-promoter: Van Aert Sandra
• Co-promoter: Verbeeck Johan

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The ARCLATH project investigates how energy, in the form of molecular hydrogen, can be stored and transported in a crystal structure, so-called clathrates. This way, a new storage and transportation system is available so renewable energy can be used where and when it is needed.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

In order to fully understand the structure-property relationship of materials, it is important to reliably quantify structure parameters such as the position of the atoms, the type of the atoms, and the number of atoms. The starting point of a quantitative analysis is the availability of a correct physics-based model depending on those structure parameters. My research focuses on quantifying these parameters from atomic resolution electron microscopy images.

Researcher(s)

• Promoter: De Backer Annick

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This project encompasses the structural characterisation of non-toxic quantum dots for advanced high intensity lighting applications, by using advanced transmission electron microscopy (TEM) techniques.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

All-solid-state lithium ion batteries (ASSBs) have the potential to become the next generation of energy storage devices because of their better safety and higher energy density, compared to conventional liquid electrolyte lithium ion batteries. Currently, the performance of ASSBs is limited by interfacial resistance at the electrode/electrolyte interfaces, due to the formation of solidelectrolyte interphases (SEIs). Whereas most SEIs are unwanted, artificial SEIs i.e. thin coatings between the electrode and the solid electrolyte, are also investigated to, oppositely, protect against the degradation of the electrode/electrolyte interface and to reduce the interfacial resistance. In this project, I will determine the crystal structure of the SEIs between LiPON and several commercially relevant cathode materials at different stages during cycling. I will do this, to my knowledge for the first time, by using electron diffraction techniques while charging and discharging a thin-film ASSB in a cell filled with inert argon gas inside a transmission electron microscope. This will prevent that the results are influenced by relaxation, electron beam damage, gas evaporation, or reactions due to air exposure. I will also study the application of artificial SEIs at the LiPON/cathode interfaces. The experimental findings will be compared with recent theoretical models that try to explain SEI formation. Measures to increase battery performance will be proposed.

Researcher(s)

• Promoter: Hadermann Joke
• Fellow: Poppe Romy

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The goal of my proposal is to develop a powerful method in order to evolve toward four-dimensional (4D=3D+time) quantification of nanostructures of arbitrary shape, size and atom type at the atomic scale. Therefore, novel quantitative measurement tools will be combined with aberration-corrected scanning transmission electron microscopy (STEM). Quantitative 3D characterisation of nanostructures can nowadays be achieved with high reliability for model-like systems with 1 type of chemical element present. Also for some heteronanostructures, a 3D visualisation at the atomic scale is possible using state-of-the-art STEM. However, high-precision quantification often involves a meticulous analysis using advanced methods. This impedes high-throughput analyses which are increasingly important for the study of dynamical processes induced by heating, under de flow of a selected gas, or by the electron beam. In this project, the initiation of real-time image simulations will be a giant leap forward for the 4D characterisation of nanomaterials. This highly challenging and innovative objective will be reached by introducing deep learning architectures into quantitative STEM. This unique approach will allow simulating images in real time using a fully physics-based description of the experimental intensities. The outcome of this project will deliver all necessary input for understanding and predicting the properties in complex nanostructures and their dynamical processes.

Researcher(s)

• Promoter: Van Aert Sandra
• Fellow: De Backer Annick

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The properties of nanomaterials are controlled by their three-dimensional (3D) atomic structure. Nowadays, quantitative methods can be used to retrieve 3D atomic structural information from two-dimensional (2D) scanning transmission electron microscopy (STEM) images of materials which can withstand high electron doses. The goal of this project is to develop quantitative methods to estimate the atomic positions, atom types, and number of atoms from 2D STEM images recorded using a low electron dose.

Researcher(s)

• Promoter: Van Aert Sandra
• Co-promoter: De Backer Annick
• Fellow: De wael Annelies

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The study of disorder has become a major aspect in the engineering of Metal Organic Frameworks (MOFs) since materials scientists recognised the strong influence of structural imperfections on MOFs functional properties. As the interest in MOFs' defect engineering grows exponentially, this practice becomes more and more precise in tailoring the type and distribution of defects. However, the structural characterisation possibilities still cannot guarantee an adequate quantitative precision. This is mainly due to the limited development of total scattering single crystal analyses on nanocrystals, which are a vast majority of the employed MOFs. My project aims to fill this gap by developing a novel method based on the use of electron diffuse scattering from Transmission Electron Microscopy analyses. The proposed method will be applied on a heterogeneous set of widely used nano-MOFs with unknown defects. This will at the same time define unambiguously their defect structures for the first time and validate the method to make it available for use in any research group. The acquired information will eventually be combined with the one achievable by bulk analyses to compensate for the limited statistical representativeness of single crystal analyses. This will allow to obtain a complete description of these materials' structure and to define general guidelines for the investigation of defects in nanomaterials by using methods available for the general use.

Researcher(s)

• Promoter: Hadermann Joke
• Fellow: Canossa Stefano

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The main objective of the TEM characterizations is to elucidate the fundamental micro/nanoscopic mechanisms controlling the deformation and fracture of bulk and small-sized metals and alloys elaborated in UCL. Ex-situ advanced TEM techniques such as aberration corrected TEM, automatic crystallographic orientation and nanostrain mapping in TEM as well as analytical TEM will be used to characterize defects and interfaces while quantified in-situ nanomechanical TEM testing will be performed in order to directly observe the plasticity mechanisms inside the microscope. TEM thin foils for the ex-situ and in-situ TEM characterizations will be prepared in EMAT.

Researcher(s)

• Promoter: Schryvers Nick

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The main objective of the TEM characterizations is to elucidate the fundamental micro/nanoscopic mechanisms controlling healing of damages in Aluminum alloys elaborated in UCLouvain. Ex-situ advanced TEM techniques such as aberration corrected TEM, automatic crystallographic orientation and nanostrain mapping in TEM as well as analytical TEM will be used to characterize defects and interfaces while quantified in-situ TEM testing will be performed in order to directly observe the mechanisms under interest inside the microscope. TEM thin foils for the ex-situ and in-situ TEM characterizations will be prepared in EMAT.

Researcher(s)

• Promoter: Schryvers Nick

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The main objective of the TEM characterizations is to elucidate the fundamental micro/nanoscopic mechanisms controlling the deformation and fracture of hybrid nanolaminated thin films provided by UCLouvain. Ex-situ advanced TEM techniques such as aberration corrected TEM, automatic crystallographic orientation and nanostrain mapping in TEM as well as analytical TEM will be used to characterize defects and interfaces while quantified in-situ nanomechanical TEM testing will be performed in order to directly observe the plasticity mechanisms inside the microscope. TEM thin foils for the ex-situ and in-situ TEM characterizations will be prepared in EMAT.

Researcher(s)

• Promoter: Schryvers Nick

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The properties of nanomaterials are essentially determined by their 3D structure. Electron tomography enables one to measure the morphology and composition of nanostructures in 3D, even at atomic resolution. Unfortunately, all these measurements are performed at room temperature and in ultra-high vacuum, which are conditions that are completely irrelevant for the use of nanoparticles in real applications! Moreover, nanoparticles often have ligands at their surface, which form the interface to the environment. These ligands are mostly neglected in imaging, although they strongly influence the growth, thermal stability and drive self-assembly. I will develop innovative and quantitative 3D characterisation tools, compatible with the fast changes of nanomaterials that occur in a realistic thermal and gaseous environment. To visualise surface ligands, I will combine direct electron detection with novel exit wave reconstruction techniques. Tracking the 3D structure of nanomaterials in a relevant environment is extremely challenging and ambitious. However, our preliminary experiments demonstrate the enormous impact. We will be able to perform a dynamic characterisation of shape changes of nanoparticles. This is important to improve thermal stability during drug delivery, sensing, data storage or hyperthermic cancer treatment. We will provide quantitative 3D measurements of the coordination numbers of the surface atoms of catalytic nanoparticles and follow the motion of individual atoms live during catalysis. By visualising surface ligands, we will understand their fundamental influence on particle shape and during self-assembly. This program will be the start of a completely new research line in the field of 3D imaging at the atomic scale. The outcome will certainly boost the design and performance of nanomaterials. This is not only of importance at a fundamental level, but is a prerequisite for the incorporation of nanomaterials in our future technology.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Self-assembly of nanoparticles (NPs) offers a versatile platform for the design of novel (meta) materials with enhanced collective properties that are distinct from the sum of the their components. A promising route to structure NPs over multiple length scales is to let the NPs assemble in spherical confinement to form Supraparticles (SPs). It is challenging to design multi-component SPs as the parameter space to achieve the optimum thermodynamics and kinetic effects is large. To tackle this challenge, we will apply cation exchange (CE) to already self-assembled SPs containing quantum dots (QDs). Multi-component SPs with different structures will be obtained, which is impossible to achieve by conventional synthetic routes. A complete analysis of resulting CE-ed SPs is essential because a thorough understanding of the structure-property connection of the SPs will enable more rational synthesis of novel structures with predefined properties. We will apply advanced Energy dispersive X-ray spectroscopy tomography to CE-ed SPs to extract positions, orientations, and elemental distributions of singe QDs in 3D. We will utilize advanced heating holder for electron tomography study heat-induced morphological and compositional- changes of the CE-ed SPs in 3D.

Researcher(s)

• Promoter: Bals Sara
• Fellow: Wang Da

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This project encompasses the development of a sample preparation protocol by focused ion beam - scanning electron microsopy (FIB-SEM) and (cryo-)ultramicrotomy. The coating of the particles is studied using scanning (SEM) and transmission (TEM) electron microscopy.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Magnetic materials are a vital part of modern society, being important components in technologies such as magnetic resonance imaging machines and hard disk drives. A common strategy to both improve existing technologies and develop new ones, is miniaturization. The most striking example being the billion-fold increase in silicon semiconductor transistor density, which fundamentally changed society since its invention in the 60ies. However, this miniaturization trend now seems to come to a slow-down as devices are shrinking to sizes where hard physical limits are setting in, and being able to image these nanoscale devices becomes ever more important. Scanning transmission electron microscopy (STEM) is a widely used imaging technique used to study such nanometre scale devices, however it does not readily provide imaging of the magnetic properties at this scale. The perovskite oxides form a materials family, which exhibits a wide range of properties including magnetism. A similar miniaturization process has been used for these materials, where making them as nanometre thick films revealed new phenomena. The most exciting being multiferroics, where an applied electric field can change the magnetic structure, and vice versa. This has attracted much interest in both making and studying these oxide materials, especially their magnetic properties, due to the great potential for new device concepts. However, due to the small sizes of these films they're often very hard to study, especially when it comes to their nanoscale magnetic structure. This action will take advantage of recently developed fast electron STEM detectors to image the nanometre scale magnetic structures of these materials directly with unprecedented resolution. Using a high-end STEM equipped with such a detector, both the magnetic and crystal structure will be studied in the same microscope. This will enable highly correlated studies of the perovskites, giving a deeper understanding of these new phenomena.

Researcher(s)

• Promoter: Verbeeck Johan
• Fellow: Nord Magnus

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Many of functional materials such as multiferroic oxides and shape memory alloys contain numerous interfaces and domains, playing key roles in their functions. Nevertheless, understanding of relations between the functions and properties of interfaces, including macroscopic morphologies, local atomic configurations, and electromagnetic states, still have been a big challenge due to difficulties in characterization of individual interfaces. In this joint research project, the aim will be to develop a new methodology to evaluate morphology, atomic structure, and electromagnetic properties of interfaces in functional materials by means of integrating electron microscopy techniques of Kyushu University and University of Antwerp.

Researcher(s)

• Promoter: Schryvers Nick

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Application of an in-house Focused Ion Beam (FIB) protocol for preparation of TEM apertures developed during the ERC-project "Vortex". These specialized apertures can be used for generation of vortex and/or Bessel beams for analysis of e.g. electromagnetic properties, strain and plasmonics.

Researcher(s)

• Promoter: Verbeeck Johan

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

ESTEEM3 is an integrating activity for electron microscopy providing access to the leading European state-of-the-art electron microscopy research infrastructures, facilitating and extending transnational access services of the most powerful atomic scale characterization techniques in advanced electron microscopy research to a wide range of academic and industrial research communities for the analysis and engineering of novel materials in physical, chemical and biological sciences. ESTEEM3 objective is to deliver more access to more users coming from a wider range of disciplines. Transnational Access to ESTEEM3 centres is obtained through a transparent, simple peer review process based on merit and scientific priorities. Optimum service to users is supported by networking and joint research activities, which address key issues such as specimen preparation, data interpretation, treatment and automation through theory and simulation, and standardization of protocols and methodologies. Innovative activities dedicated to the dissemination of expertise, education and training in cutting-edge quantitative transmission electron microscopy techniques, such as schools, advanced workshops and webinars, are offered to the European electron microscopy users from academia, research institutes and industry. Directed research programmes involving the academic and industrial partners of the consortium focus on the further methodology development in imaging and diffraction, spectroscopy, in-situ techniques and metrology, and on advancing applied research of materials related to ICT, energy, health, and transport for the benefit of European scientists and industry. Moreover, the definition of strategic roadmaps and open access data policies aims to ensure the long-term sustainability of the consortium. In all, ESTEEM3 establishes a strategic leadership in electron microscopy to guide future developments and promote electron microscopy to the widest research community at large.

Researcher(s)

• Promoter: Verbeeck Johan

Research team(s)

• Electron microscopy for materials research (EMAT)

Project website

Project type(s)

• Research Project

Abstract

The first aim of this project is to determine whether it is possible to quantify the three dimensional correlated disorder in materials using the three dimensional diffuse scattering in electron diffraction patterns. Correlated disorder is any type of deviation from an average structure that is correlated between neighbouring unit cells only. Many open questions in materials science are related to this correlated disorder. If we can use electron diffraction to refine correlated disorder, we gain access to single crystal information also for the submicron sized crystals in powder samples, which are often the only available form. We will use electron diffraction methods proven to work for Bragg scattering (sharp reflections) and combine these with algorithms from the fields of X-ray and neutron diffraction diffuse scattering. The second aim of this project is to analyze qualitatively and quantitatively the electron diffraction Bragg and diffuse scattering in lithium-ion battery materials to characterize the structural changes upon electrochemical cycling. This is important fundamental knowledge for gaining control over the degradation in lithium batteries. For this, we will quantify electron diffraction data obtained in situ in an electrochemical liquid cell. Doing this, we will not only provide new knowledge on the materials under investigation, but also introduce a new means to access a wealth of currently unavailable information on battery materials.

Researcher(s)

• Promoter: Hadermann Joke

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

PROCEED aims to develop a new hybrid perovskite material platform for next-generation light detectors, emitters and harvesters. Beyond photovoltaics, hybrid perovskites are materials with high potential for highly relevant applications such as X-ray detectors for medical diagnostic imaging and lasers for lighting and display. To make this potential effective, the chemical and structural flexibility of hybrid perovskites will be exploited to bring the material architecture to a next level of complexity with the introduction of extra functionalities. Implementation of novel hybrid perovskites of different composition and dimensionality (3D, 2D), structures (nanoplatelets, thin films, thick layers including nanocrystals), controlled morphology (crystallinity, uniformity), and their further integration in advanced device structures, will enable order-of-magnitude of improvement of the material stability together with a strong increase of the first figure-of-merit for each selected application – i.e. sensitivity for X-ray detectors, gain for laser, and power conversion efficiency for solar cells – beyond the level achievable by the respective current technologies, and with lower or similar production costs. The scope of this project requires synergy of multiple fields of science and engineering, such as chemistry, material science, processing, device fabrication and testing, demonstrators and reliability.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

In this project we provide an atomistic description by means of quantum mechanical density functional theory calculations of the defects that occur during the corrosion of UO2 to U3O8. In particular we investigate the properties of the intermediate oxide U3O7, which is the main precursor to the formation of U3O8. We investigate the influence of external factors like water and grain boundaries on the oxidation of UO2. The formation mechanisms of U3O8 are essential to understand the degradation of spent fuel under storage conditions.

Researcher(s)

• Promoter: Lamoen Dirk

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The main objective is to study the microstructure and morphology of SCC cracks of tested and industrial specimens. The aim of this study is to provide additional experimental results that could help to rationalize existing methodologies used to analyze the failure of internals. Obtained results will be analyzed in the light of the existing threshold methodology as well as on the basis of a recently proposed quasi brittle fracture model assuming an internal oxidation SCC mechanism. In this study an analysis of O-ring samples tested in the constant load experiment will be performed by utilizing the SEM and TEM. We foresee different type of analyses to be carried out: • Analysis of non-fractured irradiated O-rings on stressed and compressed areas to see whether initiation sites are present. • Analysis of the crack statistics at the outer surfaces and fracture surfaces (branching) of fractured O-rings as function of applied stress and test time (both non-irradiated and irradiated samples). • Analysis of irradiation induced defects by TEM • An energy dispersive X-ray (EDS) spectroscopy, combined with both SEM and TEM, of the same tested O-ring specimens used in the study related to cracking statistics. • Analysis of the grain boundaries of the samples by TEM, in particular oxidized grain boundaries at the crack tip. Some of these materials were retrieved from the inside of a nuclear reactor and are considered as unique test material. Out hot cell facilities and associated experimental techniques provide unique environment and possibility to perform proposed study. In addition, recent acquisition of focused ion beam (FIB) experimental setup at SCK.CEN will allow accurate sample extraction from relevant specimen regions, e.g. close to and beyond the crack tip. Microstructural analysis at the crack tip is expected to provide crucial information in order to elucidate the complex mechanism responsible for irradiation assisted stress corrosion cracking (IASCC).

Researcher(s)

• Promoter: Schryvers Nick

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The design and synthesis of metal nanoparticles (NPs) with predefined size and shape remains a major challenge in materials science. Although the growth of Au NPs is mature, synthetic procedures have evolved largely empirically so far. Obtaining full control over the synthesis of Au NPs is of key importance toward their efficient applicability in e.g. photothermal therapy and plasmonic sensing. However, in order to optimize the synthesis protocols and obtain NPs with specific properties, a detailed quantitative structural characterization of the products during the different growth stages by advanced transmission electron microscopy (TEM) is needed. The aim of this project is to optimize TEM techniques and to develop novel three-dimensional (3D) characterization tools, adequate to elucidate different aspects in the growth of Au NPs that still remain unclear. These novel methodologies will allow me to characterize Au NPs at different growth stages, which will yield the necessary insights to gain control over both the growth of Au seeds as well as the Au NPs. A challenging and ambitious goal in this project will be to realize high throughput 3D studies to perform a statistically relevant analysis concerning the size and shape of NPs. This project will have a major impact on the synthesis of metal NPs. The outcome of our experiments will enable one to optimize the synthesis towards highly monodisperse NPs, which will lead to a more effective use in biomedical applications.

Researcher(s)

• Promoter: Bals Sara
• Fellow: Bladt Eva

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This agreement allows Mr. Chao Deng from the Chonqing University, China to join in TEM experiments at the EMAT laboratory of the University of Antwerp, Belgium, on ACOM-TEM making use of the ASTAR & Topspin equipment. In total 5 training sessions of half a day will be offered during a 4 week period (from 21.07.2018 to 22.09.2018), including demonstration sessions, a hands-on session and a session on data treatment. The training will be carried out by trained EMAT personnel at the EMAT laboratory. The TEM experiments will be conducted on the Tecnai microscope and all necessary support will be provided by designated members of the EMAT team. Sessions on TEM instruments will be designated following regular EMAT rules.

Researcher(s)

• Promoter: Schryvers Nick

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Metal nanoparticles (NPs) are intriguing systems due to their efficient interactions with light stemming from localized surface plasmon resonances (LSPRs), a phenomenon which is exploited in many applications in fields ranging from physics to biology and medicine. In particular, anisotropic shapes are interesting because of strong electromagnetic field enhancements at corners and tips. Next to monometallic NPs, bimetallic NPs offer an additional way of tuning the functionality and plasmon resonance and are advantageous for applications such as photocatalysis. Understanding the delicate interplay between particle morphology, composition and optical properties is of utmost importance in optimizing particle design for the desired applications. While optical properties of metal NPs have been related to structure by using surface imaging techniques like scanning electron microscopy (SEM), a complete connection to the atomically resolved 3D structure has never been accomplished. Here, I propose to investigate the correlation of the full atomic morphology (including composition) and optical properties of (bi)metallic NPs by single-particle optical experiments and electron microscopy techniques such as atomically resolved electron tomography. I will furthermore study the correspondence and differences between electronically-excited and optically-excited plasmon modes. The key aspect of the proposed research is that the correlated measurements will be performed, for the first time, on the same particle allowing for a full understanding of how the morphology and composition of a metal NP is related to its optical properties.

Researcher(s)

• Promoter: Bals Sara
• Fellow: Albrecht Wiebke

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Understanding nanostructures down to the atomic level is the key to optimise the design of advanced materials with revolutionary novel properties. This requires characterisation methods enabling one to quantify atomic structures with high precision. The strong interaction of accelerated electrons with matter makes that transmission electron microscopy is one of the most powerful techniques for this purpose. However, beam damage, induced by the high energy electrons, strongly hampers a detailed interpretation. To overcome this problem, electron microscopy will be ushered in a new era of non-destructive picometer metrology. This is an extremely challenging goal in modern technology because of the increasing complexity of nanostructures and the role of light elements such as lithium or hydrogen. Non-destructive picometer metrology will allow us to answer the question: what is the position, composition and bonding of every single atom in a nanomaterial even for light elements? There has been significant progress with electron microscopy to study beam-hard materials. Yet, major problems exist for radiation-sensitive nanostructures because of the lack of physics-based models, detailed statistical analyses, and optimal design of experiments in a self-consistent computational framework. In this project, novel data-driven methods will be combined with the latest experimental capabilities to locate and identify atoms, to detect light elements, to determine the three-dimensional ordering, and to measure the oxidation state from single low-dose recordings. The required electron dose is envisaged to be four orders of magnitude lower than what is nowadays used. In this manner, beam damage will be drastically reduced or even be ruled out completely. The results of this programme will enable precise characterisation of nanostructures in their native state; a prerequisite for understanding their properties. Clearly this is important for the design of a broad range of nanomaterials.

Researcher(s)

• Promoter: Van Aert Sandra

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Processes in energy applications and catalysis as well as biological processes become increasingly important as society's focus shifts to sustainable resources and technology. A thorough understanding of these processes needs their detailed observation at a nano or atomic scale. Transmission electron microscopy (TEM) is the optimal tool for this, but in its conventional form it requires the study object to be placed in ultrahigh vacuum, which makes most processes impossible. Using environmental TEM holders, the objects can be placed in a gas/vapour or liquid environment within the microscope, enabling the real time imaging, spectroscopic and diffraction analysis of the ongoing processes. This infrastructure will enable different research groups within the University of Antwerp to perform a wide range of novel research experiments involving the knowledge on processes and interactions, including among others the growth and evolution of biological matter, interaction of solids with gasses/vapours or liquid for catalysis, processes occurring upon charging and discharging rechargeable batteries, the nucleation and growth of nanoparticles and the detailed elucidation of intracellular pathways in biological processes relevant for future drug delivery therapies and treatments.

Researcher(s)

• Promoter: Hadermann Joke
• Co-promoter: Bals Sara
• Co-promoter: Breugelmans Tom
• Co-promoter: Meynen Vera
• Co-promoter: Sijbers Jan
• Co-promoter: Verbruggen Sammy

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This project aims at developing a prototype of a programmable electrostatic phase plate that allows the user to freely change the phase of electron waves. The target of this POC project is the realization of a tunable easy-to-use 5x5-pixel prototype that will demonstrate the potential of adaptive optics in electron microscopy. Its realization will be based on lithographic technology to allow for future upscaling. It is expected that such a phase plate can dramatically increase the information obtained at a given electron dose, limiting the detrimental effects of beam damage that currently hinders the use of electron microscopy in e.g. life sciences. As such, it has the potential to disrupt the electron microscopy market with novel applications while at the same time reducing cost and complexity and increasing the potential for fully automated instruments.

Researcher(s)

• Promoter: Verbeeck Johan

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Modern society relies on materials which exhibits or are influenced by magnetic fields, such as functional materials used in electronic devices. In the last decades the performance of such devices have been greatly improved though miniaturization, however at some point the size of the these devices cannot be reduced further due to physical limits. To continue the advances in electronics, new materials with novel properties must be utilized. This requires a deep insight into the coupling between structural and functional properties, with nanometre resolution. An understanding of how the magnetic microstructure at the nanoscale is affected by the atomic and electronic structure of materials will help researchers in the design of functional materials with tailored-made properties. The hypothesis of this proposal is that "Magnetic fields in functional materials can be characterized at nanometre length scales by using scanning transmission electron microscopy combined with fast pixelated detectors. This enables correlated characterization of both functional and structural properties and improved understanding of materials." With the recent development of fast pixelated electron detectors, the whole electron beam in a scanning transmission electron microscope (STEM) can be imaged. This enables imaging of magnetic fields in materials using differential phase contrast (DPC), and coupled with an aberration corrected microscope this can be done at an unprecedented resolution of 1 nm. Perovskite oxide heterostructures are receiving great interest due to the many ways magnetic properties can be altered through structure engineering. The goals of this proposal is to extend the DPC method to imaging of static and dynamic magnetic properties of such materials with nanometre resolution. Adjoined with conventional high quality STEM data of the atomic and orbital structure of the materials, our understanding of structure-function coupling in perovskite thin films will be improved.

Researcher(s)

• Promoter: Verbeeck Johan
• Fellow: Nord Magnus

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Adaptive optics, the technology to dynamically program the phase of optical waves has sparked an avalanche of scientific discoveries and innovations in light optics applications. Nowadays, the phase of optical waves can be dynamically programmed providing research on exotic optical beams and unprecedented control over the performance of optical instruments. Although electron waves carry many similarities in comparison to their optical counterparts, a generic programmable phase plate for electrons is still missing. This project aims at developing a prototype of a programmable electrostatic phase plate that allows the user to freely change the phase of electron waves and demonstrate it to potential licensees for further upscaling and introduction to the market. The target of this POC project is the realization of a tunable easy-to-use 5x5-pixel prototype that will demonstrate the potential of adaptive optics in electron microscopy. Its realization will be based on lithographic technology to allow for future upscaling. It is expected that such a phase plate can dramatically increase the information obtained at a given electron dose, limiting the detrimental effects of beam damage that currently hinders the use of electron microscopy in e.g. life sciences. As such, it has the potential to disrupt the electron microscopy market with novel applications while at the same time reducing cost and complexity and increasing the potential for fully automated instruments.

Researcher(s)

• Promoter: Verbeeck Johan

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The overarching goal of MUMMERING is to create a research tool that encompasses the wealth of new 3D imaging modalities that are surging forward for applications in materials engineering, and to create a doctoral programme that trains 15 early stage researchers (ESRs) in this tool. This is urgently needed to prevent that massive amounts of valuable tomography data ends on a virtual scrapheap. The challenge of handling and analysing terabytes of3D data is already limiting the level of scientific insight that is extracted from many data sets. With faster acquisition times and multidimensional modali-ties, these challenges will soon scale to the petabyte regime. To meet this challenge, we will create an open access, open source platform that transparently and efficiently handles the complete workflow from data acquisition, over reconstruction and segmentation to physical modelling, including temporal models, i.e. 3D "movies". We consider it essential to reach this final step without compromising scientific standards if 3D imaging is to become a pervasive research tool in the visions for Industry 4.0. The 15 ESRs will be enrolled in an intensive network-wide doctoral training programme that covers all aspects of 3D imaging and will benefit from a varied track of intersectoral secondments that will challenge and broaden their scope and approach to research.

Researcher(s)

• Promoter: Bals Sara
• Co-promoter: De Beenhouwer Jan
• Co-promoter: Sijbers Jan

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The aim of this project is to retrieve the 3D atomic structure of nanocrystals from transmission electron microscopy (TEM) images acquired along a single viewing direction. This goal is extremely challenging but can be considered as a major breakthrough to investigate materials that degrade or deform during the acquisition of images along different viewing directions, such as in electron tomography. So far, 3D imaging at the atomic scale was only carried out for model-like systems, which are relatively stable under the electron beam. We envisage the combination of aberration corrected TEM with advanced statistical techniques and theoretical modelling as a groundbreaking new approach to go beyond conventional electron tomography and to perform 3D characterization at the atomic scale in a dose and time efficient manner. Our novel methodology will enable us to characterize functional materials that are very sensitive to the electron beam such as organic perovskites, colloidal semiconductors or battery materials, but will also open up the possibility to investigate the dynamics of nanoparticles during in situ measurements. Moreover, we will be able to drastically improve the throughput of electron tomography experiments, which is a prerequisite when trying to connect the structure to the functional properties. We therefore expect that the outcome of this project will deliver all necessary input to predicting properties and may even guide the synthesis of new nanostructures.

Researcher(s)

• Promoter: Van Aert Sandra
• Co-promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The goal of this project is to develop and apply smart strategies, which are dedicated to characterise beam-sensitive nanostructures using quantitative scanning transmission electron microscopy imaging. This will allow one to use a minimum electron dose to detect single atoms, to determine their atom types and to precisely measure positions of atoms. In this manner, beam damage will be drastically reduced or will even be ruled out completely.

Researcher(s)

• Promoter: Van Aert Sandra
• Co-promoter: Verbeeck Johan

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This project aims to develop a new quantum dot (QD) technology based on III-V elements, on the one hand to improve the color reproduction and reduce the energy consumption of screens, and on the other to broaden the application possibilities to light sources with a custom spectrum. For this, a switch will be made from a remote phosphor to an on-chip configuration, optimizing the performance, stability, cost and composition of the QDs.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The occurrence of two or more crystal structures for a given molecule, a phenomenon which is called polymorphism, is ubiquitous to various classes of synthetic and natural compounds. Examples of polymorphism are known in numerous application fields, such as food, explosives, pigments, semiconductors, fertilizers, and pharmaceutical drugs. Different crystal structures, so-called polymorphs, of the same compound exhibit sometimes very different physical properties, chemical reactivity, and biological functions. For instance, the polymorphs might differ in solubility ruining the pharmaceutical effect of one or more of the polymorphs. Understanding and controlling polymorphism is therefore very important. Simple questions, such as "How many polymorphs has a given compound?" or "What drives polymorph selection?", remain unanswered yet. In this scientific context, scientists have started to explore the occurrence of substrate-induced polymorphism, i.e. the formation of polymorphs that exist only in the vicinity of solid substrates. In particular, 2Dto3D has the ambition to elucidate how positional and orientational order of molecules propagate from the substrate to the upper crystal layers. In this manner, 2Dto3D will gain a fundamental understanding of polymorphism at the interface with solid substrates.

Researcher(s)

• Promoter: Van Aert Sandra

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The aim of this project is to realize a major breakthrough in the quantitative analysis of imaging and analytical techniques in scanning transmission electron microscopy (STEM). Therefore, we will exploit the physics-based description of the fundamental processes of electron scattering and combine this with a thorough multivariate statistical analysis of the recorded signals. In this manner, we will be able to identify the chemical nature of all individual atoms in three dimensions (3D). So far, imaging and analytical signals have been analyzed separately in STEM. Although analytical techniques are in principle well suited because of their elemental specificity, they have a much lower signal to noise ratio as compared to imaging techniques. We foresee that our multivariate method, in which new physics-based models are incorporated to describe the electron-object interaction, enables us to achieve element-specific atom counting at a local scale and to determine even the ordering of the atoms along the viewing direction. Furthermore, our approach will be optimized to reach high elemental measurement precision for a minimum incoming electron dose. This novel dose-efficient quantitative methodology will clearly usher electron microscopy in a new era of 3D element-specific metrology at the atomic scale. This will exactly provide the input needed to understand the unique link between a material's structure and its properties in both materials and in life sciences.

Researcher(s)

• Promoter: Van Aert Sandra

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

In this project, we propose a fast, high-resolution non-linear optical method for the ex-situ and potentially upgradable to in-situ quality control of as-grown GRMs and their heterostructures. Polarization resolved Second Harmonic Generation (PSHG) imaging microscopy will reveal detailed information of the crystal orientation, thickness inhomogeneities and nanoscale defects. Pixel-by-pixel information of the atomic structure of 2D nanosheets will be extracted from PSHG data with a spatial resolution of ~50 nm in two measuring modes: First, the number of atomic layers for each pixel will be precisely estimated by imaging the SHG intensity. Secondly, the polarization of the pixel-by-pixel SHG signal will reveal high-resolution details of the crystallographic axis orientation. Preliminary results show that defects of the crystal structure create a sharp contrast in the PSHG image. To further analyze the experimental findings, a theoretical model will be developed to accurately predict and explain the PSHG data. The interpretation of the PSHG signal by the theoretical predictions will be utilized as a "second order filter" which will further enhance the optical contrast attained. Due to the small dimensions of the pixel (~50nm) compared to the diameter of the excited volume (~500nm), the extracted optical information goes beyond the diffraction limit. This technique is being developed at the Foundation for Research and Technology- Hellas (FORTH). Towards the accurate validation and quantitative evaluation of the PSHG observations, the crystallographic orientation, specimen thickness, strain and doping/impurity levels, stacking sequence and twist, chemical composition, electric fields and charge densities will be probed on the same samples, via atomic-resolution scanning transmission electron microscopy (STEM) imaging at the Electron Microscopy for Materials Science group of the University of Antwerp (UA) and via high resolution Raman spectroscopy at the Graphene Centre (CGC) of UCAM. The CVD test-case samples will be provided by the CGC and the AIXTRON company. This project introduces for the first time an all-optical, fast and high-throughput, high-resolution, non-invasive, non- linear optical technique for the evaluation of the crystal quality of as-grown GRMs and their heterostructures. This technique can be readily upgradable for the in-situ monitoring of the 2D crystals' quality during growth. We envizage that the results obtained will have significant impact in the field of GRMs' and will be proved useful towards the development of defect-free GRMs with excellent optoelectronic properties.

Researcher(s)

• Promoter: Verbeeck Johan

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Small (submicron) metal particles interact with light in a peculiar way. Their optical properties (i.e. the colours of light they absorb or reflect) are determined by their size and shape, like the harmonics that define the sound of an organ pipe. The "harmonics" of a metal particle are called surface plasmon resonances (SPR). If SPRs can be correctly understood and harnessed, they offer the possibility to manipulate light as effectively as is done now with radio waves, allowing to produce (among others) better photovoltaics and LEDs, better chemical sensors, and integrated optical devices of much smaller size. An instrument often used to study SPRs is the transmission electron microscope (TEM). TEMs allow to observe phenomena at the nanoscale by passing a beam of high energy electrons through a sample and can achieve atomic scale resolution. The TEM is of great use to study metal particles: besides visualising their shape and structure, it allows to study the electromagnetic fields related to the SPRs. However, while this allows to visualise the harmonics, it doesn't provide all information about them. Using conventional methods, we only obtain a time-averaged view of their amplitude. With this project we want study an entirely new setup that we have recently demonstrated. It is based on altering the "quantum wave function" of a TEM's electron beam to selectively detect SPRs of a chosen shape and symmetry, helping determine their exact properties.

Researcher(s)

• Promoter: Verbeeck Johan
• Fellow: Guzzinati Giulio

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The properties of nanomaterials are controlled by their three-dimensional (3D) atomic structure. Nowadays, quantitative methods can be used to retrieve 3D atomic structural information from two-dimensional (2D) scanning transmission electron microscopy (STEM) images of materials which can withstand high electron doses. The goal of this project is to develop quantitative methods to estimate the atomic positions, atom types, and number of atoms from 2D STEM images recorded using a low electron dose.

Researcher(s)

• Promoter: Van Aert Sandra
• Co-promoter: De Backer Annick
• Fellow: De wael Annelies

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The Francqui Foundation awards a Francqui Professorships at a Belgian Universities for a period of three years. The position is intended for young promising candidates, whose research is novel and exceptional and whose field of research belongs to an important and current scientific area. This position allows the mandate holder to fully dedicate themselves to their research.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This project represents a formal research agreement between UA and on the other hand the client. UA provides the client research results mentioned in the title of the project under the conditions as stipulated in this contract.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

EUSMI will provide the community of European soft-matter researchers with an open-access infrastructure as a platform to support and extend their research, covering characterization, synthesis, and modeling. Where ESMI has set the standard for the past five years, EUSMI will significantly go beyond. EUSMI will enhance the European competitiveness in soft-matter research and innovation through the integration and the extension of the scope of existing specialized infrastructures. A full suite of coherent key infrastructures and the corresponding expertise from 15 toplevel institutions are combined within EUSMI, which will become accessible to a broad community of researchers operating at different levels of the value chain, including SMEs and applied research. Access is offered to infrastructures covering the full chain of functional soft-matter material research, ranging from advanced material characterization by a full suite of specialized experimental installations, including large-scale facilities, chemical synthesis of a full set of soft-matter materials, upscaling of laboratory synthesis, to modeling by high-performance supercomputing. The existing infrastructure will be continuously improved by JRA to allow users to conduct research always employing the most advanced techniques and methods.. In addition, an ambitious networking programme will ensure efficient dissemination and communication, as well as continued education of established researchers and training of an emerging generation of scientist. This approach will drive academic research and innovation in soft nanotechnology by providing a multidisciplinary set of essential research capabilities and expertise to guide users, developing the next generation of techniques and instruments to synthesize, characterize, and numerically simulate novel soft matter materials and contributing to the creation of a broad knowledge basis.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This project represents a formal research agreement between UA and on the other hand the client. UA provides the client research results mentioned in the title of the project under the conditions as stipulated in this contract.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This project represents a formal research agreement between UA and on the other hand the client. UA provides the client research results mentioned in the title of the project under the conditions as stipulated in this contract.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This project represents a formal research agreement between UA and on the other hand the client. UA provides the client research results mentioned in the title of the project under the conditions as stipulated in this contract.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This project represents a formal research agreement between UAntwerpen and on the other hand the client. UAntwerpen provides the client research results mentioned in the title of the project under the conditions as stipulated in this contract.

Researcher(s)

• Promoter: Schryvers Nick

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Electron tomography has evolved into a powerful technique to study the three-dimensional (3D) structure of functional nanomaterials. However, a major drawback is the total run time that is required to obtain the necessary 2D projection images, to align them and to compute the final 3D reconstruction. Since several hours are required to study a single nanoparticle, it is impossible to obtain a large set of measurements, required to connect the structure of functional nanomaterials to their properties. The latter is of crucial importance to observe the design of nanostructures with defined functionalities and the incorporation of such structures in future nanotechnology. Here, I will reduce the run time of electron tomography by a factor of 100 using a combination of novel acquisition procedures and dedicated 3D reconstruction algorithms. By applying highthroughput electron tomography, changes in the (surface) structure of catalytic nanoparticles or battery materials can be determined. In addition, the reduced acquisition time and electron dose will allow the 3D investigation of organic materials, zeolites or metalorganic frameworks. Since quasi real-time 3D imaging with the electron microscope will be possible within a few minutes, 3D experiments can be performed in a much more efficient manner to even monitor morphology changes as a function of heating. We therefore consider this project as the next (r)evolution in the field of electron tomography.

Researcher(s)

• Promoter: Bals Sara
• Fellow: Vanrompay Hans

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Electron tomography has evolved into a state-of-the-art technique to investigate the 3 dimensional structure of nanomaterials, also at the atomic scale. However, new developments in the field of nanotechnology drive the need for even more advanced quantitative characterization techniques in 3 dimensions that can be applied to complex (hetero-)nanostructures. Here, we will focus on hetero-metallic particles with electrocatalytic applications and hard-soft core-shell structures that are of interest in the field of photocatalysis. Although catalytic hetero-nanoparticles yield improved properties in comparison to their parent compounds, the underlying reasons for this optimized behaviour are still debated. Therefore, innovative 3 dimensional electron microscopy techniques are required to understand the connection between the structure, composition and catalytic properties. The combination of advanced aberration corrected electron microscopy and novel 3 dimensional reconstruction algorithms is envisaged as a groundbreaking new approach to quantify the structure AND the composition for any given nanomaterial. By combining these innovative experiments with activity and stability tests under relevant conditions we will be able to solve fundamental questions, which are of importance for both electro- and photocatalysis. Through these insights, we aim to boost the activity of catalytic nanostructures and we envisage that the outcome of our project will have major impact. For example, a fundamental understanding of the plasmonic behaviour will greatly improve the photocatalytic performance in sunlight and therefore lies at the base of better air purification technology. Our project will also enable a founded selection of catalysts in order to proceed towards an industrially applicable reaction such as the reduction of CO2 or the Oxidation Reduction Reaction.

Researcher(s)

• Promoter: Bals Sara
• Co-promoter: Breugelmans Tom
• Co-promoter: Lenaerts Silvia

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Transmission electron microscopy (TEM) has provided scientists with a view on the atomic structure of materials for many decades. As instruments improved dramatically, the damage incurred by bombarding the material with electrons has become a major obstacle in the quest for more information from ever smaller nanomaterials. In short, the material rather than the microscope has become the limiting factor to further progress. In this project we propose to apply recent insights from the field of data compression to overcome this hurdle. In essence, we will develop the instrumentation for the recording of a subset of a microscopy image while still being able to reconstruct the whole image. We use the fact that images, unlike random signals, possess a level of predictability. The reason this works is the same as why holiday pictures can be compressed for storage without losing their information content. The difference between compression algorithms and this so-called compressed sensing approach is that rather than storage space reduction, we gain a reduction in the electron dose needed to obtain an image, reducing the damage that is blocking further progress in TEM. The project builds on the recent implementation of a prototype and will explore the benefits of this approach from both a theoretical and experimental point of view with the aim to demonstrate a significant improvement in the performance of TEM on materials that previously were damaged before an image could be taken.

Researcher(s)

• Promoter: Verbeeck Johan

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Extensive research has recently been focused on the controllable synthesis of Lanthanide (Ln3+) doped nanomaterials with well-defined size and morphology because of their possible applications in lighting, displays, optoelectronics, solar energy, bio-imaging and photodynamic therapy. However, to optimize the properties and to incorporate these materials in actual devices, a fundamental understanding of the composition-structure-property relation is required. Transmission electron microscopy (TEM) is an excellent technique to investigate nanomaterials, but conventional TEM images are only two-dimensional (2D) projections of three-dimensional(3D) objects. In this project, a complete 3D characterization of Ln3+ doped nanomaterials down to the atomic scale will be provided through the combination of advanced TEM and novel 3D reconstruction algorithms. We will determine the 3D location and local environment of activators and sensitizers in host (core-shell) nanoparticles. Also, strain, intermixing and defects at the different interfaces of core-shell particles will be studied. Furthermore, the mobility of the activators and sensitizers at different temperatures will be monitored in 3D by in situ electron tomography. My project will have important impact since a thorough understanding of the composition-structure-property relation will enable the synthesis of nanomaterials with improved properties and the design of nanostructures with novel functionalities.

Researcher(s)

• Promoter: Bals Sara
• Fellow: Zhang Yang

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This project represents a formal research agreement between UAntwerpen and on the other hand the client. UAntwerpen provides the client research results mentioned in the title of the project under the conditions as stipulated in this contract.

Researcher(s)

• Promoter: Schryvers Nick

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Nowadays Li-ion batteries are the dominant technology for portable electronics and automotive applications. This project aims at further development of the new cathode materials for rechargeable batteries, including Li and Na batteries. It involves collaboration between EMAT and College de France (Paris). The group of prof. J.-M. Tarascon at College de France is specialized in synthesis and electrochemical characterization of a wide variety of novel cathode materials for rechargeable batteries. Their structural transformations upon charge/discharge processes cannot be always comprehensively understood using only bulk diffraction methods (X-ray/neutron), hence advanced transmission electron microscopy is often required. EMAT provides in depth characterization of the materials down to the atomic level using a variety TEM method, including electron diffraction methods and imaging techniques (HAADF- and ABF-STEM) that are often combined with chemical analysis using spectroscopy (STEM-EDX and STEM-EELS). As an outcome, the structure, composition and valence state of cathode materials can be directly visualized at different charge/discharge states, allowing for further development of new battery technologies.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Nano assemblies are two- or three-dimensional (3D) collections of nanoparticles. The properties of the assemblies are determined by the number of particles, their position, shape and chemical nature as well as the bonding between them. If we are able to determine these parameters in 3D, we will be able to provide the necessary input for predicting the properties and we can guide the synthesis and development of new assemblies or superstructures. The aim of this project is therefore to provide a complete 3D characterization of complex assemblies down to the atomic scale. We will reach this goal by combining advanced electron microscopy and novel 3D reconstruction algorithms. So far, 3D imaging of nano assemblies was performed for relatively small, model-like systems, consisting of spherical nanoparticles. Here, we will perform 3D measurements of larger and more complex assemblies consisting of anisotropic particles as well as binary systems in which the particles may have different compositions or sizes. Through aberration corrected TEM, we will also investigate the driving forces behind self assembly or oriented attachment at the atomic level. This project will have major impact for a broad range of applications such as drug delivery, magnetic recording or surface enhanced raman scattering. Once the connection between structure and properties is understood, the synthesis of complex assemblies can be optimized and the development of novel materials will be triggered.

Researcher(s)

• Promoter: Bals Sara
• Fellow: Altantzis Thomas

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The goal of my proposal is to develop and design a powerful method to reconstruct 3D nanostructures on the atomic scale from single 2D STEM images. Determining the full 3D structure of heterogeneous structures will allow the identification of coreshell structures, impurities and other defect structures. This is highly desirable to understand and adequately tune functional properties. In comparison to other approaches aiming at atomic scale 3D reconstruction techniques, the proposed method relies on a simultaneous acquisition of 2D images each carrying specific information concerning the number and depth location of all atoms present. This so far unique approach of retrieving the 3D atomic structure will considerably reduce beam damage and will even enable me to introduce the fourth dimension of time in electron microscopy. In this way, it becomes possible to reveal atomic scale dynamics allowing, for example, the observation of diffusion processes and the determination of different equilibrium geometries of atomic clusters.

Researcher(s)

• Promoter: Van Aert Sandra
• Fellow: van den Bos Karel

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This project represents a formal research agreement between UAntwerpen and on the other hand the client. UAntwerpen provides the client research results mentioned in the title of the project under the conditions as stipulated in this contract.

Researcher(s)

• Promoter: Schryvers Nick

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Electron tomography has evolved into a powerful technique to study the three-dimensional (3D) structure of nanomaterials. However, a major drawback is the total run time that is required to obtain the necessary 2D projection images, to align them and to compute the final 3D reconstruction. Since more than 3 hours are required to study a single nanoparticle in 3D, it is impossible to obtain a large set of measurements, required to connect the structure of nanomaterials to their properties. Also the 3D study of electron beam sensitive materials and realtime 3D studies are hampered. Here, I will reduce the run time of electron tomography by a factor of 100. I will reach this goal by combining novel acquisition procedures with dedicated 3D reconstruction algorithms. This will enable us to perform a whole new range of experiments. For example, by applying highthroughput electron tomography, changes in the (surface) structure of catalytic nanoparticles before and after cycling can be quantified. The reduced acquisition time and electron dose will allow the 3D investigation of zeolites or metalorganic frameworks. Since quasi real-time 3D imaging at the electron microscope will be possible with a temporal resolution of a few minutes, 3D experiments can be performed in a much more efficient manner and morphology changes as a function of heating can be investigated. We therefore consider this project as the next (r)evolution in the field of electron tomography.

Researcher(s)

• Promoter: Bals Sara
• Co-promoter: Goris Bart
• Fellow: Vanrompay Hans

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This project represents a formal research agreement between UA and on the other hand the client. UA provides the client research results mentioned in the title of the project under the conditions as stipulated in this contract.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Modern materials are made to perform a certain task very well at a low (energy) cost of production. This drive towards more efficient materials has shifted the attention from making e.g. the strongest material to making a sufficiently strong material at an acceptable use of natural resources. Combining this trend in materials science with the nano revolution where properties of materials depend increasingly on their structure at the nanoscale, requires scientific instruments that study these so-called soft materials on the nanoscale. Typically, this is a task for transmission electron microscopy (TEM) offering a look inside materials down to the atomic structure. A drawback of TEM however is that this process can destroy soft materials while viewing, making the analysis unreliable or impossible. In order to overcome this issue, we propose to acquire a so-called direct electron detector which efficiently detects every electron that interacts with a given material reducing the required electron dose by up to a factor of 100. This considerably shifts the field of applicability of TEM into the range of soft materials allowing us to resolve their structure down to the atomic level.

Researcher(s)

• Promoter: Verbeeck Johan
• Co-promoter: Breugelmans Tom
• Co-promoter: Cool Pegie
• Co-promoter: Lenaerts Silvia

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Nanostructure materials are found in many different forms of advanced materials. The properties of these materials strongly depend on their nanostructural features and dedicated characterization tools providing nanostatistical data are indispensable for further development of these novel materials. The present project relies on the use of advanced in-situ transmission electron microscopy (TEM) techniques coupled with the automated crystallographic orientation mapping in TEM (ACOM-TEM) approach for the investigation of the elementary deformation mechanisms and mechanical properties in the nanocrystalline Ni films. The final goal is to follow and quantify the behavior of the nanograins, grain boundaries (GBs) and internal defects during in-situ tensile experiments combined with ACOM-TEM technique. As a result we will obtain stress-strain curves for various sample size and strain rate together with a complete description of the evolution of the nanostructure features (grain size, texture, GB character, twin density, dislocation density, nanostrain mapping, etc.) until fracture. These results will provide global information on the contribution of GBs processes, twinning, texture evolution due to dislocations and strain accommodation at GBs or triple junctions. The nucleation and propagation of cracks and their interaction with GBs and twin boundaries will be also investigated. This information is of interest to a broad range of scientists including physicists, engineers and materials scientists interested in the effects of the defect mechanisms at the nanoscale controlling deformation mechanisms in nanostructured systems.

Researcher(s)

• Promoter: Amin-Ahmadi Behnam

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Perovskite based materials can be tailored to exhibit a host of physical properties, ranging from ferroelectricity and ferromagnetism, to superconductivity and ion conductivity. Any success in synthesizing new perovskite-based materials always opens up opportunities for attempting to improve the properties available in the already known perovskites. During this Ph.D., different perovskite compounds Ln2−xMxMn2-yFeyO6-δ have been made, specifically in a search for new multiferroic materials. The materials studied in this project are: La1-xAxSrMn2O5+δ (with A =Ag and Li), LaBaMnFeO6-δ, LaBaMnFe0.5Zn0.5O6-δ, LaBaMnFe0.5Ti0.5O6-δ, LaBa0.5Ag0.5MnFeO6-δ and LaBa0.5Na0.5MnFeO6-δ, LaBaFe2O6-δ, LaBaFeTiO6-δ. However, after all properties have been measured, the compounds show either semiconductivity or conductivity, depending on the sample, next to a ferromagnetic transition, but no multiferroicity. To provide valuable knowledge for future searches for multiferroics, the Ph.D. study needs to be completed with the explanation why certain properties or present or absent. For this, we need to know the structures of the compounds, since the structure dictates the properties. However, the different techniques used so far all point to different structures, Mössbauer shows oxygen-vacancy order, X-ray diffraction shows disordered but undistorted perovskite and electron diffraction shows there has to be either some form of order or some kind of distortion. Therefore, the last step of this Ph.D. study is to explain these apparent contradictions (size effects ? defect structure ? ... ?) and solve the structure of the compounds, to be able to explain the properties. This last stage will be completed using the transmission electron microscopy facilities and crystallographic expertise present at the University of Antwerp.

Researcher(s)

• Promoter: Hadermann Joke
• Fellow: Ben Hafsia Ahmed

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

In Flanders, different research groups are active in the field of quantitative imaging using statistical parameter estimation theory. These groups represent a wide range of disciplines including electron microscopy, magnetic resonance imaging, astrophysics, infra-red spectroscopy, X-ray and positron emission tomography. A common goal is to determine unknown parameters, which characterize the object under study, as precisely as possible from experimental images or spectra. The partners involved use the know-how and methods that are specific to their particular application. However, these methods are widely applicable and can be used for a broad range of problems. With the establishment of this network, the expertise of several research groups are combined and aims to stimulate new scientific collaborations and to facilitate the exchange of knowledge on various techniques.

Researcher(s)

• Promoter: Van Aert Sandra

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Over the past years, the complexity of nanosystems has increased tremendously. As a consequence, it is no longer sufficient to only characterise their structure and composition; electronic properties like valency and bonding must also be determined in parallel. This type of information can be retrieved using electron energy loss spectroscopy (EELS) at high energy resolution in a transmission electron microscope (TEM). Unfortunately, conventional TEM data remains a 2D projection of a 3D object. Therefore, the main goal of this project is to gain quantitative 3D information concerning the composition, structure and electronic properties of a wide range of nanomaterials by expanding EELS from 2D to 3D. The combination of advanced aberration corrected TEM and novel 3D reconstruction algorithms is envisioned as a ground-breaking new approach to quantify properties like valency, chemical composition, oxygen coordination, bond lengths, etc. in 3D. These experiments will clearly lead to unique insights that may even trigger the design and synthesis of nanomaterials with novel functionalities. We envisage that we will be able to understand the relationship between the 3D surface structure and catalytic functionalities and investigate the positioning of dopants in semiconductor nanocrystals and nanodiamonds. The combination of materials science, electron tomography and high resolution EELS provided here is unique and will enable us to answer fundamental questions in materials science.

Researcher(s)

• Promoter: Bals Sara
• Co-promoter: Batenburg Joost
• Co-promoter: Goris Bart
• Co-promoter: Turner Stuart

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The performance of Li-ion batteries is still far below the threshold for automotive and grid applications. This largely depends on the cathode. The commercially most developed cathode is LiCoO2, but there is a better alternative in LiNixMnxCo1-2xO2(NMC). However, even the best NMC still suffers poor electrode kinetics and large voltage decays on cycling, due to structural rearrangements upon charge-discharge. We propose to engineer the reversibility of the structural transformation also in NMC by coupling the TM cation migration with redox changes at the oxygen sublattice through dedicated TM cation replacement. We also propose to develop a Li-ion conducting coating to prevent contact between electrolyte and cathode to stop oxygen and cation loss and improve the capacity retention.

Researcher(s)

• Promoter: Hadermann Joke
• Co-promoter: Abakumov Artem
• Co-promoter: Lamoen Dirk

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The goal of this project is to develop and design a powerful method in order to unscramble mixed element nanostructures at the atomic scale in three dimensions (3D). Therefore, novel quantitative measurement tools will be combined with aberration corrected scanning transmission electron microscopy (STEM). Visualisation at the atomic scale in 3D using state-of-the-art STEM is nowadays possible for modellike systems with 1 type of chemical element present. For this purpose counting the number of atoms in each projected atomic column is of great help. However, precise determination of the atomic structure in 3D of hetero-nanostructures is currently limited because of the lack of methods to quantitatively unscramble mixed elements. In this project, atom-counting will be performed for technologically important nanostructures that are more complex than model systems, including systems with adjacent atomic number Z such as Pt-Au, Fe-Co, and Ge-Ga-As. The aim is to quantitatively characterise the number of atoms and atom types of mixed element nanostructures with single atom sensitivity. This highly challenging objective will be reached by a unique combination of physics-based modelling and advanced statistical methods. The outcome of this project will deliver the necessary input for understanding and predicting the properties of complex hetero-nanostructures and to guide the development of new nanomaterials.

Researcher(s)

• Promoter: Van Aert Sandra
• Co-promoter: Van Tendeloo Staf
• Fellow: De Backer Annick

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The titanium stabilized 15Cr-15Ni austenitic stainless steel is considered as clad and wrapper material for several current fast breeder reactor projects. It is also the primary choice for the MYRRHA reactor fuel assembly and a nuclear-grade batch of cladding tubes and bars has recently been produced by Sandvik for SCK•CEN. This project studies the precipitation of fine secondary Ti(C,N) precipitates after thermal ageing of the 15Cr-15Ni clad and bar material at temperatures relevant for service operation and during storage. Besides the control of the heat treatment parameters, it includes the characterization by Transmission Electron Microscopy (TEM) of the amount and density of secondary Ti(C,N) precipitates. Aged specimens reinforced by the dispersion of nanoscale precipitates will then be tested mechanically to investigate the influence of ageing temperature on mechanical properties.

Researcher(s)

• Promoter: Schryvers Nick

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Recently, the established division between insulators and conductors was torn down by the remarkable discovery of topological insulators. These materials are bulk insulating, but conducting at their surfaces. They receive a lot of attention for their exotic physics, interesting applications in spintronics and quantum computing and the creation of Majorana fermions (fermions that are their own antiparticles) in these materials. For the few known ones, we need better control over the band structure: most topological "insulators" are actually slightly bulk conducting. A way to tune this is through mixed crystals of topological and trivial (normal) insulators. These also allow to study the phase transition from topological to trivial insulator, for which the mechanism is controversial. So far, such mixed crystals were studied with techniques giving information on the average structure, but not the local structure. However, our preliminary data shows that local order between the different ions exists in several of these. Order will affect the electronic properties. We will study the local order in specific mixed crystals of topological – trivial insulators. We will use state-of-the-art transmission electron microscopy techniques which allow to pinpoint the positions and nature of the different ions at atomic scale. The solved structures will be used to calculate the electronic band structures using Density functional theory calculations. This gives us fundamental knowledge on the mechanism of the topological phase transition as well as the possibility to tune the electronic properties.

Researcher(s)

• Promoter: Hadermann Joke
• Fellow: Callaert Carolien

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Unitized regenerative fuel cells (URFCs) are currently attracting an increased attention as an emerging technology for storage and conversion of surplus electricity produced from renewable energy sources (solar, wind). In this context the challenge is to develop active, stable, and inexpensive electrocatalytic materials for the electrodes of URFCs. The objective of the project proposal is the design of advanced noble metal-free transition metal nano-oxides for the oxygen reduction (ORR) and oxygen evolution reaction (OER) in alkaline media in view of their application in URFCs. In order to achieve this goal we assemble an international interdisciplinary team and combine advanced characterization tools, synthesis, electrochemical methods, kinetic modeling, quantum and computational chemistry. The Russian team combines three groups working together for a long time. The Kazan group will use quantum chemical methods to predict catalytically active centers, and to calculate electron transfer rates. Using this information as an input, Moscow group will synthesize 3d-metal (Mn, Fe, Co and Ni) simple and complex nano-oxides and hydroxides by chemical methods. To better understand the role of defects, the Novosibirsk group will prepare long-lived metastable oxide nanostructures by electrodeposition. The Belgian partner will apply advanced transmission electron microscopy methods in order to access detailed information on the structure, chemical composition, cation distribution and coordination of the oxide nanoparticles in 2D and 3D. The French partner will investigate the electrochemical and electrocatalytic properties of the oxide nanoparticles, and develop kinetic models allowing to retrieve kinetic rate constants and adsorbate coverages, and provide feedback for further improvement of quantum chemical models. Achieving a molecular level understanding will allow us to design advanced oxide nanomaterials with high catalytic activities both in the ORR and OER.

Researcher(s)

• Promoter: Hadermann Joke
• Co-promoter: Abakumov Artem

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The objective of FONSENS is to develop breakthrough technologies in gas sensing that will provide higher sensitivity and superior selectivity at reduced cost and power consumption. This objective will be pursued by integrating complementary skills of EU and Russian groups. The main strategy in FONSENS for achieving enhanced sensor performances is to develop new nanostructured materials, which will allow control of concentration of active centers over a broad range for selective detection of toxic gases of different nature. The development of new generation of gas sensing materials will be supported by computational modeling with ab initio DFT calculations and a wide range of high resolution morphological and physico-chemical characterization techniques including (scanning) transmission electron microscopy and electron diffraction.

Researcher(s)

• Promoter: Lamoen Dirk
• Co-promoter: Abakumov Artem
• Co-promoter: Hadermann Joke

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Matter is a three-dimensional (3D) agglomeration of atoms. The properties of materials are determined by the positions of the atoms, their chemical nature and the bonding between them. If we can determine these parameters in 3D, we can provide the necessary input for predicting the properties and we can guide the development of new nanomaterials. The aim of this project is therefore to provide a complete 3D characterisation of complex heteronanosystems down to the atomic scale. The combination of advanced electron microscopy and novel 3D reconstruction algorithms is an innovative approach to quantify the position AND the colour (chemical nature and bonding) of each individual atom in 3D.

Researcher(s)

• Promoter: Bals Sara
• Fellow: Bladt Eva

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Nanostructured materials are found in many different forms of advanced materials. The properties of these materials strongly depend on their nanostructural features and dedicated characterization tools providing nanostatistical data are indispensable for further development of these novel materials. This project focuses on the application of an innovative combination of advanced transmission electron microscopy high-throughput nanoquantification with in-situ quantified testing methods to unravel the fundamental processes activated at the micro- and nanoscale. The latter control the nucleation, mobility and interaction of crystal defects and the resulting mechanical and thermo-mechanical properties of these materials. This combination of techniques is absolutely unique in Europe and will for the first time provide true quantified data on different fundamental processes such as crystallization in metallic glasses, martensitic phase transformations in shape memory alloys and nano-plasticity and thermally activated mechanisms in nanocrystalline Nickel. These are just a few examples of the broad variety of exciting investigations that will become possible through the objectives of this proposal. The outcome of this project will trigger the synthesis of nanomaterials with improved properties and the design of nanostructures with novel functionalities.

Researcher(s)

• Promoter: Schryvers Nick
• Fellow: Amin-Ahmadi Behnam

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This project represents a formal research agreement between UA and on the other hand SCK. UA provides SCK research results mentioned in the title of the project under the conditions as stipulated in this contract.

Researcher(s)

• Promoter: Schryvers Nick

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This project represents a research contract awarded by the University of Antwerp. The supervisor provides the Antwerp University research mentioned in the title of the project under the conditions stipulated by the university.

Researcher(s)

• Promoter: Bals Sara
• Co-promoter: Partoens Bart
• Fellow: Abakumov Artem
• Fellow: Neirinckx Alexander
• Fellow: Pfannmöller Martin
• Fellow: Pourbabak Saeid

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The NANO consortium of excellence represents the internationally renowned expertise in nanoscience at the University of Anwerp. It consists of three participating groups that are international leaders in their subfield: EMAT, CMT and PLASMANT. The consortium joins forces towards a uniform communication and collaboration in order to further strengthen the international position of the nanosciences at the University of Antwerp.

Researcher(s)

• Promoter: Verbeeck Johan
• Co-promoter: Bals Sara
• Co-promoter: Bogaerts Annemie
• Co-promoter: Partoens Bart
• Co-promoter: Schryvers Nick
• Co-promoter: Van Tendeloo Staf

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The present project focuses on two main objectives: (1) the investigation of elementary defect mechanisms controlling the growth and hydriding of nc Pd films and (2) the investigation of such mechanisms controlling the (thermo-)mechanical properties in as-deposited and hydrided nc Pd films. The research will be conducted by a combination of novel TEM techniques providing highthroughput nanostatistical data with nm resolution meanwhile allowing for in-situ nano/micromechanical testing experiments including in-situ heating and yielding quantified loaddisplacement and stress-strain curves to provide dynamical data on nanoplasticity.

Researcher(s)

• Promoter: Schryvers Nick
• Co-promoter: Idrissi Hosni

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

When light interacts with matter, it responds to this external stimulus in ways that depend on macroscopic properties but also on the microscopic details of the material. Pigments for instance, have a wavelength dependent reflection and absorption that causes the appearance of color in e.g. oil paintings. The absorption of light can also be used to capture the energy stored in solar light for use in photovoltaic solar cells. Perhaps surprisingly, the microscopic function of solar cells and pigments have a lot in common. Both absorb light and suffer from deterioration upon prolonged illumination and environmental conditions. This leads to chemical degradation (and altered colors) in historical paintings and to gradually reducing efficiencies in organic solar cells. In order to better understand their function and alteration behaviour, in this project, we propose to study in detail the microscopic origins of the capturing of light in heterogeneous materials found in oil paints and organic solar cells by combining state of the art experimental techniques based on synchrotron radiation and electron microscopy with advanced quantum mechanical models. This multidisciplinary approach will enable to improve the function and durability of future organic solar cells and will help to preserve and restore historical paintings from our cultural heritage.

Researcher(s)

• Promoter: Verbeeck Johan
• Co-promoter: Janssens Koen
• Co-promoter: Partoens Bart

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

In recent years scientists have discovered the potential of materials with extremely fine grain sizes. In many cases, reducing the grain size to sub-micron or even nanoscale dimensions indeed improves mechanical and functional properties. In this project we aim to understand the influence of the nano- and microstructure on the mechanical and functional properties such as shape memory effect, superelasticity, recovery stresses, work output, damping properties, strain hardening and ductility of Ni-Ti alloys.

Researcher(s)

• Promoter: Schryvers Nick

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The aim of this project is to quantify the structure and composition of complex heteronanostructures in three dimensions (3D) at the atomic scale. Therefore, aberration corrected transmission electron microscopy (TEM) will be combined with innovative 3D reconstruction algorithms and novel quantitative measurement tools.

Researcher(s)

• Promoter: Van Aert Sandra
• Co-promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The aim of this project is to detect extremely light atoms, to determine their atom types and to measure their positions down to picometer precision. Therefore, aberration corrected scanning transmission electron microscopy will be combined with innovative quantitative measuring.

Researcher(s)

• Promoter: Van Aert Sandra
• Co-promoter: den Dekker Arjan

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This project will quantify the concentration of cargo vapours around the ship's accommodation and investigate how to improve the situation. Wind tunnel experiments and CFD calculations will in addition to the existing on‐board measurements help to visualise the streamlines around the accommodation. Based on these results we will draw up guidelines to the crew on how to minimize cargo vapour concentrations around the superstructure in relation to the different cargo handling operations

Researcher(s)

• Promoter: Lamoen Dirk

Research team(s)

• Electron microscopy for materials research (EMAT)

Project website

Project type(s)

• Research Project

Abstract

During my PhD research, we developed and performed electron tomography experiments in order to measure the positions of the atoms in a nanostructure. However, the burning questions in the field of nanoscience can no longer be solved by only determining the atomic structure. Nowadays, it becomes crucial to measure the chemical nature and even the oxidation state of each individual atom in a nanostructure as well. Therefore, the aim of this project is to push the limits of electron tomography beyond the state-of-the-art and to provide a complete 3D quantitative chemical characterisation of complex hetero-nanosystems down to the atomic scale.

Researcher(s)

• Promoter: Bals Sara
• Fellow: Goris Bart

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

In this project, we propose to extend this concept to waves with a so-called topological charge. Such waves behave similar to a tornado as they have a component of velocity around a central axis. The mathematical description of such waves is fundamentally distinct from 'normal' waves, as they cannot be transformed into one another by a smooth deformation of the wave fronts. This difference is called a topological difference and it can be shown that this property of the wave is quite robust against scattering to objects. This means that in most cases a wave with vortex character will keep this character after scattering. There are important exceptions however, as the scattering object itself possesses a 'handedness', i.e. when left and right hand variants of an object exist. Such objects are called chiral and we will demonstrate that one can distinguish between left and right handed variants making use of electron vortex waves.

Researcher(s)

• Promoter: Verbeeck Johan
• Fellow: Juchtmans Roeland

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The goal of my proposal is to develop and design a powerful method to reconstruct 3D nanostructures on the atomic scale from single 2D STEM images. Determining the full 3D structure of heterogeneous structures will allow the identification of coreshell structures, impurities and other defect structures. This is highly desirable to understand and adequately tune functional properties. In comparison to other approaches aiming at atomic scale 3D reconstruction techniques, the proposed method relies on a simultaneous acquisition of 2D images each carrying specific information concerning the number and depth location of all atoms present. This so far unique approach of retrieving the 3D atomic structure will considerably reduce beam damage and will even enable me to introduce the fourth dimension of time in electron microscopy. In this way, it becomes possible to reveal atomic scale dynamics allowing, for example, the observation of diffusion processes and the determination of different equilibrium geometries of atomic clusters.

Researcher(s)

• Promoter: Van Aert Sandra
• Fellow: van den Bos Karel

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The goal of this FWO Aspirant proposal is to contribute to the theoretical and conceptual understanding of these newly created vortex beams and their interaction with matter. With this proposal we want to complement the experimental capabilities with a solid foundation of theoretical understanding in order to stay at the forefront of electron vortex research.

Researcher(s)

• Promoter: Verbeeck Johan
• Co-promoter: Partoens Bart
• Fellow: Van Boxem Ruben

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This project represents a research agreement between the UA and on the onther hand IWT. UA provides IWT research results mentioned in the title of the project under the conditions as stipulated in this contract.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This project represents a research agreement between the UA and on the onther hand IWT. UA provides IWT research results mentioned in the title of the project under the conditions as stipulated in this contract.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The goal of this program is to investigate the electronic properties of conventional, well-known 2-D semiconductors, which, however, obtain a rich Dirac band structure by their honeycomb nanogeometry. To reach this goal, we propose further efforts in the theoretical development, fabrication and electronic characterization of such systems.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The project entitled "Innovative Material Systems for Solar Energy Harvesting in Photoelectrochemical Cells"(InSOL)" addresses the aspect of the 4th New Indigo Partnership Programme call on "New Material Systems for Renewable Energy". In this project, we aim to perform comprehensive theoretical and experimental investigations for the development of new graphene based earth-abundant material heterostructures for solar energy conversion through photoelectrochemical (PEC) cells. The key objective of this study is to identify new material combinations yielding high photon absorption and conversion efficiency under the constraint of using earth-abundant elements only. In a first step, ab-inito methods around Density Functional Theory (DFT) including the use of hybrid functionals will be used to screen promising material combinations with respect to their electronic and optical properties prior to actual device fabrication. Here, strategies will be developed how the single components with high performances in specific areas, for instance absorption of photons and conduction of charge carriers, can be combined to multi-material systems achieving the required overall functionality. The use of graphene as supporting material will provide an excellent electrical conductor for superior charge carrier drainage from the photoactive layers. In a second step, nano-heterostructures comprising earth abundant materials with superior visible-light activity will be developed by cost-effective wet chemical and gas phase methods. Of special importance in the proposed project is the engineering of the interfacial properties of the nano-heterostructures in order to obtain improved charge carrier separation and unhindered charge transport across the interfaces of the theoretically optimized materials. Therefore, the nano-heterostructures will be engineered through incorporation of conductive carbon nanostructures for facilitating interfacial charge carrier transport. The proposed studies on charge-transfer processes, chemical kinetics and photogenerated electron-hole pair recombination rates will synergize the hetero-contacts in the nano-catalyst and the electrical transport parameters. The structure and composition of the layers and interfaces will be monitored at atomic, nano and micrometer scale using transmission electron microscopy, providing information on the crystallographic phases and the crystallographic quality of the prepared samples. In a feedback loop the synthesis of the heterostructures will be adjusted according to the structural analysis such that optimal interface properties are achieved. The electrochemical characteristics of the hydrogen fuel forming photo-catalysts have to be analysed and related with their physical and structural properties. All of these data will be considered to elucidate the best performance for having the highest efficiency of the whole system. Regarding the big potential of solar energy conversion and the expected strong increase of the demand for clean energy worldwide this project also aims at fostering international collaboration that is highly appropriate in the field of solar energy materials due to its multidisciplinary character.

Researcher(s)

• Promoter: Hadermann Joke

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This project represents a formal research agreement between UA and on the other hand the Hercules Foundation. UA provides the Hercules Foundation research results mentioned in the title of the project under the conditions as stipulated in this contract.

Researcher(s)

• Promoter: Schryvers Nick
• Co-promoter: Caen Joost
• Co-promoter: Hadermann Joke
• Co-promoter: Van Aert Sandra

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This project represents a formal research agreement between UA and on the other hand IMEC. UA provides IMEC research results mentioned in the title of the project under the conditions as stipulated in this contract.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This is a fundamental research project financed by the Research Foundation - Flanders (Fonds voor Wetenschappelijk Onderzoek Vlaanderen (FWO)). The project was subsidized after selection by the FWO-expert panel.

Researcher(s)

• Promoter: Van Tendeloo Staf

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The objective of this project is to develop a tool that predicts air quality levels in urban environments with quantified uncertainty intervals that account for the atmospheric variability. It is an agreement between the University of Antwerp and IWT

Researcher(s)

• Promoter: Van Tendeloo Staf
• Co-promoter: Gorlé Catherine
• Fellow: Garcia Sánchez Clara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The overall objective of the research proposal is to elucidate the chemical composition of the target surface under different experimental conditions, and using this chemical information to calculate the electron yield by first-principles techniques and the sputter yield by Monte Carlo techniques. In this way, the project combines experiments and calculations to obtain quantitative data about two fundamental processes during reactive magnetron sputtering.

Researcher(s)

• Promoter: Lamoen Dirk

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

We propose a unique combination between in-situ evaluation of electrochemical deposition by nanocluster aggregation, state of the art atomic-scale characterization, and electrochemical modeling of the underlying processes. By means of this approach, we aim to provide a new alternative to obtain enhanced supported nanostructures by exploring nanocluster self-assembly during electrochemical deposition processes.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

In this project we aim at physically based modelling and simulation of the mechanical behaviour of polycrystalline metallic thin film systems and micropillars under cyclic loads.The ultimate goal of the project is to provide physical foundations for computational design of fatigue resistant microstructures by establishing a predictive multiscale modelling framework for the early stages of fatigue failure. This will be of benefit for a vast range of technological applications including the enhancement of fatigue resistance by surface treatment and fatigue of microscale components.

Researcher(s)

• Promoter: Schryvers Nick

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This project represents a formal research agreement between UA and on the other hand the client. UA provides the client research results mentioned in the title of the project under the conditions as stipulated in this contract.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The aim of this project is therefore to provide a complete 3D characterisation of complex hetero-nanosystems down to the atomic scale. The combination of advanced aberration corrected electron microscopy and novel 3D reconstruction algorithms is envisioned as a groundbreaking new approach to quantify the position AND the colour (chemical nature and bonding) of each individual atom in 3D for any given nanomaterial.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The project aims at developing a prototype device for generation of vortex electron beams (VEBs). VEBs enable probing magnetic state of matter down to atomic scale, manipulate nanoparticles or determine chirality of crystals. The major valorization tracks are seen as licensing production of VEB-generating devices and through bilateral contractual research with the industrial parties in Flanders and abroad.

Researcher(s)

• Promoter: Verbeeck Johan
• Co-promoter: Abakumov Artem

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This project will focus on the application of high resolution imaging and spatially resolved spectroscopy in a (S)TEM to three specific classes of nanomaterials; nanoscale oxides, superconducting nanocrystalline diamond and hybrid metal-organic frameworks (MOFs). Key research questions in each of these domains will be addressed, in collaboration with renowned materials synthesis labs.

Researcher(s)

• Promoter: Van Tendeloo Staf
• Fellow: Turner Stuart

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Matter is a three-dimensional (3D) agglomeration of atoms. The properties of materials are determined by the positions of the atoms, their chemical nature and the bonding between them. If we can determine these parameters in 3D, we can provide the necessary input for predicting the properties and we can guide the development of new nanomaterials. The aim of this project is therefore to provide a complete 3D characterisation of complex heteronanosystems down to the atomic scale. The combination of advanced electron microscopy and novel 3D reconstruction algorithms is an innovative approach to quantify the position AND the colour (chemical nature and bonding) of each individual atom in 3D.

Researcher(s)

• Promoter: Bals Sara
• Fellow: Bladt Eva

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This project represents a formal research agreement between UA and on the other hand Erasmus Mundus. UA provides Erasmus Mundus research results mentioned in the title of the project under the conditions as stipulated in this contract.

Researcher(s)

• Promoter: Bals Sara
• Co-promoter: Verbeeck Johan

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This is a fundamental research project financed by the Research Foundation - Flanders (FWO). The project was subsidized after selection by the FWO-expert panel for the sabbatical year of Van Tendeloo.

Researcher(s)

• Promoter: Van Tendeloo Staf

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The main goals of the SB01 project "Mechanical properties and chemical bonding at the interfaces in polymer-based composite materiais" (InterPoCo) within the H-INT-S program are to (i) develop and apply a set of experimental and computational tools for comprehensive structural, compositional and quantitative mechanical characterisation of the interfaces in polymer-based composites at na no- and microscale level, (ii) to measure and predict structural, electronical, compositional, thermodynamica I and mechanical properties of bulk polymers and interfaces in polymer-based composites, (iii) to validate and improve the prediction reliability by emphasizing the interplay between modelling and experimental data obtained using a high-throughput approach and advanced characterisation results and (iv) to provide currently unavailable information on the above aspects to the running and future vertical SIBO programs.

Researcher(s)

• Promoter: Schryvers Nick
• Co-promoter: Abakumov Artem

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This project represents a research contract awarded by the University of Antwerp. The supervisor provides the Antwerp University research mentioned in the title of the project under the conditions stipulated by the university.

Researcher(s)

• Promoter: Verbeeck Johan
• Fellow: Verbeeck Johan

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Oxides form a challenging subgroup of materials for tomorrow's technology and can be applied in fuel cells for greener cars, as faster nonvolatile memory that can reduce power consumption in computers, as ultrasensitive magnetic sensors for medical applications and many more. The range of physical properties of oxides is enormous and can even be expanded by bringing different oxides in contact with each other where so-called emergent properties occur at the interface. The reason why this happens is still heavily debated but naturally occurring ordering phenomena play an important role. In this project we propose to study such ordering of e.g. local atomic charges or atomic orbitals or the spin of atomic electrons with transmission electron microscopy. This is a fundamentally more direct method of studying this topic as compared to commonly used techniques which only give information on the average ordering over large volumes of material. It is exactly this direct visualization that will allow us to study the ordering phenomena near interfaces and defects in crystals in order to better understand the physics and properties of oxide devices.

Researcher(s)

• Promoter: Verbeeck Johan
• Co-promoter: Turner Stuart
• Co-promoter: Van Tendeloo Staf

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This project aims at an atomic scal study of interaction between iron oxide and modifying promoters, added to inhibit deactivation in cycling processes. This implies looking at the materials during heating or reaction with nano-scale techniques such as operando XAS and in situ TEM.

Researcher(s)

• Promoter: Van Tendeloo Staf
• Co-promoter: Turner Stuart

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Grain boundaries in polycrystalline materials are known to play a critical role in determining their electronic properties. For several reasons, polycrystalline materials are at the heart of many present day electronic devices. Thus, a thorough understanding of the physics of grain boundaries is of fundamental importance for the design of devices with increased efficiency. The problem is compounded by the fact that the typical presence of nonnegligible concentrations of impurities and defects leads to a phenomenology that can be very different from that occurring in the bulk. In this project we will consider as a case study the chalcopyrite CuIn1-xGaxSe2 (CIGS) systems, which are of great current interest. Indeed, although today photovoltaic cells are still largely built with Si-based absorber layers, the low absorption coefficient of Si has prompted research on cells based on thin-film absorber layers, with higher power-to-weight ratios.

Researcher(s)

• Promoter: Lamoen Dirk

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The goal of this project is therefore to develop and apply quantitative methods in order to visualize and identify atoms and next to precisely measure their positions in three dimensions. This will open up a whole new range of possibilities to understand and characterize nanocrystals at the atomic level and to help developing innovative materials with revolutionary interesting properties.

Researcher(s)

• Promoter: Van Aert Sandra
• Co-promoter: Van Dyck Dirk

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

SUNFLOWER is a collaborative research project of 17 partner institutions from science and industry. Its goal is the development of highly efficient, long-lasting, cheap and environmentally friendly printed organic photovoltaics. TEM will be used to charactrize degradation.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The ESTEEM2 project integrates European electron microscopy laboratories in a range of activities that provide a service to a range of physical science disciplines. This European Research Infrastructure will offer service provision that enables users to access the most advanced electron microscopes in an integrated fashion.

Researcher(s)

• Promoter: Van Tendeloo Staf

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The main objective of this proposal is to push aberration corrected transmission electron microscopy (TEM) toward precise measurements of unknown structure parameters. Although the resolution of these state-of-the-art instruments has greatly been improved by optimizing the lens design, equally fundamental changes in the image processing and acquisition methods are required in order to have the instrument performing at the limits of its capabilities. Therefore, use will be made of statistical parameter estimation theory. The starting-point is the availability of a parametric model describing the expectations of the images. This is a physics-based model depending on the unknown structure parameters. It describes the interaction of the electrons with the object, the transfer in the microscope, and the detection. Next, the unknown parameters are estimated by fitting this model to the experimental images using a criterion of goodness of fit. Through a combination of available techniques in TEM, the focus in this project will be to determine atom positions with picometer precision for heavy as well as for light atoms, precise chemical composition analysis, and detection of single atoms. Finally, in order to study beam sensitive matter without radiation damage, the principles of statistical experimental design will be used to determine the minimally required electron dose in order to attain a pre-specified precision.

Researcher(s)

• Promoter: Van Aert Sandra
• Fellow: De Backer Annick

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The overall objective of the present proposal is the advancement of the predictive capabilities of multi-physics flow simulations. Turbulence and turbulent mixing are fundamental processes in the vast majority of multi-physics applications and the turbulence models currently used within the engineering community lack predictive capabilities beyond the specific conditions for which they were designed. I therefore intend to specifically focus on the epistemic uncertainty quantification (EUQ) of existing turbulence and turbulent mixing models.

Researcher(s)

• Promoter: Van Tendeloo Staf
• Fellow: Gorlé Catherine

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

In this project, we propose to extend this concept to waves with a so-called topological charge. Such waves behave similar to a tornado as they have a component of velocity around a central axis. The mathematical description of such waves is fundamentally distinct from 'normal' waves, as they cannot be transformed into one another by a smooth deformation of the wave fronts. This difference is called a topological difference and it can be shown that this property of the wave is quite robust against scattering to objects. This means that in most cases a wave with vortex character will keep this character after scattering. There are important exceptions however, as the scattering object itself possesses a 'handedness', i.e. when left and right hand variants of an object exist. Such objects are called chiral and we will demonstrate that one can distinguish between left and right handed variants making use of electron vortex waves.

Researcher(s)

• Promoter: Verbeeck Johan
• Fellow: Juchtmans Roeland

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The goal of this FWO Aspirant proposal is to contribute to the theoretical and conceptual understanding of these newly created vortex beams and their interaction with matter. With this proposal we want to complement the experimental capabilities with a solid foundation of theoretical understanding in order to stay at the forefront of electron vortex research.

Researcher(s)

• Promoter: Verbeeck Johan
• Co-promoter: Partoens Bart
• Fellow: Van Boxem Ruben

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

We aim to characterize strain at the atomic scale near interfaces in (core-shell) nanoparticles. Such interfaces have a large impact on the properties of the structures and it is therefore crucial to gain a thorough understanding on the atomic structure in order to optimize these core shell particles towards possible optical applications. Moreover, we will investigate the presence of lattice strain near atomic defects such as dislocations or vacancies based on the atomic resolution electron tomography technique that was developed in the first part of the project.

Researcher(s)

• Promoter: Bals Sara
• Fellow: Goris Bart

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Proposed by the University, the Francqui Foundation each year awards two Francqui Chairs at the UAntwerp. These are intended to enable the invitation of a professor from another Belgian University or from abroad for a series of ten lessons. The Francqui Foundation pays the fee for these ten lessons directly to the holder of a Francqui Chair.

Researcher(s)

• Promoter: Van Tendeloo Staf

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The EUROTAPES project will address two broad objectives: 1/ the integration of the latest developments into simple conductor architectures for low and medium cost applications and to deliver +500m tapes. Defining of quality control tools and protocols to enhance the processing throughput and yield to achieve a pre-commercial cost target of 100 €/kAm. 2/ Use of advanced methodologies to enhance performance (larger thickness and Ic, enhanced pinning for high fields, reduction of ac losses, increased mechanical strength).

Researcher(s)

• Promoter: Van Tendeloo Staf

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

"Soft matter" is anything from a well-defined term. It is used to represent a broad class of materials including colloids, polymers, biological specimens and biomaterials. Although the use of such materials becomes increasingly important in nanotechnology, a successful implementation can only be reached through a thorough structural investigation at the nanolevel. Electron microscopy is the most widely used technique to study inorganic (nano)materials, even at the atomic scale. Such investigations however, are far from straightforward when soft matter is considered. Therefore this application aims at an environmental scanning electron microscope as well as a cryo ultramicrotome.

Researcher(s)

• Promoter: Bals Sara
• Co-promoter: Adriaensen Dirk
• Co-promoter: De Wael Karolien

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The IAP Functional Supramolecular Systems will identify and demonstrate new fundamental concepts in light conversion and manipulation, in catalysis and separations, and in design of responsive and adaptable systems, based on concepts of supramolecular assembly and function.

Researcher(s)

• Promoter: Van Tendeloo Staf

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This is a fundamental research project financed by the Research Foundation - Flanders (FWO). The project was subsidized after selection by the FWO-expert panel.

Researcher(s)

• Promoter: Van Tendeloo Staf

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

In this project I will exploit new possibilities opened up by the recent succesful demonstration of our ability to create electron vortex beams in a transmission electron microscope. Electron vortex beams carry a helical phase and angular momentum around their propagation axis. They form the counterpart of optical vortex beams that were invented almost 20 years ago and have lead to many exciting new applications in optics.

Researcher(s)

• Promoter: Verbeeck Johan

Research team(s)

• Electron microscopy for materials research (EMAT)

Project website

Project type(s)

• Research Project

Abstract

The aim of the present project is to use a combination of conventional and advanced TEM techniques available in the EMAT group to unravel the fundamental properties of structural defects and morphologies involved in the plastic deformation of different nc metallic films. This constitutes the key for the improvement of the mechanical behavior and the reliability of these films.

Researcher(s)

• Promoter: Schryvers Nick

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This is a fundamental research project financed by the Research Foundation - Flanders (FWO). The project was subsidized after selection by the FWO-expert panel. For the successful realization of the next generation of nano-scale devices, the understanding of contact formation needs to be improved. Both the aggressive downscaling of traditional silicon technology, as well as the introduction of high mobility or large bandgap semiconductors (Ge, InGaAs, GaN, SiC), move contact formation into areas of solid state physics which are relatively unexplored. This project aims at a fundamental study of metal/semiconductor contacts at nanoscale dimensions.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This project represents a formal research agreement between UA and on the other hand a private institution. UA provides the private institution research results mentioned in the title of the project under the conditions as stipulated in this contract.

Researcher(s)

• Promoter: Turner Stuart

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This project represents a formal research agreement between UA and on the other hand Umicore. UA provides Umicore research results mentioned in the title of the project under the conditions as stipulated in this contract.

Researcher(s)

• Promoter: Van Tendeloo Staf
• Fellow: Van Havenbergh Kristof

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Silver present in photographic materials oxidizes, migrates and reduces in the emulsion causing degradation of the image. This PhD project investigates these modifications of silver by means of electron microscopy and compares the degradation process before and after different treatment methods, e.g. local atmospheric plasma cleaning. As a result the most appropriate treatment method for silver oxidation in photographic materials will be suggested after quantitative analyses.

Researcher(s)

• Promoter: Schryvers Nick
• Co-promoter: Caen Joost

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The physical and chemical properties of materials are largely determined by the crystal structure of these materials. Therefore manipulating the crystal structure means altering and controlling the properties. The structure of most materials can be solved from X-ray diffraction (XRD) data. However, for nanomaterials or highly defective structures often electron diffraction (ED) data are the only data available. However, structure solution from ED data is classically very difficult and often impossible because the intensity of the reflections strongly depends on sample thickness, orientation, etc. Using Precession ED (PED) (recorded by precessing the beam on a cone) the data become less dependent of those factors, enabling the use of structure solution procedures developed for XRD on PED data. In order to obtain structure solution from single crystal XRD data, it was necessary to determine all factors influencing the data and incorporate their effect in the calculations. For PED all these factors now have to be figured out anew. In this project, the most important affecting factors and how to take them into account will be determined. The PED technique will also be generalized to n-dimensional space (calculations and software), so that it will be applicable for all crystals, including aperiodic crystals.

Researcher(s)

• Promoter: Hadermann Joke
• Fellow: Van Rompaey Senne

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The objective of NAPROM is to develop novel active corrosion protection coatings for metals utilizing self-healing organic coatings (employing different healing mechanisms) and corrosion inhibitors (with different delivery mechanisms), aiming at an extended coating life-time and an improved active corrosion protection.

Researcher(s)

• Promoter: Van Tendeloo Staf

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The central objective of this ESMI project is to create a top-level interdisciplinary research infrastructure available to a broad European materials research community. This is of crucial importance to the EU in view of the European strategy for nanosciences and nanotechnology and its implementation report that identifies "a lack of leading interdisciplinary infrastructures". ESMI offers the most important experimental and synthesis techniques and combines world-class infrastructures with cutting edge scientific expertise through a sophisticated networking programme.

Researcher(s)

• Promoter: Van Tendeloo Staf

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This project aims at the development of new measurement techniques using transmission electron microscopy in order to realize a breakthrough towards quantitative three-dimensional structure determination of nanomaterials at atomic scale.

Researcher(s)

• Promoter: Van Aert Sandra
• Co-promoter: Sijbers Jan

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

We will study the structure and optical properties of suitable new and old incommensurate scheelite based structures to determine this relation and optimize the optical properties by achieving the optimal cation arrangement.

Researcher(s)

• Promoter: Hadermann Joke
• Co-promoter: Abakumov Artem
• Co-promoter: Verbeeck Johan

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This project relies on a cross-over between artistic jewellery creation on the one hand and innovative materials science and technology on the other. Since observation is highly subjective, the way of presenting "things" can evoke very different feelings. In this project, classical jewellery materials, such as diamond and gold, will be looked at differently, mounted differently and we will experiment with new techniques to change typical colours and connections.

Researcher(s)

• Promoter: Van Tendeloo Staf

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This project represents a research contract awarded by the University of Antwerp. The supervisor provides the Antwerp University research mentioned in the title of the project under the conditions stipulated by the university.

Researcher(s)

• Promoter: Lamoen Dirk
• Fellow: Govaerts Kirsten

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The goal of the IFOX project is to explore, create and control novel electronic and magnetic functionalities, with focus on interfaces in complex transition metal oxide heterostructures to develop the material platform for novel 'More than Moore' (MtM) and 'beyond CMOS' electronics, VLSI integratable with performance and functionality far beyond the state-of-art.

Researcher(s)

• Promoter: Van Tendeloo Staf

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The first purpose of this research project is to investigate the micro- and nano-structural features of the martensite twin and magnetic domain structure in Co-Ni-Al alloys and to relate those to the transformation characteristics and mechanical behavior of these materials. The next purpose is to develop advanced Lorentz microscopy techniques at the host laboratory, extending the possible applications of the lab to magnetic materials.

Researcher(s)

• Promoter: Schryvers Nick

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

NaPoS will focus on structural hybrid materials, more specifically on steel fibres or plates/sheets combined with polymers. The aim of the NaPoS research project, within the NanoForce SIBO program is to develop a scientific base to optimise the interaction between steel and polymers.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Structural and chemical characterization of aCNTb's on the atomic level as well as micro-scale will be investigated. Mechanical deformation of aCNTb's as well as aCNTb-based composites will be studied by means of in-situ characterization techniques. Develop a novel process for the synthesis and extraction of CNTs to aCNTb's in a single continuous process to obtain high stiffness and high toughness aCNTb's.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

We will study the properties of nanoparticles using advanced transmission electron microscopy (TEM) techniques performed in a state-of-the-art aberration-corrected TEM. By harnessing the full potential of aberration-corrected TEM, we will be able to image the morphology and surface structure of nanoparticles down to the atomic level in all three dimensions. Aberration correction will allow these analyses to be performed at low acceleration voltages, meaning beam-sensitive materials and surface functionalisation can be imaged for the first time.

Researcher(s)

• Promoter: Van Tendeloo Staf
• Fellow: Turner Stuart

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The main objective of this proposal is to push aberration corrected transmission electron microscopy (TEM) toward precise measurements of unknown structure parameters. Although the resolution of these state-of-the-art instruments has greatly been improved by optimizing the lens design, equally fundamental changes in the image processing and acquisition methods are required in order to have the instrument performing at the limits of its capabilities. Therefore, use will be made of statistical parameter estimation theory. The starting-point is the availability of a parametric model describing the expectations of the images. This is a physics-based model depending on the unknown structure parameters. It describes the interaction of the electrons with the object, the transfer in the microscope, and the detection. Next, the unknown parameters are estimated by fitting this model to the experimental images using a criterion of goodness of fit. Through a combination of available techniques in TEM, the focus in this project will be to determine atom positions with picometer precision for heavy as well as for light atoms, precise chemical composition analysis, and detection of single atoms. Finally, in order to study beam sensitive matter without radiation damage, the principles of statistical experimental design will be used to determine the minimally required electron dose in order to attain a pre-specified precision.

Researcher(s)

• Promoter: Van Aert Sandra
• Fellow: De Backer Annick

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Knowledge on the 3 dimensional structure and composition of nanomaterials at the atomic scale is indispensable when one wants to understand the physical properties of nanostructures in comparison to their bulk counterparts. Several groups have therefore dedicated a lot of effort towards reaching atomic resolution in 3 dimensions by transmission electron microscopy (TEM), but most studies remain theoretical or present experimental results which are not yet convincing. In most of these studies one specific TEM technique is selected, but in my project, I propose to combine different state-of-the-art TEM techniques and to exploit the information they can deliver as much as possible. Such a hybrid approach defines a complete new path on the route towards atomic resolution tomography. I will combine a limited number of in zone-axis projections, yielding atomic resolution, with a full tilt series of projections acquired at lower magnifications. Furthermore, I will expand the so-called "depth sectioning technique" to push its resolution to the sub nanometer level. Beam damage will be kept at a strict minimum by operating an aberration corrected TEM at low acceleration voltage. This will allow me to study the 3D atomic structure of core-shell particles and interfaces present in assemblies of nanocrystals.

Researcher(s)

• Promoter: Bals Sara
• Fellow: Goris Bart

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

For materials with decreasing dimensions the surface to bulk ratio will become more and more important. Since the properties of a material are often determined by its surface (e.g. painting can prohibit rust), surface characterization will become extremely important when the dimensions are in the nanometer range. Such nanomaterials can be studied chemically as well as structurally through advanced electron microscopy. The challenge of this project is to study the surface of nanomaterials (hard matter, mostly metallic nanoparticles) in contact with soft matter (polymers, nanotubes, organic molecules, ¿). This is a very delicate experiment and therefore one has to find the most ideal set up for recording and analysis. However we have good hope that this can be realized in the first part of this project with the help of the experienced EMAT group. In the second part of the project we will apply the optimized technique to analyze the interaction between porous materials and metallic nanoparticles and to functionaled nanomaterials.

Researcher(s)

• Promoter: Van Tendeloo Staf
• Fellow: Van Havenbergh Kristof

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The project WeTCOat aims at building generic knowledge in TCO precursor synthesis and formulation, film formation through wet deposition, thermal processes, annealing behaviour and their influence on the layers' performance in view of developing a cost effective, high throughput deposition technology for photovoltaic modules.

Researcher(s)

• Promoter: Hadermann Joke

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The goal of the PhyCIGS project is to set up a spearhead knowledge based on thin film PV module production on the basis of breakthrough production technology by means of solution based processes based on CIGSSe chemistry.

Researcher(s)

• Promoter: Hadermann Joke

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The research aim of absCIGS is twofold. First, it aims at the development of a lab-scale non-vacuum baseline process for the formation of CIGS absorber layers, leading to cells with a conversion efficiency of 15%. Second, this work is complemented by the scientific understanding of the different steps in the process, running from the formation of the CIG5 precursors to the film transformation process. To achieve this, absCIGS sets great store by obtaining full control over the input/output relations, where the input is a dispersion of precursor nanoparticles (NPs) and the output is a dense CIGS TF.

Researcher(s)

• Promoter: Hadermann Joke

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

New Ti-Ni-based alloys will be investigated by various TEM techniques with the aim of understanding the nano- and microstructure of special low hysteresis and high reversibility shape memory alloys.

Researcher(s)

• Promoter: Schryvers Nick

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Magnetic Resonance imaging plays a crucial role in stem cell research in order to investigate whether administered stem cells are able to migrate to the target organ, locally survive, differentiate and contribute to regenerated tissue. However, knowledge regarding the interaction of MRI contrast agents with (sub)cellular structures is lacking. In this project, we will use advanced TEM techniques to investigate different MRI contrast agents and loading techniques for neural stem cells.

Researcher(s)

• Promoter: Bals Sara
• Co-promoter: Ponsaerts Peter
• Co-promoter: Van Der Linden Annemie

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The project involves a collaboration between chemists and chemical engineers in the field of heterogeneous catalysis. The aim is to characterize and to fully understand the active site of the catalyst on the atomic level, in order to build catalysts with improved properties in a reactor in the chemical industry.

Researcher(s)

• Promoter: Van Tendeloo Staf

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This project represents a formal research agreement between UA and on the other hand EU. UA provides EU research results mentioned in the title of the project under the conditions as stipulated in this contract.

Researcher(s)

• Promoter: Van Tendeloo Staf

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The project aims to achieve original, in-depth insights into the nucleation mechanisms of nanocrystalline diamond films in the presence of metal containing interlayers with different compositions, deposited by means of aqueous CSD. Through the obtained understanding, the nucleation ¿ growth mechanism can be controlled with positive effect, leading to the growth of uniform NCD materials by means of MWPECVD onto a wide variety of substrates. In this way, fundamental research in new areas of application will become possible.

Researcher(s)

• Promoter: Verbeeck Johan

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The main goal of this project is to understand the formation of metallic nanowires mediated by protein-derived biomolecular templates in such a way that the properties of the fabricated nanowires, including diameter and coverage, become controllable. This goal will be achieved by investigating the effect of different process parameters on the morphology of the nanowires. The structural information which is obtained by TEM and AFM will be combined with the outcome of the modeling studies.

Researcher(s)

• Promoter: Bals Sara
• Co-promoter: Milosevic Milorad

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The aim of this research project is to determine unknown structure parameters such as atom positions, concentrations of atoms, atom types, and energy levels of inelastic excitations, in a quantitative way from experimental measurements obtained by means of electron microscopy. Therefore, use will be made of statistical parameter estimation theory which is expected to provide a considerable improvement in accuracy, precision and reproducibility in comparison to conventional ad-hoc methods which are currently used to extract parameters from experimental measurements.

Researcher(s)

• Promoter: Van Aert Sandra
• Co-promoter: Verbeeck Johan

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The general objective of the project is to apply the focused ion beam (FIB) technique (UA) to produce zeolite slices of 50 - 100 nm thickness at various locations and with different orientations and to further perform a detailed structural analysis of these slices with High Resolution TEM.

Researcher(s)

• Promoter: Schryvers Nick

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This is a fundamental research project financed by the Research Foundation - Flanders (FWO). The project was subsidized after selection by the FWO-expert panel.

Researcher(s)

• Promoter: Van Tendeloo Staf
• Co-promoter: Van Dyck Dirk

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Tendeloo Staf

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This project represents a research contract awarded by the University of Antwerp. The supervisor provides the Antwerp University research mentioned in the title of the project under the conditions stipulated by the university.

Researcher(s)

• Promoter: Van Tendeloo Staf
• Co-promoter: Hadermann Joke
• Co-promoter: Schryvers Nick
• Co-promoter: Van Dyck Dirk
• Co-promoter: Verbeeck Johan
• Fellow: Abakumov Artem

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This project did and will give further insight into the molecular mechanisms of silica structuring to enable design and synthesis of tailor made materials. Zeolite formation has been discovered to be based on self-organization of nanoscopic precursor species. Shear and convection have strong effect on this self organization process, which only can be studied under microgravity conditions.

Researcher(s)

• Promoter: Van Tendeloo Staf

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The goal of this Scientific Research Community (Wetenschappelijke Onderzoeksgemeenschap, WOG) of the FWO-Vlaanderen is to intensify the collaboration between the different research groups in Flanders which are active in the field of the computational modeling of materials. In addition a collaboration with the external partners will be set up or intensified.

Researcher(s)

• Promoter: Lamoen Dirk

Research team(s)

• Electron microscopy for materials research (EMAT)

Project website

Project type(s)

• Research Project

Abstract

Ni-Ti based alloys are at present the mostly used materials in shape memory and superelastic components for applications in a wide variety of fields ranging from stents and orthopedic wires in the medical sector over mechanical actuators to various clutching devices. The martensitic transformation from a cubic B2 austenite structure to a monoclinic B19' martensite structure is the basis for this special behavior. Depending on the application different compositions are used, usually around the equiatomic 50-50, although recently a lot of research has been conducted into ternary systems (with additions of Cu, Hf, Zr, Au, Pt, Pd). The starting material receives a specific thermal treatment resulting in the growth of nano- to micron sized precipitates with type, size and distribution depending on temperature, period of the treatment and possible external stress conditions. These precipitates have a concrete influence on the phase transformation behavior and functional conditions of these materials. A proper understanding of their three-dimensional distribution is thus of crucial importance for the further development of this technology, e.g., in the direction of the important higher temperature domain for applications in the context of engines.

Researcher(s)

• Promoter: Schryvers Nick

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This is a fundamental research project financed by the Research Foundation - Flanders (FWO). The project was subsidized after selection by the FWO-expert panel.

Researcher(s)

• Promoter: Van Tendeloo Staf

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The goal of this project is to realize and fully characterize new multiferroics. The chosen materials are based on the prediction of multiferroic properties in perovskite based oxides with A cations with a lone electron pair in combination with magnetic B cations. The lone pair will provide the ferroelectric properties, while the magnetic B-cations take care of the magnetic properties.

Researcher(s)

• Promoter: Hadermann Joke

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The primary objective of this SBO is to develop advanced tools for pragmatic materials modeling. However, to stimulate the interaction with experimental work at Flamac and their industrial partners early on, we have targeted one application area; particularly optical thin film materials. These applications have been chosen on the basis of their high technological relevance, industrial interest in Flanders, environmental issues, and feasibility to make impact with modeling.

Researcher(s)

• Promoter: Lamoen Dirk
• Co-promoter: Partoens Bart

Research team(s)

• Electron microscopy for materials research (EMAT)

Project website

Project type(s)

• Research Project

Abstract

The aim of this project is threefold. First, we aim at the generation of supported metal and alloy particles on different substrates by surface mediated chemical or electrochemical deposition. Second, we concentrate on the modification of these particles by changing their surface properties. In view of the complexity surrounding the investigation of the structure and electronic properties of systems with nanoscale dimensions, a variety of complementary experimental methods will be used. The unification of those techniques into a methodologically homogeneous approach is the third goal of the project.

Researcher(s)

• Promoter: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This project represents a formal research agreement between UA and on the other hand a private institution. UA provides the private institution research results mentioned in the title of the project under the conditions as stipulated in this contract.

Researcher(s)

• Promoter: Van Tendeloo Staf

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Tendeloo Staf
• Fellow: Isaeva Anna

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Classical electro-polishing methods have been already for a long time insufficient to produce all TEM samples, but now they do not even suffice for alloys. One then turns to the alternative of ion milling, but this induces a lot of damage to the remaining material. In order to minimize this damage, a dedicated approach has to be made, for which the experience from intentional radiations is certainly a big advantage.

Researcher(s)

• Promoter: Schryvers Nick
• Fellow: Zelaya Eugenia

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

There are three main goals in this project: the optimisation of the practical implementation of precession electron diffraction on incommensurately modulated materials, the development of the software necessary for the treatment of these experimental results, and the application of the resulting new possibilities on hitherto unrefined materials.

Researcher(s)

• Promoter: Hadermann Joke

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This project represents a research contract awarded by the University of Antwerp. The supervisor provides the Antwerp University research mentioned in the title of the project under the conditions stipulated by the university.

Researcher(s)

• Promoter: Van Tendeloo Staf
• Co-promoter: Bogaerts Annemie
• Co-promoter: Peeters Francois

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The target of the present project is to optimize and standardize the FIB preparation methods for a specific class of materials, in this case alloys with a large variety of chemical elements and sample shapes and with the aim on quantitative TEM. Also applications for other materials and research themes, such as electron tomography sample preparation and new aperture design, are envisaged.

Researcher(s)

• Promoter: Schryvers Nick

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The aim of this research project is to apply state-of-the-art methods from the oprimal design of experiments in the field of elektron microscopy. These methods will allow electron microscopists to evaluate, to compare, and to optimize experiments in terms of the attainable precision with which structure parameters, the atom positions in particular, can be measured. Moreover, statistical experimental design provides the possibility to decide if new instrumental developments result in significantly higher attainable precisions. The highest attainable precision determines the theoretical limit to quantitative electron microscopy.

Researcher(s)

• Promoter: Van Dyck Dirk
• Co-promoter: Goos Peter
• Co-promoter: Van Aert Sandra

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

We aim to investigate two routes towards new materials by deposition of nanoclusters with a very specific composition and by using nanoclusters as building blocks in a so far unexplored process of self-assembly, namely the glancing angle deposition of nanoclusters. We will investigate the formation and growth processes, perform a thorough structural characterization of the nano-assembled films and study a number of key properties of these novel materials.

Researcher(s)

• Promoter: Van Tendeloo Staf

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Within this project we will study in a systematic way the relation between composition and structure versus the electronic and optical properties of transparent conducting oxides (TCO) by means of ab initio electronic structure calculations.

Researcher(s)

• Promoter: Lamoen Dirk
• Co-promoter: Partoens Bart

Research team(s)

• Electron microscopy for materials research (EMAT)

Project website

Project type(s)

• Research Project

Abstract

The main goal of this project is to develop discrete tomography for electron microscopy. As a starting point for the development of new reconstruction algorithms, the DART (Discrete Algebraic Reconstruction Technique) algorithm will be used. DART is an iterative algebraic reconstruction algorithm that is currently being developed at VISION LAB. It alternates between steps of the SIRT algorithm from continuous tomography and certian descretization steps. Within the SIRT iterations, subsets of the pixels are fixed at one of the constant grey levels, creating a new system of equations with fewer unknown than the original system.

Researcher(s)

• Promoter: Bals Sara
• Co-promoter: Batenburg Joost
• Co-promoter: Sijbers Jan

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

There are three main goals in this project: developing software, the optimization of the practical implementation of PED and the application of the new possibilities on the unrefined structures.

Researcher(s)

• Promoter: Hadermann Joke

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The aim of this project is to understand why yellowish films are formed during plasma cleaning of tarnished silver-copper alloys. The intensity of these films for alloys containing less than 97 w% of silver increases with the amount of copper in the alloy. In order to understand this phenomenon both sulphide layers and yellowish films will be analysed in detail.

Researcher(s)

• Promoter: Schryvers Nick
• Co-principal investigator: Storme Patrick
• Co-promoter: Janssens Koen

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The aim of this project is to realize a breakthrough toward quantitative, model-based electron microscopy so as to obtain precise measurements of physical structure parameters from the observations. From theoretical as well as from experimental point of view, this is the project's goal. On the one hand, this means that the methodology will be further improved and optimized and on the other hand, it will be shown that precise measurements are attainable in practice by applying the methodology to experimental observations.

Researcher(s)

• Promoter: Van Dyck Dirk
• Co-promoter: Van Tendeloo Staf
• Fellow: Van Aert Sandra

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The present project aims to investigate the micro- and atomic structure of the crystal lattices and defects occuring in one particular Ni-Ti alloy system in which Ni is gradually substituted by Pd. A set of alloys ranging from Ti50Ni45Pd5 to Ti5oNi25Pd25 will be prepared by arc melting followed by the necessary homogenization. The transformation temperatures will be determined by differential scanning calorimetry (DSC) and the effect of different heat treatments will be investigated by TEM.

Researcher(s)

• Promoter: Schryvers Nick

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The phase stability of Ge-Sb-Te alloys is investigated as a function of composition and temperature by means of ab initio electronic structure calculations, cluster expansions and data mining techniques. The presence of vacancies on the Ge/Sb sublattice is fully taken into account and for the ground state structures the optical properties are investigated through a calculation of the dielectric function.

Researcher(s)

• Promoter: Lamoen Dirk

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The project targets to understand the growth of complex oxide thin films by a detailed characterisation and modelling of the process. The relaxation between a number of layer properties and intrinsic properties of the layers will be evaluated.

Researcher(s)

• Promoter: Van Tendeloo Staf

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The project targets to understand the growth of complex oxide thin films by a detailed characterisation and modelling of the process. The relaxation between a number of layer properties and intrinsic properties of the layers will be evaluated.

Researcher(s)

• Promoter: Bogaerts Annemie

Research team(s)

• Plasma Lab for Applications in Sustainability and Medicine - Antwerp (PLASMANT)
• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The Condor project will take up research on the model driven development of systems that are governed by complex physics and have to comply with severe performance requirements. it will concentrate on systems that - incorporate intricate and delicately interrelated physics; - are very sensitive to implementation details and imperfections and to external disturbances.

Researcher(s)

• Promoter: Van Dyck Dirk
• Co-promoter: Van Aert Sandra

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The goal of this project is the development of X-ray software-diffractometer complex for crystalline materials quality control in industry (cement production, metallurgy, extractive industries etc.). The software is based on Rietveld method and enables quantitative control of crystalline mixtures and amorphous component.

Researcher(s)

• Promoter: Hadermann Joke

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Strength and deformability of polycrystalline metals are determined by phenomena at various length scales. At a scale which we would label "nanoscopic", dislocations are created and pushed forward by the applied stress, achieving plastic deformation at the nano-scale. At the micro-scale, large numbers of moving dislocations interact and organize themselves in complex patterns. Still at higher scales, massive collective behaviour of these dislocations and patterns allow the plastic deformation of entire grains. On their turn they interact with each other finally leading to a certain mechanical response of the material at the macroscopic scale (i.e., the smallest scale at which it can be looked upon as a continuous medium). The response of the material on applied stresses depends on all these phenomena. Events on the various length scales may also cause important changes in the material, such as microstructure, internal damage and mechanical properties (strength and ductility). Note that the role of dislocations can partially be taken over by mechanical twinning or other stress-induced phase transformations. All this has been extensively studies on all these length scales. These studies certainly do have there merits, and have led to important experimental observations and theoretical understanding of the material behaviour at these length scales. However, in recent years it has become strikingly clear the events of each length scale do influence the events on other length scales, and that more significant progress in the understand (and modelling) of the material behaviour may be achieved by studying these relations than by further refining knowledge on each relevant length scale separately. Finally, strong size effects occur when structural dimensions such as for instance film thickness or grain size starts interacting with the dislocation mean free path or the dislocation cell size, revealing a completely new and almost unexplored physics. On first sight, polymer based, fibre reinforced composite materials seem to belong to a quite different world than polycrystalline metals. And yet, much of what has been said above also applies to these materials. Strength and residual deformability depend on the initiation and further development of damage at the micro-scale. Also here the microscopic events have been seriously studied and modelled, but the study of the coupling with the material behaviour at the macroscopic level (called meso-scopic level by experts in composite materials) is still in its infancy. It did not yet lead to satisfactory generic understanding (and modelling) for the case of general multi-axial straining, so the presents applicants believe that important synergy can be achieved doing the research on metals and composite materials in a collaborative way. Much has to be gained from transferring, when physically relevant, methods and models developed in the metal area to the composite polymer area, and vice-versa. The engineering motivation for looking at these phenomena involves the development of higher performance materials, the optimisation of the manufacturing operations, and the improvement of the design and integrity assessment methods for both traditional (transport, energy) and emerging (MeMS, multifunctional active panels) structures.

Researcher(s)

• Promoter: Schryvers Nick

Research team(s)

• Electron microscopy for materials research (EMAT)

Project website

Project type(s)

• Research Project

Abstract

The aim of this project is to bridge the gap between art and science. The starting point is the atomic world and the world of nanotechnology as observed through the electron microscope. Dork Vander Eecken will use these observations as his inspiration source for his graphical work. The project will result in a comon book and portfolio where art and science will touch each other. Iit is the aim to inspire young artists through lectures and workshops.

Researcher(s)

• Promoter: Van Tendeloo Staf

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Tendeloo Staf

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Tendeloo Staf

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

During the last 20 years, a strong evolution can be observed in the demands that are imposed on microscopic and nanoscopic characterization methods. Newly developed materials are becoming increasingly complex with respect to their chemical composition and structure on the micro/nanoscopic level. This has been the driving force for recent and spectacular developments in the world of transmission electron microscopy (TEM). Besides the race towards a better resolution using aberration corrected microscopes, directly interpretable results are obtained using advanced techniques such as exit wave reconstruction and high angular annular dark field scanning transmission electron microscopy (HAADF-STEM). However, these techniques have often been used to obtain results in well known systems such as Si and Au. Most technological applications however require much more complex materials. Apparently, applying the techniques mentioned above in order to solve problems relevant for solid state physics is not straightforward. This challenge forms the goal of our project.

Researcher(s)

• Promoter: Van Tendeloo Staf
• Fellow: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This project is dedicated to the structural and chemical characterization of diamond like carbon (DLC) coatings, thus supporting the optimization of the coating structure. By using different types of imaging as well as analytical techniques in (scanning) transmission electron microscopy the following question are aimed to be answered: (i) how are the crystallites distributed in the amorphous matrix, (ii) to what extent occurs coalescence between individual crystallites, (iii) how far are the crystallites separated from each other, and (iv) what is the influence of the deposition parameters on the chemical bonding between crystallites and amorphous matrix. These questions will be answered by structurally and chemically characterizing the coatings on different length scales; from the (sub-)micrometer scale down to the atomic scale.

Researcher(s)

• Promoter: Erni Rolf

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This project represents a formal research agreement between UA and on the other hand EU. UA provides EU research results mentioned in the title of the project under the conditions as stipulated in this contract.

Researcher(s)

• Promoter: Van Tendeloo Staf

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The low competitiveness of Peru is one of the major development problems of the County. One of the important causes of the low competitiveness is the lack of a solid scientific and technical capacity in the county that can allow the creation of the research - development - innovation chain. Mining & metallurgy is the main activity of the country, it provides the 50% of the county revenues; however no research activity is developed in this sector relthed to materials characterization and products are basically exported as raw material without added value. The current project aims to contribute in the establishment of a research group with an intemàtional level in electron microscopy for materials research with emphasis in nanoscience. The Group will operate at PC-TIM and ]PEN improving the Peruvian scientific production through the publication of scientific & technical papers and training students and professionals in research activities at international standard levels. At the end of the project we expect to have a critical number of researchers in order to make sustainable the research activities in the field, As collateral mid term result, it is expected that the research team will gain prestige and credibility in order to pay attention from the national industry, deserving financial support for research and educational activities.

Researcher(s)

• Promoter: Van Dyck Dirk
• Co-promoter: Van Tendeloo Staf

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This project represents a research contract awarded by the University of Antwerp. The supervisor provides the Antwerp University research mentioned in the title of the project under the conditions stipulated by the university.

Researcher(s)

• Promoter: Van Tendeloo Staf
• Co-promoter: Hadermann Joke
• Co-promoter: Schryvers Nick
• Co-promoter: Van Dyck Dirk
• Co-promoter: Verbeeck Johan
• Fellow: Abakumov Artem
• Fellow: Erni Rolf

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Tendeloo Staf

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This project aims to measure inelastic interactions of fast electrons with plasmons in order to obtain phaserelations. It combines two well known techniques in electron microscopy: electron energy loss spectroscopy and electron holography. Traditional electron holography operates with elastically scattered electrons to obtain phase information of the exit wave near the object. In this project, we will use holography to obtain the phase relations in experiments with inelastic electrons. In this case, the reference wave traditionally used in holography needs to be replaces by a beam which underwent the same inelastic excitation in order to still have some coherence between reference wave and exit wave near the sample. In the theoretical part of this project we study the inelastic interaction of electrons with plasmon and how this can be linked to the experiments. We make use of the time dependent Hartree Fock aproach. This theory uses the equations of motion aproach of the general density matrix (essentially the Fourier transform of the MDFF). Special attention is put to the off-diagonal elements of the density matrix that contain information on correlation and coherence which can be closely linked to the experimental results.

Researcher(s)

• Promoter: Verbeeck Johan
• Co-promoter: Brosens Fons

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Tendeloo Staf
• Co-promoter: Bogaerts Annemie
• Co-promoter: Peeters Francois

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

A first goal of the project is to extend the knowledge on the complicated relationships between the chemical composition, crystal structure, local structure, electronic correlations and magnetic properties of complex oxides. As a second goal we want to develop modern synthesis paths towards new materials based on complex transition metal oxides with promising practical properties, in particular colossal magnetoresistance (CMR). The main steps to achieve this will be the synthesis of new compounds, the detailed structural investigation with various diffraction techniques including transmission electron microscopy (TEM), X-ray diffraction (XRD) and neutron diffraction (ND), and the characterization of the physical properties by magnetic and electric transport measurements. The choice of possible systems for investigation was based on crystal chemistry considerations, on known relationships between the crystal structure and the properties and on existing analogies with complex oxides of other transition metals.

Researcher(s)

• Promoter: Van Tendeloo Staf
• Co-promoter: Hadermann Joke

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Tendeloo Staf

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Nanostructured superconductors play an important role in nanoscience since they provide a unique opportunity to apply quantum-mechanical principles to obtain specific superconducting properties needed for applications, by using nanoscale confinement of the condensate and flux to modify and control the coherent quantum ensembles of correlated eIectrons or holes responsible for the appearance of superconductivity. Designing specific material properties through the application of quantum mechanical principles is "quantum design" - a key idea in nanoscience. Superconductors, with their inherent quantum coherence over even macroscopie scale are in that respect superior to semiconductors, magnetic or normal metallic nanomaterials, where quantum coherence is much more difficult to achieve. In that respect nanostructured superconductors is the best choice for the demonstration of applicability of quantum design to tailor specific properties of materials at nanoscale. The two key properties: the absence of resistance to the dc current flow and quantum coherence of the condensate make superconductors extremely promising materials for nano-technologies and for various applications in micro- and nano-electronics, electrotechnics and as ultra-sensitive field, current and voltage sensors. Due to an intrinsic coherence of the condensate, superconducting eIements are primary candidates for developing physical realizations of the qubits for quantum computing. The possibiIities of the practical applications of superconducting materials, however, are limited by their critical parameters: temperature, field, and current. Remarkably, superconductors are materials where an artificial nanoscale modulation cao drasticalIy improve their critical parameters. In this project, we wilI study the size dependence of the superconducting properties and the critical parameters and we wilI investigate the electron pairing correlations at the nanometer scale.

Researcher(s)

• Promoter: Van Tendeloo Staf
• Co-promoter: Peeters Francois

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Tendeloo Staf

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Dyck Dirk
• Co-promoter: Lamoen Dirk
• Fellow: Jorissen Kevin

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Tendeloo Staf
• Fellow: Olenev Andrei

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The study of surfaces, interfaces, microscopic and even nanoscopic structures becomes more and more important in the characterization of very diverse materials in metallurgy, microelectronics, optoelectronics, photographic sciences etc. This characterization is mostly carried out using so-called (micro)beam techniques. By interaction of a "primary" beam (electrons, photons, ions), "secondary" signals are generated at the material's surface (electrons, photons, ions, neutrals), which contain information on the composition and/or structure of the material's surface. The various techniques differ in the kind of information, i.e. information depth, depth resolution, possibility to measure depth profiles, lateral resolution, compatibility with certain types of materials (electrical insulator vs. conductor, refractory vs. labile material), destructive or non-destructive character and type of information (elemental, istopic, molecular) It is clear that one method cannot answer all questions. Moreover, the required equipment is very expensive It is not possible for one research group to have in-house all infrastructure, accessories, know-how, know-why, and experienced personnel. Cooperation is therefore a must. The scientific research community aims at facilitating mutual consultations, exchanges and access to complementary equipment for solving a variety of problems, introduced by one or more of its members.

Researcher(s)

• Promoter: Schryvers Nick
• Co-promoter: Van Grieken Rene
• Co-promoter: Van Tendeloo Staf

Research team(s)

• Electron microscopy for materials research (EMAT)
• Plasma Lab for Applications in Sustainability and Medicine - Antwerp (PLASMANT)

Project type(s)

• Research Project

Abstract

In spite of a long tradition of international research many aspects, especially quantitative ones, of the functional properties of (NiTi- ) shape memory alloys are not explained or understood. The origin of this is probably the fact that the increasing commercial success of those alloys, especially in the medical business, has driven the research to application optimalisation rather than to seek for the fundamental origin of the observations. This became very clear during a recent finished EU-craft and a EU-Growth project in which recovery stresses of constrained elements and wires had to be optimized without explaining why the given treatments gave different results. So, it is evident that the absence of a fundamental understanding of a lot of experimental observations hampers the optimal use of shape memory alloy. Based on those experiences, our international recognition in the field of shape memory alloys and the long term experience with NiTi alloys, a fundamental project is proposed which should lead to the understanding of the mechanical, physical and thermodynamic relationship between microstructure and functional properties, as function of the thermo- mechanical history, the composition and the applied temperatures.

Researcher(s)

• Promoter: Schryvers Nick

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The aim of the project is to realize a breakthrough toward quantitative atomic resolution electron tomography in order to measure the local, three-dimensional structure of aperiodic materials as precisely as possible. For the validation of theoretical models, a precision of the atom positions of the order of 0.01 to 0.001 nm is required.

Researcher(s)

• Promoter: Van Dyck Dirk
• Co-promoter: Van Aert Sandra

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The aim of the suggested research project is the computation and measurement of electron scattering data in ternary semiconductors, needed for accurate compositional analysis of semiconductor nanostructures such as In(x)Ga(1-x)As quantum wells and quantum dots by high resolution transmission electron microscopy. The planned research project is a collaboration between an experimental group (EMA T, Electronenmicroscopie voor Materiaalonderzoek) and a theory group (TSM, Theoretical Study of Matter) of the University of Antwerp. The goal of the project is twofold. First, structure amplitudes, Debye-Waller factors and static displacement effects will be computed theoretically for technologically interesting materials such as e.g. InGaAs, AIGaAs, GaAsSb, CdZnSe and CdZnS. Second, intensities of diffracted beams will be measured in these materials and compared with our theoretical data. In this way, we aim at providing more reliable data for structure amplitudes and Debye-Waller factors. Our research will improve the accuracy of composition determination in ternary semiconductor nanostructures, and will provide accurate data for any quantitative transmission electron microscopy investigation of these materials. Furthermore, methods developed for theoretical calculation of structure amplitudes and Debye-Waller factors will be applicable to almost any type of material. Therefore, this work will make a substantial contribution to improved quantitative analysis of transmission electron micrographs in general.

Researcher(s)

• Promoter: Lamoen Dirk

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The idea of this project is to break the myth that art and science (in the broad sense) are totally independent worlds. It is our idea that art and science can mutually and positively influence each other. This was the case for e.g. Da Vinci and Escher; there is no reason why this should not happen today. This project wants to bring different forms of art and science closer together.

Researcher(s)

• Promoter: Van Tendeloo Staf

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Many current problems in advanced functional materials are related to the large range of length and time scales involved in the phase transformations that occur in them. In order to understand the details of the behaviour of such materials and ultimately to put this understanding to use in advanced applications, we need to bridge this multitude of scales by appropriate schemes of interconnected theoretical approaches. The quality and usefulness of these theories have to be tested through comparison with well designed experiments on a series of typical materials, chosen for their relevance to the scientific and engineering communities. The proposed network will address these problems in a highly multidisciplinary way, involving scientists from applied mathematical groups as well as theoretical and experimental solid state physicists. Moreover, the combination of teams forms a geographically representative picture of the relevant research in Europe, including groups from East-Europe, Mediterranean countries and less-favoured regions and is supported by a US team consisting of exceptional researchers. Although recently contacts between these different communities have increased, the variety and complexity of the different approaches still requires special training and transfer of knowledge opportunities for early stage as well as experienced researchers to ensure new and continuing cross-talk between their members. The training and transfer of knowledge will be organised by setting up a scheme of exchange procedures combining in-house training with individual secondments, dedicated courses, schools and workshops. The totality of these exchanges will be overviewed by a training steering committee. The average ratio between early stage and experienced researchers is 48/36 yielding a perfect combination between stability and flexibility. The research is organised into four general objectives. The first combines all characterisation techniques and defines the concrete model systems chosen for the experiments, such as shape memory materials, ferroelectrics and materials with enhanced magnetoresistance. The three others deal with generic theoretical and numerical approaches to phase transformations and related aspects. The identified tasks imply strong collaborations between different teams.

Researcher(s)

• Promoter: Schryvers Nick

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Many current problems in advanced functional materials are related to the large range of length and time scales involved in the phase transformations that occur in them. In order to understand the details of the behaviour of such materials and ultimately to put this understanding to use in advanced applications, we need to bridge this multitude of scales by appropriate schemes of interconnected theoretical approaches. The quality and usefulness of these theories have to be tested through comparison with well designed experiments on a series of typical materials, chosen for their relevance to the scientific and engineering communities. The proposed network will address these problems in a highly multidisciplinary way, involving scientists from applied mathematical groups as well as theoretical and experimental solid state physicists. Moreover, the combination of teams forms a geographically representative picture of the relevant research in Europe, including groups from East-Europe, Mediterranean countries and less-favoured regions and is supported by a US team consisting of exceptional researchers. Although recently contacts between these different communities have increased, the variety and complexity of the different approaches still requires special training and transfer of knowledge opportunities for early stage as well as experienced researchers to ensure new and continuing cross-talk between their members. The training and transfer of knowledge will be organised by setting up a scheme of exchange procedures combining in-house training with individual secondments, dedicated courses, schools and workshops. The totality of these exchanges will be overviewed by a training steering committee. The average ratio between early stage and experienced researchers is 48/36 yielding a perfect combination between stability and flexibility. The research is organised into four general objectives. The first combines all characterisation techniques and defines the concrete model systems chosen for the experiments, such as shape memory materials, ferroelectrics and materials with enhanced magnetoresistance. The three others deal with generic theoretical and numerical approaches to phase transformations and related aspects. The identified tasks imply strong collaborations between different teams.

Researcher(s)

• Promoter: Schryvers Nick

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The goal of the network is to revitalize actinide research and to ensure the highest level of expertise in Europe through the dissemination of knowledge and the organization of education and training activities. The research activities of the participating partners will be brought together and a strong collaboration between the laboratories will be organized e.g. through the exchange of scientists. The network aims at making nuclear research more attractive to young scientists.

Researcher(s)

• Promoter: Lamoen Dirk

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The partners involved in this project aim at knowledge development with economic finality in the area of molecular separation and catalysis. This knowledge development will be based on a new material concept and will be implemented in a broad range of applications. The new concept concerns the development of a generation of catalysts, adsorbents and membranes using the directed assembly of nanoblocks into a variety of macroscopic materials under influence of supramolecular forces. This project further aims at the development of reliable and suitable instruments for computer supported innovation, evaluation of new chemical processes and catalysts, membranes or adsorbents.

Researcher(s)

• Promoter: Van Tendeloo Staf

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The project aims to study the relation between the chemical composition of blue and purple enamels, of the substrate glass they are applied upon and the wheathering processes these materials are subject to, that are part of historical stained glass windows.

Researcher(s)

• Promoter: Schryvers Nick
• Co-promoter: Cornelis Etienne
• Co-promoter: Van Dyck Dirk

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Because of their microporosity, zeolite materials play an important role in a number of molecular processes such as heterogeneous catalysis, molecular separation, adsorption and ion exchange. Materials with a fixed porosity are also important for other applications, such as molecular electronics, non-linear optics and biochemistry. Most zeolites are based on silica and alumina. Traditionally the synthesis of zeolites takes place with the hydrothermal gel method. When the hydrogel is heated, the zeolite crystals nucleate and grow till micron size particles. The selectivity for the crystallisation of the requested zeolite is favoured by adding the appropriate organic structure directing molecules called "templates", which occupy the pore volumes. The microporosity is obtained by evacuation of these template molecules from the inorganic framework. Nanoplates are organic-inorganic hybrid particles with a strong tendency to self organisation. By adding the secondary template molecule the initial self organisation is perturbed and a new organisation is introduced. The aim of this project is to try to understand the interaction mechanism between nanoslabs as well as the interaction with secondary templates. If we can do so, we can try to interfere and make 'customer-made' hierarchic materials. The first level of organisation is at the level of the individual nanoslabs, which form the zeolite structure. The second level is the coupling between these slabs according specific rules which give rise to a chracteristic mesoporosity. The second goal is then to synthesise new hierarchic materials and to characterise their physical and chemical properties.

Researcher(s)

• Promoter: Van Tendeloo Staf

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Tendeloo Staf
• Co-promoter: Schryvers Nick

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Dyck Dirk
• Fellow: Van Aert Sandra

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Ceramic thin films have attracted great interest since they exhibit a rich spectrum of physical properties (e.g. ferromagnetism, colossal magnetoresistance and superconductivity). The nature of these properties is determined by very small characteristic length scales. Up till now, high-resolution transmission electron microscopy (HRTEM) was considered as the standard technique to study the atomic structure of thin films. However, the analysis of HRTEM images is hampered by aberrations of the electromagnetic lens system. Another disadvantage of "classical" microscopy is the fact that only intensity (=(amplitude)2), can be recorded and therefore, an essential part of the electron wave, being the phase, is lost. Different techniques have been developed to solve the above-mentioned problems and two of them will be used in this project: the "focus variation" technique and "off-axis electron holography". Up till now, these methodes were only used in experiments in which the structure of the materials was already know. Therefore, the challenge of this project is to use quantitative HRTEM in the study of nanosystems and systems in which local (tiny) structural changes influence their properties. Atom positions near interfaces and defects may deviate from their ideal positions. However, these small changes can have a large influence on the physical properties of the materials. The intention of this project is to determine atom positions (or strain) near planar discontinuities (substrate-film interfaces, crystal defects, ...) in nanostructured materials with a precision of 5-10 pm. In practise, the experiments will primary use superconducting (La-Sr)CuO4 thin films on a LaSrAlO4 substrate and (La-Sr)MnO3 CMR materials, deposited on different substrates.

Researcher(s)

• Promoter: Van Tendeloo Staf
• Fellow: Bals Sara

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Due to its exceptional physical properties, GaN is a promising semiconductor material for use in both electro-optical devices (LEDs, LDs) and electronic devices (high power, high frequency transistors). The production of GaN based structures remains however difficult, mainly by the lack of a decent substrate. On top, GaN shows piezo-electrical properties which makes that device characteristics are very sensitive to changes in the strain state of the material. Transmission electron microscopy (TEM) is applied to obtain structural and chemical information of GaN (test) structures on an (sub)nanometre scale. This information is very often necessary to explain physical properties of the (test)structures.

Researcher(s)

• Promoter: Van Tendeloo Staf
• Fellow: Van Daele Benny

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Dyck Dirk
• Fellow: Jorissen Kevin

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Tendeloo Staf
• Fellow: Abakumov Artem

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The main aim of this project is -to clarify the role of low energetic bombardment by unbalanced magnetron sputtering on adhesion, microstructure, grain boundaries and orientation of thin films. -to obtain a strong preferential orientation in/out of the plane for cubic oxides, metallic and semiconducting materials -to determine the correlation between microstructure and growth mechanism of thin films.

Researcher(s)

• Promoter: Van Tendeloo Staf

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This project will measure the short and long term stabilities of the electrical sources in a tranmission electron microscope, in order to optimise their performance. With an active feedback loop, the instabilities will be reduced. The project will focus on the high tension source, which is directly related to the stability of the energy axis in EELS mode, but the equipment is chosen to be flexible enough to study other sources of instabilities like lens current sources and temperature.

Researcher(s)

• Promoter: Verbeeck Johan

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Hadermann Joke

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Tendeloo Staf

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Tendeloo Staf

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Tendeloo Staf

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Hadermann Joke
• Co-promoter: Van Tendeloo Staf

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This Scientific Research Network of the FWO-Vlaanderen brings brings together several research groups active in the field of Density Functional Theory.

Researcher(s)

• Promoter: Lamoen Dirk

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Tendeloo Staf

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This project aims at the optimisation of the methodology of the simultaneous determination of the electronic and atomic structure and the chemical composition and speciation of nano configurations in a single instrument. The required instrumentation is already available at EMAT (Electron Microscopy for Materials Research) within two different electron microscopes, but the optimal registration of the data and the interpretation of the results still require an integrated effort from various research areas. The above-mentioned nano-structural aspects are of utmost importance for the physical and chemical properties of many materials rendering this fundamental research project a gateway to several novel technological applications. The data sets that will be treated will be acquired using two high resolution transmission electron microscopes (HRTEM) (3000F ARP, CM30 UT), equipped with a field emission gun (FEG) and an electron energy loss spectrometer (EELS) with an energy filter (EF) and CCD detector. The first instrument also has a high resolution scanning transmission unit (STEM) and energy dispersive X-ray detector (EDX). Both instruments provide the possibility to work in nanoprobe, by which spectroscopic information of extremely small volumes can be obtained. The emphasis of the present project is on the optimisation of the acquiring and interpretation of EELS results in combination with other techniques. The fine structure of the spectra can give information on the chemical state and environment enabling the so-called speciation of the elements. In order to reach the extreme detail aimed for, the working conditions of both instruments have to be secured to minimise external influences. The possibility to record the information directly in a digital way via different detectors and CCD cameras implies a strongly enhanced and useful quantitative output. To make this project feasible and successful different domains of expertise available at the UA are brought together: HRTEM and EELS detection (EMAT) and interpretation with respect to chemical speciation (MiTAC) for materials science and the research of image and data improvement (Visielab). In the framework of this project three model systems will be investigated with the objective of optimising the performance of the various possibilities of the instrumentation. Apart from the structural characterisation, particular attention will be paid to the EELS methodology from which chemical as well as electronic information can be extracted. As a first system thin films of La1-xSr xMnO3 (CMR : Colossal Magnetic Resistance)-material in which various valency-states of Mn-ions can disintegrate on a nanometer scale will be examined. This demixing can only be visualised by the differences in the fine-structure of the EELS-spectra (ELNES) of the different states. A second system concerns diamond-like carbon films (DLC) produced by plasma enhanced chemical vapour deposition (PE-CVD). In these films one wants to discriminate the different types of carbon bonds depending on the plasma conditions. Again, especially ELNES will provide the necessary information. In the third model system nanoprecipitates in a known silicon or germanium matrix will be characterised. These precipitates are known from high resolution studies in EMAT but the structure and contents could up to now not unambiguously be determined because no chemical information, e.g. on the presence of oxygen, was available at the required nanoscale. Again the nanoprobe EELS-data should supply the required information for a thorough structure analysis including the speciation of the elements. In a later stage of the project the developed methods and acquired know-how will open possibilities for the study of nano-configurations and interfaces in materials which are more complex than the chosen model systems.

Researcher(s)

• Promoter: Schryvers Nick
• Co-promoter: Scheunders Paul
• Co-promoter: Van Espen Piet
• Co-promoter: Van Landuyt Joseph

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Tendeloo Staf
• Co-promoter: Van Dyck Dirk
• Fellow: Geuens Philippe

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Tendeloo Staf

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The recent evolution from microtechnology to nanotechnology only increases the importance of transmission electron micrsocopy. The idea is to quantify not only the sub 0.2 nm high resolution electron microsocopy, but also the local energy electron loss spectra.

Researcher(s)

• Promoter: Van Tendeloo Staf
• Co-promoter: Van Dyck Dirk
• Co-promoter: Van Landuyt Joseph

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Different aspects of symmetry breaking phase transitions in crystalline materials are investigated by theoretical models which are compared with experimental results.

Researcher(s)

• Promoter: Schryvers Nick

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project