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Author Xia, C.; Pedrazo-Tardajos, A.; Wang, D.; Meeldijk, J.D.; Gerritsen, H.C.; Bals, S.; de Donega, C.M. url  doi
openurl 
  Title Seeded growth combined with cation exchange for the synthesis of anisotropic Cu2-xS/ZnS, Cu2-xS, and CuInS2 nanorods Type A1 Journal article
  Year 2021 Publication Chemistry of materials Abbreviated Journal  
  Volume 33 Issue 1 Pages 102-116  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Colloidal copper(I) sulfide (Cu2-xS) nanocrystals (NCs) have attracted much attention for a wide range of applications because of their unique optoelectronic properties, driving scientists to explore the potential of using Cu2-xS NCs as seeds in the synthesis of heteronanocrystals to achieve new multifunctional materials. Herein, we developed a multistep synthesis strategy toward Cu2-xS/ZnS heteronanorods. The Janus-type Cu2-xS/ZnS heteronanorods are obtained by the injection of hexagonal high-chalcocite Cu2-xS seed NCs in a hot zinc oleate solution in the presence of suitable surfactants, 20 s after the injection of sulfur precursors. The Cu2-xS seed NCs undergo rapid aggregation and coalescence in the first few seconds after the injection, forming larger NCs that act as the effective seeds for heteronucleation and growth of ZnS. The ZnS heteronucleation occurs on a single (100) facet of the Cu2-xS seed NCs and is followed by fast anisotropic growth along a direction that is perpendicular to the c-axis, thus leading to Cu2-xS/ZnS Janus-type heteronanorods with a sharp heterointerface. Interestingly, the high-chalcocite crystal structure of the injected Cu2-xS seed NCs is preserved in the Cu2-xS segments of the heteronanorods because of the highthermodynamic stability of this Cu2-xS phase. The Cu2-xS/ZnS heteronanorods are subsequently converted into single-component Cu2-xS and CuInS2 nanorods by postsynthetic topotactic cation exchange. This work expands the possibilities for the rational synthesis of colloidal multicomponent heteronanorods by allowing the design principles of postsynthetic heteroepitaxial seeded growth and nanoscale cation exchange to be combined, yielding access to a plethora of multicomponent heteronanorods with diameters in the quantum confinement regime.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000610984700009 Publication Date 2020-12-28  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited 10 Open Access OpenAccess  
  Notes C.X. acknowledges China Scholarship Council (CSC) for the financial support (grant number 201406330055). C.d.M.D. acknowledges funding from the European Commission for access to the EMAT facilities (grant number EUSMI E180900184). D.W. acknowledges an Individual Fellowship funded by the Marie Sklodowska-Curie Actions (MSCA) in Horizon 2020 program (grant 894254 SuprAtom). S.B. acknowledges support by means of the ERC Consolidator grant no. 815128 REALNANO. The authors thank Donglong Fu for XRD measurements.; sygma Approved (up) Most recent IF: NA  
  Call Number UA @ admin @ c:irua:176587 Serial 6732  
Permanent link to this record
 

 
Author Fatermans, J.; de Backer, A.; den Dekker, A.J.; Van Aert, S. pdf  doi
isbn  openurl
  Title Atom column detection Type H2 Book chapter
  Year 2021 Publication Advances in imaging and electron physics T2 – Advances in imaging and electron physics Abbreviated Journal  
  Volume Issue Pages 177-214  
  Keywords H2 Book chapter; Electron microscopy for materials research (EMAT); Vision lab  
  Abstract By combining statistical parameter estimation and model-order selection using a Bayesian framework, the maximum a posteriori (MAP) probability rule is proposed in this chapter as an objective and quantitative method to detect atom columns from high-resolution scanning transmission electron microscopy (HRSTEM) images. The validity and usefulness of this approach is demonstrated to both simulated and experimental annular dark-field (ADF) STEM images, but also to simultaneously acquired annular bright-field (ABF) and ADF STEM image data.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos Publication Date 2021-03-06  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume 217 Series Issue Edition  
  ISSN ISBN 978-0-12-824607-8; 1076-5670 Additional Links UA library record  
  Impact Factor Times cited Open Access Not_Open_Access  
  Notes ERC Consolidator project funded by the European Union grant #770887 Picometrics Approved (up) Most recent IF: NA  
  Call Number UA @ admin @ c:irua:177531 Serial 6775  
Permanent link to this record
 

 
Author de Backer, A.; Fatermans, J.; den Dekker, A.J.; Van Aert, S. pdf  doi
isbn  openurl
  Title Atom counting Type H2 Book chapter
  Year 2021 Publication Advances in imaging and electron physics T2 – Advances in imaging and electron physics Abbreviated Journal  
  Volume Issue Pages 91-144  
  Keywords H2 Book chapter; Electron microscopy for materials research (EMAT); Vision lab  
  Abstract In this chapter, a statistical model-based method to count the number of atoms of monotype crystalline nanostructures from high-resolution annular dark-field (ADF) scanning transmission electron microscopy (STEM) images is discussed in detail together with a thorough study on the possibilities and inherent limitations. We show that this method can be applied to nanocrystals of arbitrary shape, size, and atom type. The validity of the atom-counting results is confirmed by means of detailed image simulations and it is shown that the high sensitivity of our method enables us to count atoms with single atom sensitivity.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos Publication Date 2021-03-06  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume 217 Series Issue Edition  
  ISSN ISBN 978-0-12-824607-8; 1076-5670 Additional Links UA library record  
  Impact Factor Times cited Open Access Not_Open_Access  
  Notes ERC Consolidator project funded by the European Union grant #770887 Picometrics Approved (up) Most recent IF: NA  
  Call Number UA @ admin @ c:irua:177529 Serial 6776  
Permanent link to this record
 

 
Author de Backer, A.; Fatermans, J.; den Dekker, A.J.; Van Aert, S. pdf  doi
isbn  openurl
  Title Efficient fitting algorithm Type H2 Book chapter
  Year 2021 Publication Advances in imaging and electron physics T2 – Advances in imaging and electron physics Abbreviated Journal  
  Volume Issue Pages 73-90  
  Keywords H2 Book chapter; Electron microscopy for materials research (EMAT)  
  Abstract An efficient model-based estimation algorithm is introduced to quantify the atomic column positions and intensities from atomic-resolution (scanning) transmission electron microscopy ((S)TEM) images. This algorithm uses the least squares estimator on image segments containing individual columns fully accounting for overlap between neighboring columns, enabling the analysis of a large field of view. To provide end-users with this well-established quantification method, a user friendly program, StatSTEM, is developed which is freely available under a GNU public license. In this chapter, this efficient algorithm is applied to three different nanostructures for which the analysis of a large field of view is required.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos Publication Date 2021-03-06  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume 217 Series Issue Edition  
  ISSN ISBN 978-0-12-824607-8; 1076-5670 Additional Links UA library record  
  Impact Factor Times cited Open Access Not_Open_Access  
  Notes ERC Consolidator project funded by the European Union grant #770887 Picometrics Approved (up) Most recent IF: NA  
  Call Number UA @ admin @ c:irua:177528 Serial 6778  
Permanent link to this record
 

 
Author de Backer, A.; Fatermans, J.; den Dekker, A.J.; Van Aert, S. pdf  doi
isbn  openurl
  Title General conclusions and future perspectives Type H2 Book chapter
  Year 2021 Publication Advances in imaging and electron physics T2 – Advances in imaging and electron physics Abbreviated Journal  
  Volume Issue Pages 243-253  
  Keywords H2 Book chapter; Electron microscopy for materials research (EMAT); Vision lab  
  Abstract This chapter provides an overview of statistical and quantitative methodologies that have pushed (scanning) transmission electron microscopy ((S)TEM) toward accurate and precise measurements of unknown structure parameters for understanding the relation between the structure of a material and its properties. Hereby, statistical parameter estimation theory has extensively been used which enabled not only measuring atomic column positions, but also quantifying the number of atoms, and detecting atomic columns as accurately and precisely as possible from experimental images. As a general conclusion, it can be stated that advanced statistical techniques are ideal tools to perform quantitative electron microscopy at the atomic scale. In the future, statistical methods will continue to be developed and novel quantification procedures will open up new possibilities for studying material structures at the atomic scale.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos Publication Date 2021-03-06  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume 217 Series Issue Edition  
  ISSN ISBN 978-0-12-824607-8; 1076-5670 Additional Links UA library record  
  Impact Factor Times cited Open Access Not_Open_Access  
  Notes ERC Consolidator project funded by the European Union grant #770887 Picometrics Approved (up) Most recent IF: NA  
  Call Number UA @ admin @ c:irua:177533 Serial 6781  
Permanent link to this record
 

 
Author Fatermans, J.; de Backer, A.; den Dekker, A.J.; Van Aert, S. pdf  doi
isbn  openurl
  Title Image-quality evaluation and model selection with maximum a posteriori probability Type H2 Book chapter
  Year 2021 Publication Advances in imaging and electron physics T2 – Advances in imaging and electron physics Abbreviated Journal  
  Volume Issue Pages 215-242  
  Keywords H2 Book chapter; Electron microscopy for materials research (EMAT); Vision lab  
  Abstract The maximum a posteriori (MAP) probability rule for atom column detection can also be used as a tool to evaluate the relation between scanning transmission electron microscopy (STEM) image quality and atom detectability. In this chapter, a new image-quality measure is proposed that correlates well with atom detectability, namely the integrated contrast-to-noise ratio (ICNR). Furthermore, the working principle of the MAP probability rule is described in detail showing a close relation to the principles of model-selection methods.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos Publication Date 2021-03-06  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume 217 Series Issue Edition  
  ISSN ISBN 978-0-12-824607-8; 1076-5670 Additional Links UA library record  
  Impact Factor Times cited Open Access Not_Open_Access  
  Notes ERC Consolidator project funded by the European Union grant #770887 Picometrics Approved (up) Most recent IF: NA  
  Call Number UA @ admin @ c:irua:177532 Serial 6782  
Permanent link to this record
 

 
Author de Backer, A.; Fatermans, J.; den Dekker, A.J.; Van Aert, S. pdf  doi
isbn  openurl
  Title Introduction Type H2 Book chapter
  Year 2021 Publication Advances in imaging and electron physics T2 – Advances in imaging and electron physics Abbreviated Journal  
  Volume Issue Pages 1-28  
  Keywords H2 Book chapter; Electron microscopy for materials research (EMAT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos Publication Date 2021-03-06  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume 217 Series Issue Edition  
  ISSN ISBN 978-0-12-824607-8; 1076-5670 Additional Links UA library record  
  Impact Factor Times cited Open Access Not_Open_Access  
  Notes ERC Consolidator project funded by the European Union grant #770887 Picometrics Approved (up) Most recent IF: NA  
  Call Number UA @ admin @ c:irua:177525 Serial 6784  
Permanent link to this record
 

 
Author de Backer, A.; Fatermans, J.; den Dekker, A.J.; Van Aert, S. pdf  doi
isbn  openurl
  Title Optimal experiment design for nanoparticle atom counting from ADF STEM images Type H2 Book chapter
  Year 2021 Publication Advances in imaging and electron physics T2 – Advances in imaging and electron physics Abbreviated Journal  
  Volume Issue Pages 145-175  
  Keywords H2 Book chapter; Electron microscopy for materials research (EMAT); Vision lab  
  Abstract In this chapter, the principles of detection theory are used to quantify the probability of error for atom counting from high-resolution scanning transmission electron microscopy (HRSTEM) images. Binary and multiple hypothesis testing have been investigated in order to determine the limits to the precision with which the number of atoms in a projected atomic column can be estimated. The probability of error has been calculated when using STEM images, scattering cross-sections or peak intensities as a criterion to count atoms. Based on this analysis, we conclude that scattering cross-sections perform almost equally well as images and perform better than peak intensities. Furthermore, the optimal STEM detector design can be derived for atom counting using the expression of the probability of error. We show that for very thin objects the low-angle annular dark-field (LAADF) regime is optimal and that for thicker objects the optimal inner detector angle increases.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos Publication Date 2021-03-06  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume 217 Series Issue Edition  
  ISSN ISBN 978-0-12-824607-8; 1076-5670 Additional Links UA library record  
  Impact Factor Times cited Open Access Not_Open_Access  
  Notes ERC Consolidator project funded by the European Union grant #770887 Picometrics Approved (up) Most recent IF: NA  
  Call Number UA @ admin @ c:irua:177530 Serial 6785  
Permanent link to this record
 

 
Author de Backer, A.; Fatermans, J.; den Dekker, A.J.; Van Aert, S. pdf  doi
isbn  openurl
  Title Statistical parameter estimation theory : principles and simulation studies Type H2 Book chapter
  Year 2021 Publication Advances in imaging and electron physics T2 – Advances in imaging and electron physics Abbreviated Journal  
  Volume Issue Pages 29-72  
  Keywords H2 Book chapter; Electron microscopy for materials research (EMAT); Vision lab  
  Abstract In this chapter, the principles of statistical parameter estimation theory for a quantitative analysis of atomic-resolution electron microscopy images are introduced. Within this framework, electron microscopy images are described by a parametric statistical model. Here, parametric models are introduced for different types of electron microscopy images: reconstructed exit waves, annular dark-field (ADF) scanning transmission electron microscopy (STEM) images, and simultaneously acquired ADF and annular bright-field (ABF) STEM images. Furthermore, the Cramér-Rao lower bound (CRLB) is introduced, i.e. a theoretical lower bound on the variance of any unbiased estimator. This CRLB is used to quantify the precision of the structure parameters of interest, such as the atomic column positions and the integrated atomic column intensities.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos Publication Date 2021-03-06  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume 217 Series Issue Edition  
  ISSN ISBN 978-0-12-824607-8; 1076-5670 Additional Links UA library record  
  Impact Factor Times cited Open Access Not_Open_Access  
  Notes ERC Consolidator project funded by the European Union grant #770887 Picometrics Approved (up) Most recent IF: NA  
  Call Number UA @ admin @ c:irua:177527 Serial 6788  
Permanent link to this record
 

 
Author Skorikov, A. openurl 
  Title Fast approaches for investigating 3D elemental distribution in nanomaterials Type Doctoral thesis
  Year 2021 Publication Abbreviated Journal  
  Volume Issue Pages 143 p.  
  Keywords Doctoral thesis; Electron microscopy for materials research (EMAT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos Publication Date  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved (up) Most recent IF: NA  
  Call Number UA @ admin @ c:irua:178855 Serial 6795  
Permanent link to this record
 

 
Author van der Jeught, S.; Muyshondt, P.G.G.; Lobato, I. url  doi
openurl 
  Title Optimized loss function in deep learning profilometry for improved prediction performance Type A1 Journal article
  Year 2021 Publication JPhys Photonics Abbreviated Journal  
  Volume 3 Issue 2 Pages 024014  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Single-shot structured light profilometry (SLP) aims at reconstructing the 3D height map of an object from a single deformed fringe pattern and has long been the ultimate goal in fringe projection profilometry. Recently, deep learning was introduced into SLP setups to replace the task-specific algorithm of fringe demodulation with a dedicated neural network. Research on deep learning-based profilometry has made considerable progress in a short amount of time due to the rapid development of general neural network strategies and to the transferrable nature of deep learning techniques to a wide array of application fields. The selection of the employed loss function has received very little to no attention in the recently reported deep learning-based SLP setups. In this paper, we demonstrate the significant impact of loss function selection on height map prediction accuracy, we evaluate the performance of a range of commonly used loss functions and we propose a new mixed gradient loss function that yields a higher 3D surface reconstruction accuracy than any previously used loss functions.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000641030000001 Publication Date 2021-03-18  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2515-7647 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited Open Access OpenAccess  
  Notes Approved (up) Most recent IF: NA  
  Call Number UA @ admin @ c:irua:178171 Serial 6797  
Permanent link to this record
 

 
Author Arslan Irmak, E.; Liu, P.; Bals, S.; Van Aert, S. pdf  url
doi  openurl
  Title 3D Atomic Structure of Supported Metallic Nanoparticles Estimated from 2D ADF STEM Images: A Combination of Atom – Counting and a Local Minima Search Algorithm Type A1 Journal article
  Year 2021 Publication Small methods Abbreviated Journal Small Methods  
  Volume Issue Pages 2101150  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract Determining the three-dimensional (3D) atomic structure of nanoparticles (NPs) is critical to understand their structure-dependent properties. It is hereby important to perform such analyses under conditions relevant for the envisioned application. Here, we investigate the 3D structure of supported Au NPs at high temperature, which is of importance to understand their behavior during catalytic reactions. To overcome limitations related to conventional high-resolution electron tomography at high temperature, 3D characterization of NPs with atomic resolution has been performed by applying atom-counting using atomic resolution annular darkfield scanning transmission electron microscopy (ADF STEM) images followed by structural relaxation. However, at high temperatures, thermal displacements, which affect the ADF STEM intensities, should be taken into account. Moreover, it is very likely that the structure of a NP investigated at elevated temperature deviates from a ground state configuration, which is difficult to determine using purely computational energy minimization approaches. In this paper, we therefore propose an optimized approach using an iterative local minima search algorithm followed by molecular dynamics (MD) structural relaxation of candidate structures associated with each local minimum. In this manner, it becomes possible to investigate the 3D atomic structure of supported NPs, which may deviate from their ground state configuration.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000716511600001 Publication Date 2021-11-10  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2366-9608 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited 12 Open Access OpenAccess  
  Notes This work was supported by the European Research Council (Grant 815128 REALNANO to SB, Grant 770887 PICOMETRICS to SVA, Grant 823717 ESTEEM3). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project funding (G.0267.18N, G.0502.18N, G.0346.21N).; sygmaSB; esteem3jra; esteem3reported Approved (up) Most recent IF: NA  
  Call Number EMAT @ emat @c:irua:183289 Serial 6820  
Permanent link to this record
 

 
Author Herzog, M.J.; Gauquelin, N.; Esken, D.; Verbeeck, J.; Janek, J. url  doi
openurl 
  Title Increased Performance Improvement of Lithium-Ion Batteries by Dry Powder Coating of High-Nickel NMC with Nanostructured Fumed Ternary Lithium Metal Oxides Type A1 Journal article
  Year 2021 Publication ACS applied energy materials Abbreviated Journal ACS Appl. Energy Mater.  
  Volume 4 Issue 9 Pages 8832-8848  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract Dry powder coating is an effective approach to protect the surfaces of layered cathode active materials (CAMs) in lithium-ion batteries. Previous investigations indicate an incorporation of lithium ions in fumed Al2O3, ZrO2, and TiO2 coatings on LiNi0.7Mn0.15Co0.15O2 during cycling, improving the cycling performance. Here, this coating approach is transferred for the first time to fumed ternary LiAlO2, Li4Zr3O8, and Li4Ti5O12 and directly compared with their lithium-free equivalents. All materials could be processed equally and their nanostructured small aggregates accumulate on the CAM surfaces to quite homogeneous coating layers with a certain porosity. The LiNixMnyCozO2 (NMC) coated with lithium-containing materials shows an enhanced improvement in overall capacity, capacity retention, rate performance, and polarization behavior during cycling, compared to their lithium-free analogues. The highest rate performance was achieved with the fumed ZrO2 coating, while the best long-term cycling stability with the highest absolute capacity was obtained for the fumed LiAlO2-coated NMC. The optimal coating agent for NMC to achieve a balanced system is fumed Li4Ti5O12, providing a good compromise between high rate capability and good capacity retention. The coating agents prevent CAM particle cracking and degradation in the order LiAlO2 ≈ Al2O3 > Li4Ti5O12 > Li4Zr3O8 > ZrO2 > TiO2. A schematic model for the protection and electrochemical performance enhancement of high-nickel NMC with fumed metal oxide coatings is sketched. It becomes apparent that physical and chemical characteristics of the coating significantly influence the performance of NMC. A high degree of coating-layer porosity is favorable for the rate capability, while a high coverage of the surface, especially in vulnerable grain boundaries, enhances the long-term cycling stability and improves the cracking behavior of NMCs. While zirconium-containing coatings possess the best chemical properties for high rate performances, aluminum-containing coatings feature a superior chemical nature to protect high-nickel NMCs.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000703338600018 Publication Date 2021-09-27  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2574-0962 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited 15 Open Access OpenAccess  
  Notes For his support in scanning electron microscopy analysis, the authors thank Erik Peldszus. N. G. and J. V. acknowledge funding from GOA project “Solarpaint” of the University of Antwerp and from the Flemish Research Fund (FWO) project G0F1320N. The Qu-Ant-EM microscope and the direct electron detector were partly funded by the Hercules fund from the Flemish Government Approved (up) Most recent IF: NA  
  Call Number EMAT @ emat @c:irua:183949 Serial 6823  
Permanent link to this record
 

 
Author Pedrazo Tardajos, A. openurl 
  Title Advanced graphene supports for 3D in situ transmission electron microscopy Type Doctoral thesis
  Year 2021 Publication Abbreviated Journal  
  Volume Issue Pages 247 p.  
  Keywords Doctoral thesis; Electron microscopy for materials research (EMAT)  
  Abstract Transmission electron microscopy (TEM) is an ideal tool to investigate nanomaterials. The information from TEM experiments allows us to link the structure and composition of nanomaterials to their intrinsic physical properties. However, despite the significant evolution of the TEM field during the last two decades, major progress is still possible through the development of optimal TEM techniques and supports. The results presented in this thesis focus on the optimization of sample supports and their application. Among the different options, graphene has previously been reported as useful sample support for electron microscopy due to its unparalleled properties, for example, it is the thinnest known support and provides a protective effect to the sample under investigation. Unfortunately, commercial graphene grids show poor quality, in terms of intactness and cleanness, inhibiting their wide application within the field. Therefore, this thesis focuses on the application of optimized graphene TEM grids, obtained by transferring high quality graphene using an advanced procedure. This improvement on the transfer has enabled the visualization of materials with low contrast and high sensitivity towards the electron beam, such as surface ligands capping gold nanoparticles or metal halide perovskites. Furthermore, the implemented protocol is not only of interest for conventional TEM grids but also a major benefit for in situ TEM studies, where the sample is investigated in real time under certain stimuli. Hence, the same graphene transfer technology can be also applied to advanced in situ MEMS holders dedicated for both heating and gas experiments, where the thickness and insulating nature of the silicon nitride (Si3N4) support may hamper some applications. By engineering periodic arrays of holes in their Si3N4 membrane by focused ion beam, onto which the graphene is transferred, it has been possible to get proof-of-concept 3D in situ investigations of heat-induced morphological and compositional transformations of complex nanosystems. As an example, it has enabled the investigation of the possible phase-transition of metal halide perovskites upon heating using 2D and 3D structural characterization. Moreover, it has allowed the study of in situ three-dimensional nanoparticle dynamics during gas phase catalysis as well as the first steps that would lead towards the design and creation of the first Graphene Gas Cell. Consequently, implementation of the advanced graphene transfer technology described in this thesis is envisaged to impact a broad range of future experiments.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos Publication Date  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved (up) Most recent IF: NA  
  Call Number UA @ admin @ c:irua:181143 Serial 6836  
Permanent link to this record
 

 
Author Skorikov, A.; Heyvaert, W.; Albrecht, W.; Pelt, D.M.; Bals, S. doi  openurl
  Title EMAT Simulated 3D Nanoparticle Structures Dataset Type Dataset
  Year 2021 Publication Abbreviated Journal  
  Volume Issue Pages  
  Keywords Dataset; Electron microscopy for materials research (EMAT)  
  Abstract This dataset contains 1000 simulated nanoparticle-like 3D structures and noisy EDX-like elemental maps based on them. These data are intended to be used for quantitative analysis of data processing methods in (EDX) tomography of nanoparticles and training the data-driven approaches for these tasks. The dataset is structured as follows: voxel_data/clean 3D voxel grid representation of the simulated nanoparticles. Voxel intensities are adjusted so that the total intensity equals 103. All 3D structures have unique identifiers in 0..999 range. The data derived from a 3D structure preserves this unique identifier. sinograms/clean Tilt series of projection images obtained from the corresponding 3D structures over an angular range of -75..75 degrees with a tilt step of 10 degrees to simulate a typical tilt series used in EDX tomography. Total intensity in each projection image equals 103. sinograms/noisy Tilt series of projection images corrupted with Poisson noise and an additional spatially uniform background noise. projections/clean Projection images extracted from the clean tilt series at 0 degrees tilt angle. projections/noisy Projection images extracted from the noisy tilt series at 0 degrees tilt angle. images/clean Visualizations of the clean projections as PNG images with the intensity range adjusted to 0..255 images/noisy Visualizations of the noisy projections as PNG images with the intensity range adjusted to 0..255  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos Publication Date  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access Not_Open_Access  
  Notes Approved (up) Most recent IF: NA  
  Call Number UA @ admin @ c:irua:180615 Serial 6838  
Permanent link to this record
 

 
Author Abakumov, A.M.; Li, C.; Boev, A.; Aksyonov, D.A.; Savina, A.A.; Abakumova, T.A.; Van Tendeloo, G.; Bals, S. pdf  doi
openurl 
  Title Grain boundaries as a diffusion-limiting factor in lithium-rich NMC cathodes for high-energy lithium-ion batteries Type A1 Journal article
  Year 2021 Publication ACS applied energy materials Abbreviated Journal  
  Volume 4 Issue 7 Pages 6777-6786  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract High-energy lithium-rich layered transition metal oxides are capable of delivering record electrochemical capacity and energy density as positive electrodes for Li-ion batteries. Their electrochemical behavior is extremely complex due to sophisticated interplay between crystal structure, electronic structure, and defect structure. Here we unravel an extra level of this complexity by revealing that the most typical representative Li1.2Ni0.13Mn0.54Co0.13O2 material, prepared by a conventional coprecipitation technique with Na2CO3 as a precipitating agent, contains abundant coherent (001) grain boundaries with a Na-enriched P2-structured block due to segregation of the residual sodium traces. The trigonal prismatic oxygen coordination of Na triggers multiple nanoscale twinning, giving rise to incoherent (104) boundaries. The cationic layers at the (001) grain boundaries are filled with transition metal cations being Mn-depleted and Co-enriched; this makes them virtually not permeable for the Li+ cations, and therefore they negatively influence the Li diffusion in and out of the spherical agglomerates. These results demonstrate that besides the mechanisms intrinsic to the crystal and electronic structure of Li-rich cathodes, their rate capability might also be depreciated by peculiar microstructural aspects. Dedicated engineering of grain boundaries opens a way for improving inherently sluggish kinetics of these materials.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000678382900042 Publication Date 2021-07-02  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2574-0962 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited 4 Open Access OpenAccess  
  Notes We thank Dr. M. V. Berekchiian (MSU) for assisting in ICPMS measurements. We acknowledge Russian Science Foundation (Grant 20-43-01012) and Research Foundation Flanders (FWO Vlaanderen, Project No. G0F1320N) for financial support. Approved (up) Most recent IF: NA  
  Call Number UA @ admin @ c:irua:180556 Serial 6841  
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Author Du, K. url  openurl
  Title In situ TEM study on the manipulation of ferroelectrics Type Doctoral thesis
  Year 2021 Publication Abbreviated Journal  
  Volume Issue Pages 91 p.  
  Keywords Doctoral thesis; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract The strong correlated oxide systems attract a lot of attentions of scientists recently, the coexistence and interplay between various degrees of freedom, such as charge, spin and orbital, has been demonstrated to induce some fancy physical properties and phenomenon, including metal-insulator transition, high temperature superconductivity, colossal magnetoresistance. As a part of the strong correlated oxide systems, the ferroelectrics is abundant in both physical properties and application. First, if the electric dipole continuously rotating around a stable core then a topological structure is produced. If people could manipulate the topological structure and simultaneously observe the structure evolution, with external field applied on the topological structure, then it is very likely for such kind of ferroelectrics to be the next generation of storage, for it is reported to need low power input and produce high density of storage. In the other hand, in solids, charge polarity can one-to-one correspond to spin polarity phenomenologically, such as ferroelectricity and ferromagnetism, antiferroelectricity and antiferromagnetism, but ferrielectricity and ferrimagnetism kept telling a disparate story in microscopic level. The claimed “ferrielectrics” in existing research is equivalent to ferroelectric ones, thus the findings of such a real irreducible solids would complete the last piece of the ferroelectrics family. While solving the above two questions remain challengeable: the size of topological structure is small (typically below 10 nm), general characterization methods are insufficient for such high demand on space resolution, not to mention manipulating and observing its dynamic behavior at an atomic level. Here, employing the spherical aberration corrected electron microscope, we applied external field (heating and bias) on ferroelectrics. Combined with high-end characterization methods including the high-angle annular dark field (HAADF-STEM) image, Electron Energy Loss Spectroscopy (EELS) and integrated differential phase contrast (iDPC), the dynamic evolution of ferroelectrics are observed and analyzed. The main findings of this paper could be concluded as listed here: (1) PbTiO3(001)// SrTiO3(001) is grown on DyScO3 and SrRuO3 by pusled laser deposition, the atomical EDS mapping results reveal that the interface between PTO and STO is atomically sharp. Increasing the thickness of PTO from 1 uc to 21 uc, the topological structure wihtin PTO layer would transform from a/c domain to wave, vortex and finally flux closure domain. The geometric phase analysis results (GPA) reveal that above topological structures are corresponding to various strain. (2) Combined with in-situ biasing holder, the electric bias was applied on polar vortex, and it evolved from vortex (0 V) to polar wave (2 V) and finally polar down (5 V). EELS analysis was performed and we find that negative charge is gathered at vortex core, which turns the Ti4+ to Ti3+ there. The oxygen vacancy at negative polarization surface and the negative charge at the positive polarization surface realized the polarization screening of polar down domain. (3) Through the atomic inspection and analysis on lattice structure of BaFe2Se3, the near ladders within single unit are found to be different in degree of tetramerization, thus leading to a residual polarization along the a-axis. The further in-situ heating and biasing experiment was conducted on BaFe2Se3, and the strong and weak ladders are proved to be independent for their behavior under external field. This findings distinguishes ferrielectrics from ferroelectrics in solids.  
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  ISSN ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved (up) Most recent IF: NA  
  Call Number UA @ admin @ c:irua:179310 Serial 6842  
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Author Prabhakara, V. url  openurl
  Title Strain measurement for semiconductor applications with Raman spectroscopy and Transmission electron microscopy Type Doctoral thesis
  Year 2021 Publication Abbreviated Journal  
  Volume Issue Pages 149 p.  
  Keywords Doctoral thesis; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract Scaling down the size of transistors has been a trend for several decades which has led to improved transistor performance, increased transistor density and hence the overall computation power of IC chips. The trend slowed in recent years due to reliability and power consumption issues at the nanoscale. Hence strain is introduced into transistor channels that has beneficial effects on improving the mobility of charge carriers, providing an alternative pathway for enhancing transistor performance. Therefore, monitoring strain is vital for the semiconductor industry. With the recent trend of decreasing device dimensions (FinFETS ~ 10-20nm) and strain modulation being used throughout, industry needs a reliable and fast method as quality control or defect characterisation. Such a universal strain measurement method does not exist, and one relies on a combination of quantitative in-line methods and complex off-line approaches. In this thesis, I investigated TEM and Raman spectroscopy-based methodologies for strain measurement. In terms of TEM methodologies, advancements are made for the STEM moiré imaging, targeting strain spatial resolution enhancement. I introduce advanced quadrature demodulation and phase stepping interferometry applied to STEM moiré that greatly enhances the spatial resolution while providing enhanced field of view and sensitivity for strain measurement. We introduce ways to reduce scan distortions in strain maps using an alternative scan strategy called “Block scanning” and the non-linear regression applied for strain extraction. Prospects for 3D strain analysis using high-resolution tomography is also investigated which gives direct access for the full second order strain tensors calculation. Finally, we compare strain measurements from TEM techniques with inline techniques like Raman spectroscopy. Raman stress measurement involves sensitive identification of the TO and LO phonon peaks. Raman spectrum of strained Ge transistor channel consists of strongly overlapping peaks within the spectral resolution of the spectrometer. Hence, the process of deconvolution of the two peaks is rather challenging. Hence, we explore new polarisation geometries like radially polarised incoming light which was shown to ease the deconvolution problem resulting in improved precision for Raman stress–strain measurements.  
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  Corporate Author Thesis  
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  Language Wos Publication Date  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved (up) Most recent IF: NA  
  Call Number UA @ admin @ c:irua:182261 Serial 6847  
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Author Zhang, Z.; Bourgeois, L.; Zhang, Y.; Rosalie, J.M.; Medhekar, N. url  doi
openurl 
  Title Advanced imaging and simulations of precipitate interfaces in aluminium alloys and their role in phase transformations Type P1 Proceeding
  Year 2020 Publication MATEC web of conferences T2 – 17th International Conference on Aluminium Alloys (ICAA), October 26-29, 2020 Abbreviated Journal  
  Volume Issue Pages 09003  
  Keywords P1 Proceeding; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract Precipitation is accompanied by the formation and migration of heterophase interfaces. Using the combined approach of advanced imaging and atomistic simulations, we studied the precipitate-matrix interfaces in various aluminium alloy systems, aiming to resolve their detailed atomic structures and illuminate their role in phase transformations.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000652552200053 Publication Date 2020-11-05  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume 326 Series Issue Edition  
  ISSN 2261-236x; 2274-7214 ISBN Additional Links UA library record; WoS full record  
  Impact Factor Times cited Open Access  
  Notes Approved (up) Most recent IF: NA  
  Call Number UA @ admin @ c:irua:179147 Serial 6851  
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Author Velazco Torrejón, A. url  openurl
  Title Alternative scan strategies for high resolution STEM imaging Type Doctoral thesis
  Year 2021 Publication Abbreviated Journal  
  Volume Issue Pages 131 p.  
  Keywords Doctoral thesis; Electron microscopy for materials research (EMAT)  
  Abstract Currently, a large variety of materials are studied by transmission electron microscopy (TEM) as it offers the possibility to perform structural and elemental analysis at a local scale. Relatively recent advances in aberration correctors and electron sources allow the instrument to achieve atomic resolution. Along with these advances, a state-of-the-art technology has been reached in TEM. However, the instrument is far from being perfect and imperfections or external sources can make the interpretation of information troublesome. Environmental factors such as acoustic and mechanical vibrations, temperature fluctuations, etc., can induce sample drift and create image distortions. These distortions are enhanced in scanning operation because of the serial acquisition of the information, which are more apparent at atomic resolution as small field of views are imaged. In addition, scanning distortions are induced due to the finite time response of the scan coils. These types of distortions would reduce precision in atomic-scale strain analysis, for instance, in semiconductors. Most of the efforts to correct these distortions are focused on data processing techniques post-acquisition. Another limitation in TEM is beam damage effects. Beam damage arises because of the energy transferred to the sample in electron-sample interactions. In scanning TEM, at atomic resolution, the increased electron charge density (electron dose) carried on a sub-Å size electron probe may aggravate beam damage effects. Soft materials such as zeolites, organic, biological materials, etc., can be destroyed under irradiation limiting the amount of information that can be acquired. Current efforts to circumvent beam damage are mostly based on low electron dose acquisitions and data processing methods to maximize the signal at low dose conditions. In this thesis, a different approach is given to address drift and scanning distortions, as well as beam damage effects. Novel scan strategies are proposed for that purpose, which are shown to substantially overcome these issues compared to the standard scan method in TEM.  
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  Language Wos Publication Date  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved (up) Most recent IF: NA  
  Call Number UA @ admin @ c:irua:180973 Serial 6852  
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Author Vervaet, B.A.; Nast, C.C.; Jayasumana, C.; Schreurs, G.; Roels, F.; Herath, C.; Kojc, N.; Samaee, V.; Rodrigo, S.; Gowrishankar, R. url  openurl
  Title Chronic interstitial nephritis in agricultural communities : a toxin-induced proximal tubular nephropathy Type A1 Journal article
  Year 2020 Publication European Medical Journal : Nephrology Abbreviated Journal  
  Volume 8 Issue 1 Pages 40-42  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Pathophysiology  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos Publication Date  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2053-4248 ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved (up) Most recent IF: NA  
  Call Number UA @ admin @ c:irua:180862 Serial 6858  
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Author Roegiers, J. file  openurl
  Title Development of combined photocatalytic and active carbon fiber technology for indoor air purification based on Multiphysics models Type Doctoral thesis
  Year 2021 Publication Abbreviated Journal  
  Volume Issue Pages XXX, 197 p.  
  Keywords Doctoral thesis; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Sustainable Energy, Air and Water Technology (DuEL)  
  Abstract Exposure to volatile organic compounds (VOCs) remains a major public health concern. Indoor VOC concentrations typically far exceed outdoor levels due to a variety of emission sources and the stringent insulation measures that are imposed today. Many attempts have been made to use photocatalysis for indoor air purification. In an ideal situation, photocatalysis is capable of complete mineralization of VOCs to H2O and CO2, without any byproduct formation. Moreover, the process can take place at standard atmospheric conditions, i.e. ambient temperature and atmospheric pressure. However, successful exploitation is still impeded due to low conversion efficiency, significant pressure loss (and hence a high energy consumption) and byproduct formation. In the first part of this thesis an attempt was made to tackles these problems by designing a novel type of photocatalytic (PCO) reactor. The PCO device consists of a cylindrical vessel filled with TiO2-coated glass tubes and equipped with UV fluorescence lamps. It was investigated in terms of fluid dynamics, coating properties, UV-light distribution and photocatalytic activity. Experimental data was later used to develop and calibrate a Multiphysics model. The model proved to be a useful tool for designing and upscaling the PCO reactor. Consequently, an optimized prototype reactor was constructed and tested according the CEN-EN-16846-1 standard for VOC removal. Although the prototype showed promising results for lab-scale conditions, it struggled with byproduct formation when purifying ppb-level VOCs. In the second part of this thesis, activated carbon adsorption was investigated in order to combine it with photocatalysis. Activated carbon fiber was opted for its fast kinetics, high adsorption capacity and thermo-electrical regeneration. The filter was studied in detail regarding the adsorption of polar and apolar VOCs at indoor air concentration levels and regeneration capabilities. Experimental data was used to develop a Multiphysics model for activated carbon adsorption as well. Consequently, a novel type of ACF filter was developed using the Multiphysics model, which was equipped with electrodes in the tips of the pleats for effective thermal regeneration. In the last part, the combination of both ACF and PCO was studied using a realistic case study. Based on the Multiphysics model, the feasibility of a so-called hybrid air purification device could be investigated. The Multiphysics model shows promising results for this hybrid PCO-ACF system and hence, a demo setup was constructed for future research.  
  Address  
  Corporate Author Thesis  
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  Language Wos Publication Date  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved (up) Most recent IF: NA  
  Call Number UA @ admin @ c:irua:181137 Serial 6860  
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Author Guzzinati, G.; Das, P.P.; Zompra, A., A.; Nicopoulos, S.; Verbeeck, J. doi  openurl
  Title Electron energy loss spectra of several organic compounds Type Dataset
  Year 2020 Publication Abbreviated Journal  
  Volume Issue Pages  
  Keywords Dataset; Electron microscopy for materials research (EMAT)  
  Abstract We placed crystals of different compounds to explore the possibility of fingerprinting them through EELS. Here are representative datasets of 7 different compounds: b-cyclodextrin hexacarboxy cyclohexane tannin TH-15 peptide TH-27 peptide two different forms of piroxicam The datasets were collected at EMAT, using a monochromated FEI Titan3 TEM, within the scope of an EUSMI request. More information as well as analysis methodologies adopted for the data are detailed in the paper: Das et al. “Reliable Characterization of Organic & Pharmaceutical Compounds with High Resolution Monochromated EEL Spectroscopy”, Polymers 2020, 12(7), 1434.  
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  Corporate Author Thesis  
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  Series Editor Series Title Abbreviated Series Title  
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  ISSN ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved (up) Most recent IF: NA  
  Call Number UA @ admin @ c:irua:180654 Serial 6866  
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Author De wael, A. url  openurl
  Title Model-based quantitative scanning transmission electron microscopy for measuring dynamic structural changes at the atomic scale Type Doctoral thesis
  Year 2021 Publication Abbreviated Journal  
  Volume Issue Pages xiv, 146 p.  
  Keywords Doctoral thesis; Electron microscopy for materials research (EMAT)  
  Abstract Nanomaterialen kunnen uiterst interessante eigenschappen vertonen voor een verscheidenheid aan veelbelovende toepassingen, gaande van zonnecrème tot batterijen voor elektrische auto’s. Een nanometer is een miljard keer kleiner dan een meter. Op deze schaal kunnen de materiaaleigenschappen volledig verschillen van bulkmaterialen op grotere schaal. Bovendien hangen de eigenschappen van nanomaterialen sterk af van hun exacte grootte en vorm. Kleine verschillen in de posities van de atomen, in de grootte-orde van een picometer (nog eens duizend maal kleiner dan een nanometer), kunnen de fysische eigenschappen al drastisch beïnvloeden. Daarom is een betrouwbare kwantificering van de atomaire structuur van kritisch belang om de evolutie naar materiaalontwerp mogelijk te maken en inzicht te verwerven in de relatie tussen de fysische eigenschappen en de structuur van nanomaterialen. Daarnaast kan de atomaire structuur van nanomaterialen ook veranderen in de loop van de tijd ten gevolge van verschillende fysische processen. Het onderzoek dat in deze thesis gepresenteerd wordt, maakt het mogelijk om de dynamische structuurveranderingen van nanomaterialen betrouwbaar te kwantificeren op atomaire schaal door gebruik te maken van raster transmissie elektronenmicroscopie (STEM). Ik heb dit gerealiseerd door methodes te ontwikkelen waarmee ik het aantal atomen “achter elkaar” kan tellen in elke atoomkolom van een nanomateriaal, en dit op basis van beelden opgenomen met een elektronenmicroscoop. Een belangrijk verschil met telmethodes voor de analyse van een enkel beeld is het schatten van de kans dat een atoomkolom atomen zal verliezen of bijkrijgen van het ene naar het andere beeld in de tijdreeks. Deze kwantitatieve methode kan het ontrafelen van de tijdsafhankelijke structuur-eigenschappen relatie van een nanomateriaal mogelijk maken, wat uiteindelijk kan leiden tot efficiënter design en productie van nanomaterialen voor innovatieve toepassingen.  
  Address  
  Corporate Author Thesis  
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  Language Wos Publication Date  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved (up) Most recent IF: NA  
  Call Number UA @ admin @ c:irua:179514 Serial 6870  
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Author Jannis, D. url  openurl
  Title Novel detection schemes for transmission electron microscopy Type Doctoral thesis
  Year 2021 Publication Abbreviated Journal  
  Volume Issue Pages iv, 208 p.  
  Keywords Doctoral thesis; Electron microscopy for materials research (EMAT)  
  Abstract Electron microscopy is an excellent tool which provides resolution down to the atomic scale with up to pm precision in locating atoms. The characterization of materials in these length scales is of utmost importance to answer questions in biology, chemistry and material science. The successful implementation of aberration-corrected microscopes made atomic resolution imaging relatively easy, this could give the impression that the development of novel electron microscopy techniques would stagnate and only the application of these instruments as giant magnifying tools would continue. This is of course not true and a multitude of problems still exist in electron microscopy. Two of such issues are discussed below. One of the biggest problems in electron microscopy is the presence of beam damage which occurs due the fact that the highly energetic incoming electrons have sufficient kinetic energy to change the structure of the material. The amount of damage induced depends on the dose, hence minimizing this dose during an experiment is beneficial. This minimizing of the total dose comes at the expense of more noise due to the counting nature of the electrons. For this reason, the implementation of four dimensional scanning transmission electron microscopy (4D STEM) experiments has reduced the total dose needed per acquisition. However, the current cameras used to measure the diffraction patterns are still two orders of magnitude slower than to the conventional STEM methods. Improving the acquisition speed would make the 4D STEM technique more feasible and is of utmost importance for the beam sensitive materials since less dose is used during the acquisition. In TEM there is not only the possibility to perform imaging experiments but also spectroscopic measurements. There are two frequently used methods: electron energy-loss spectroscopy (EELS) and energy dispersive x-ray spectroscopy (EDX). EELS measures the energy-loss spectrum of the incoming electron which gives information on the available excitations in the material providing elemental sensitivity. In EDX, the characteristic x-rays, arising from the decay of an atom which is initially excited due to the incoming electrons, are detected providing similar elemental analysis. Both methods are able to provide comparable elemental information where in certain circumstances one outperforms the other. However, both methods have a detection limit of approximately 100-1000 ppm which is not sufficient for some materials. In this thesis, two novel techniques which can make significant progress for the two problems discussed above.  
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  Corporate Author Thesis  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved (up) Most recent IF: NA  
  Call Number UA @ admin @ c:irua:182404 Serial 6872  
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Author Psilodimitrakopoulos, S.; Orekhov, A.; Mouchliadis, L.; Jannis, D.; Maragkakis, G.M.; Kourmoulakis, G.; Gauquelin, N.; Kioseoglou, G.; Verbeeck, J.; Stratakis, E. url  doi
openurl 
  Title Optical versus electron diffraction imaging of Twist-angle in 2D transition metal dichalcogenide bilayers Type A1 Journal article
  Year 2021 Publication npj 2D Materials and Applications Abbreviated Journal  
  Volume 5 Issue 1 Pages 77  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract Atomically thin two-dimensional (2D) materials can be vertically stacked with van der Waals bonds, which enable interlayer coupling. In the particular case of transition metal dichalcogenide (TMD) bilayers, the relative direction between the two monolayers, coined as twist-angle, modifies the crystal symmetry and creates a superlattice with exciting properties. Here, we demonstrate an all-optical method for pixel-by-pixel mapping of the twist-angle with a resolution of 0.55(degrees), via polarization-resolved second harmonic generation (P-SHG) microscopy and we compare it with four-dimensional scanning transmission electron microscopy (4D STEM). It is found that the twist-angle imaging of WS2 bilayers, using the P-SHG technique is in excellent agreement with that obtained using electron diffraction. The main advantages of the optical approach are that the characterization is performed on the same substrate that the device is created on and that it is three orders of magnitude faster than the 4D STEM. We envisage that the optical P-SHG imaging could become the gold standard for the quality examination of TMD superlattice-based devices.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000694849200001 Publication Date 2021-09-09  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2397-7132 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited 4 Open Access OpenAccess  
  Notes This research has been co-financed by the European Union and Greek national funds through the Operational Program Competitiveness, Entrepreneurship and Innovation, under the call European R & T Cooperation-Grant Act of Hellenic Institutions that have successfully participated in Joint Calls for Proposals of European Networks ERA NETS (National project code: GRAPH-EYE T8 Epsilon Rho Alpha 2-00009 and European code: 26632, FLAGERA). L.M., G.Ko. and G.Ki. acknowledge funding by the Hellenic Foundation for Research and Innovation (H.F.R.I.) under the “First Call for H.F.R.I. Research Projects to support Faculty members and Researchers and the procurement of high-cost research equipment grant” (Project No: HFRI-FM17-3034). GKi, S.P. and G.M.M. acknowledge funding from a research co-financed by Greece and the European Union (European Social Fund-ESF) through the Operational Programme “Human Resources Development, Education and Lifelong Learning 2014-2020” in the context of the project “Crystal quality control of two-dimensional materials and their heterostructures via imaging of their non-linear optical properties” (MIS 5050340)“. J.V acknowledges funding from FWO G093417N ('Compressed sensing enabling low dose imaging in transmission electron microscopy') from the Flanders Research Fund, EU. J.V. and N.G. acknowledge funding from the European Union under the Horizon 2020 programme within a contract for Integrating Activities for Advanced Communities No 823717-ESTEEM3. J.V. N.G. and A.O. acknowledge funding through a GOA project ”Solarpaint" of the University of Antwerp. Approved (up) Most recent IF: NA  
  Call Number UA @ admin @ c:irua:181610 Serial 6877  
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Author Samaeeaghmiyoni, V.; Cordier, P.; Demouchy, S.; Bollinger, C.; Gasc, J.; Mussi, A.; Schryvers, D.; Idrissi, H. doi  openurl
  Title Research data supporting for Stress-induced amorphization triggers deformation in the lithospheric mantle Type Dataset
  Year 2020 Publication Abbreviated Journal  
  Volume Issue Pages  
  Keywords Dataset; Electron microscopy for materials research (EMAT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos Publication Date  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved (up) Most recent IF: NA  
  Call Number UA @ admin @ c:irua:180668 Serial 6881  
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Author Barbiellini, B.; Kuriplach, J.; Saniz, R. url  doi
openurl 
  Title Study of rechargeable batteries using advanced spectroscopic and computational techniques Type Editorial
  Year 2021 Publication Condensed Matter Abbreviated Journal  
  Volume 6 Issue 3 Pages 26  
  Keywords Editorial; Electron microscopy for materials research (EMAT)  
  Abstract Improving the efficiency and longevity of energy storage systems based on Li- and Na-ion rechargeable batteries presents a major challenge. The main problems are essentially capacity loss and limited cyclability. These effects are due to a hierarchy of factors spanning various length and time scales, interconnected in a complex manner. As a consequence, and in spite of several decades of research, a proper understanding of the ageing process has remained somewhat elusive. In recent years, however, combinations of advanced spectroscopy techniques and first-principles simulations have been applied with success to tackle this problem. In this Special Issue, we are pleased to present a selection of articles that, by precisely applying these methods, unravel key aspects of the reduction-oxidation reaction and intercalation processes. Furthermore, the approaches presented provide improvements to standard diagnostic and characterisation techniques, enabling the detection of possible Li-ion flow bottlenecks causing the degradation of capacity and cyclability.  
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  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000699368400001 Publication Date 2021-07-26  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2410-3896 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited Open Access OpenAccess  
  Notes Approved (up) Most recent IF: NA  
  Call Number UA @ admin @ c:irua:181630 Serial 6890  
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Author Mallick, S.; Khalsa, G.; Kaaret, J.Z.; Zhang, W.; Batuk, M.; Gibbs, A.S.; Hadermann, J.; Halasyamani, P.S.; Benedek, N.A.; Hayward, M.A. url  doi
openurl 
  Title The influence of the 6s² configuration of Bi³+ on the structures of A ' BiNb₂O₇ (A ' = Rb, Na, Li) layered perovskite oxides Type A1 Journal article
  Year 2021 Publication Journal of the Chemical Society : Dalton transactions Abbreviated Journal  
  Volume 50 Issue 42 Pages 15359-15369  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Solid state compounds which exhibit non-centrosymmetric crystal structures are of great interest due to the physical properties they can exhibit. The 'hybrid improper' mechanism – in which two non-polar distortion modes couple to, and stabilize, a further polar distortion mode, yielding an acentric crystal structure – offers opportunities to prepare a range of novel non-centrosymmetric solids, but examples of compounds exhibiting acentric crystal structures stabilized by this mechanism are still relatively rare. Here we describe a series of bismuth-containing layered perovskite oxide phases, RbBiNb2O7, LiBiNb2O7 and NaBiNb2O7, which have structural frameworks compatible with hybrid-improper ferroelectricity, but also contain Bi3+ cations which are often observed to stabilize acentric crystal structures due to their 6s(2) electronic configurations. Neutron powder diffraction analysis reveals that RbBiNb2O7 and LiBiNb2O7 adopt polar crystal structures (space groups I2cm and B2cm respectively), compatible with stabilization by a trilinear coupling of non-polar and polar modes. The Bi3+ cations present are observed to enhance the magnitude of the polar distortions of these phases, but are not the primary driver for the acentric structure, as evidenced by the observation that replacing the Bi3+ cations with Nd3+ cations does not change the structural symmetry of the compounds. In contrast the non-centrosymmetric, but non-polar structure of NaBiNb2O7 (space group P2(1)2(1)2(1)) differs significantly from the centrosymmetric structure of NaNdNb2O7, which is attributed to a second-order Jahn-Teller distortion associated with the presence of the Bi3+ cations.  
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  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000706651100001 Publication Date 2021-10-05  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1477-9234 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited Open Access OpenAccess  
  Notes Approved (up) Most recent IF: NA  
  Call Number UA @ admin @ c:irua:182584 Serial 6893  
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Author Lezaack, M.B.; Hannard, F.; Zhao, L.; Orekhov, A.; Adrien, J.; Miettinen, A.; Idrissi, H.; Simar, A. pdf  doi
openurl 
  Title Towards ductilization of high strength 7XXX aluminium alloys via microstructural modifications obtained by friction stir processing and heat treatments Type A1 Journal article
  Year 2021 Publication Materialia Abbreviated Journal  
  Volume 20 Issue Pages 101248  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract High strength 7XXX aluminium series reach exceptional strength, higher than all other industrial aluminium alloys. However, they suffer from a lack of ductility compared to softer series. This work presents a procedure to improve the ductility of 7475 Al alloy in high strength condition, reaching a true fracture strain of 70% at full 500 MPa T6 yield strength. Using friction stir processing (FSP) and post-FSP heat treatments, 100% of industrial rolled material T6 yield stress is maintained but a 180% increase in fracture strain is measured for the processed material. This ductility improvement is studied by in-situ synchrotron X-ray tomography and is explained by the reduction of intermetallic particles size and the homogenization of their spatial distribution. Furthermore, the microstructure after FSP shows equiaxed refined grains which favour crack deviation as opposed to large cracks parallel to the elongated coarse grains in rolled plate. These results are paving the way to better formability and crashworthiness of 7XXX alloys.  
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  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000718127100006 Publication Date 2021-10-19  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2589-1529 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited Open Access Not_Open_Access  
  Notes Approved (up) Most recent IF: NA  
  Call Number UA @ admin @ c:irua:184145 Serial 6894  
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