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Author Jany, B.R.; Gauquelin, N.; Willhammar, T.; Nikiel, M.; van den Bos, K.H.W.; Janas, A.; Szajna, K.; Verbeeck, J.; Van Aert, S.; Van Tendeloo, G.; Krok, F. url  doi
openurl 
  Title Controlled growth of hexagonal gold nanostructures during thermally induced self-assembling on Ge(001) surface Type A1 Journal article
  Year 2017 Publication (up) Scientific reports Abbreviated Journal Sci Rep-Uk  
  Volume 7 Issue 7 Pages 42420  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Nano-sized gold has become an important material in various fields of science and technology, where control over the size and crystallography is desired to tailor the functionality. Gold crystallizes in the face-centered cubic (fcc) phase, and its hexagonal closed packed (hcp) structure is a very unusual and rare phase. Stable Au hcp phase has been reported to form in nanoparticles at the tips of some Ge nanowires. It has also recently been synthesized in the form of thin graphene-supported sheets which are unstable under electron beam irradiation. Here, we show that stable hcp Au 3D nanostructures with well-defined crystallographic orientation and size can be systematically created in a process of thermally induced self-assembly of thin Au layer on Ge(001) monocrystal. The Au hcp crystallite is present in each Au nanostructure and has been characterized by different electron microscopy techniques. We report that a careful heat treatment above the eutectic melting temperature and a controlled cooling is required to form the hcp phase of Au on a Ge single crystal. This new method gives scientific prospects to obtain stable Au hcp phase for future applications in a rather simple manner as well as redefine the phase diagram of Gold with Germanium.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000393940700001 Publication Date 2017-02-14  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2045-2322 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.259 Times cited 25 Open Access OpenAccess  
  Notes The authors gratefully acknowledge the financial support from the Polish National Science Center, grant no. DEC-2012/07/B/ST5/00906. N.G., G.V.T. and J.V. acknowledge the European Union (EU) Council under the 7th Framework Program (FP7) ERC Starting Grant 278510 VORTEX for support. The Research Foundation Flanders is acknowledged through project fundings (G.0374.13N, G.0368.15N, G.0369.15N) and for a Ph.D. research grant to K.H.W.v.d.B. The microscope was partly funded by the Hercules Fund from the Flemish Government. T.W. acknowledges the Swedish Research Council for an international postdoc grant. The research leading to these results has received funding from the European Union Seventh Framework Programme under Grant Agreement 312483–ESTEEM2 (Integrated Infrastructure Initiative–I3). Part of the research was carried out with equipment purchased with financial support from the European Regional Development Fund in the framework of the Polish Innovation Economy Operational Program (Contract No. POIG.02.01.00-12-023/08). Approved Most recent IF: 4.259  
  Call Number EMAT @ emat @ c:irua:140846UA @ admin @ c:irua:140846 Serial 4423  
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Author Hudry, D.; De Backer, A.; Popescu, R.; Busko, D.; Howard, I.A.; Bals, S.; Zhang, Y.; Pedrazo‐Tardajos, A.; Van Aert, S.; Gerthsen, D.; Altantzis, T.; Richards, B.S. pdf  url
doi  openurl
  Title Interface Pattern Engineering in Core‐Shell Upconverting Nanocrystals: Shedding Light on Critical Parameters and Consequences for the Photoluminescence Properties Type A1 Journal article
  Year 2021 Publication (up) Small Abbreviated Journal Small  
  Volume Issue Pages 2104441  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT)  
  Abstract Advances in controlling energy migration pathways in core-shell lanthanide (Ln)-based hetero-nanocrystals (HNCs) have relied heavily on assumptions about how optically active centers are distributed within individual HNCs. In this article, it is demonstrated that different types of interface patterns can be formed depending on shell growth conditions. Such interface patterns are not only identified but also characterized with spatial resolution ranging from the nanometer- to the atomic-scale. In the most favorable cases, atomic-scale resolved maps of individual particles are obtained. It is also demonstrated that, for the same type of core-shell architecture, the interface pattern can be engineered with thicknesses of just 1 nm up to several tens of nanometers. Total alloying between the core and shell domains is also possible when using ultra-small particles as seeds. Finally, with different types of interface patterns (same architecture and chemical composition of the core and shell domains) it is possible to modify the output color (yellow, red, and green-yellow) or change (improvement or degradation) the absolute upconversion quantum yield. The results presented in this article introduce an important paradigm shift and pave the way toward the emergence of a new generation of core-shell Ln-based HNCs with better control over their atomic-scale organization.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000710758000001 Publication Date 2021-10-25  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1613-6810 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 8.643 Times cited 17 Open Access OpenAccess  
  Notes The authors would like to acknowledge the financial support provided by the Helmholtz Recruitment Initiative Fellowship (B.S.R.) and the Helmholtz Association's Research Field Energy (Materials and Technologies for the Energy Transition program, Topic 1 Photovoltaics and Wind Energy). The authors would like to thank the Karlsruhe Nano Micro Facility (KNMF) for STEM access. This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 Research and Innovation Programme (Grant agreement no. 770887 PICOMETRICS to S.V.A. and Grant agreement no. 815128 REALNANO to S.B.). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through Projects no. G.0502.18N, G.0267.18N, and a postdoctoral grant to A.D.B. T.A. acknowledges funding from the University of Antwerp Research fund (BOF). This project had received funding (EUSMI proposal #E181100205) from the European Union's Horizon 2020 Research and Innovation Programme under Grant agreement no 731019 (EUSMI). D.H. would like to thank “CGFigures” for helpful tutorials on 3D graphics with Blender.; sygmaSB Approved Most recent IF: 8.643  
  Call Number EMAT @ emat @c:irua:183285 Serial 6817  
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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 (up) 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 Most recent IF: NA  
  Call Number EMAT @ emat @c:irua:183289 Serial 6820  
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Author De Backer, A.; Zhang, Z.; van den Bos, K.H.W.; Bladt, E.; Sánchez‐Iglesias, A.; Liz‐Marzán, L.M.; Nellist, P.D.; Bals, S.; Van Aert, S. url  doi
openurl 
  Title Element Specific Atom Counting at the Atomic Scale by Combining High Angle Annular Dark Field Scanning Transmission Electron Microscopy and Energy Dispersive X‐ray Spectroscopy Type A1 Journal article
  Year 2022 Publication (up) Small methods Abbreviated Journal Small Methods  
  Volume Issue Pages 2200875  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract A new methodology is presented to count the number of atoms in multimetallic nanocrystals by combining energy dispersive X-ray spectroscopy (EDX) and high angle annular dark field scanning transmission electron microscopy (HAADF STEM). For this purpose, the existence of a linear relationship between the incoherent HAADF STEM and EDX images is exploited. Next to the number of atoms for each element in the atomic columns, the method also allows quantification of the error in the obtained number of atoms, which is of importance given the noisy nature of the acquired EDX signals. Using experimental images of an Au@Ag core–shell nanorod, it is demonstrated that 3D structural information can be extracted at the atomic scale. Furthermore, simulated data of an Au@Pt core–shell nanorod show the prospect to characterize heterogeneous nanostructures with adjacent atomic numbers.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000862072700001 Publication Date 2022-09-30  
  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 12.4 Times cited 5 Open Access OpenAccess  
  Notes This work was supported by the European Research Council (Grant 770887 PICOMETRICS to S.V.A., Grant 815128 REALNANO to S.B., and Grant 823717 ESTEEM3). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0267.18N, G.0502.18N, G.0346.21N) and a postdoctoral grant to A.D.B.; esteem3reported; esteem3JRA Approved Most recent IF: 12.4  
  Call Number EMAT @ emat @c:irua:191570 Serial 7109  
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Author Molina-Luna, L.; Duerrschnabel, M.; Turner, S.; Erbe, M.; Martinez, G.T.; Van Aert, S.; Holzapfel, B.; Van Tendeloo, G. pdf  doi
openurl 
  Title Atomic and electronic structures of BaHfO3-doped TFA-MOD-derived YBa2Cu3O7−δthin films Type A1 Journal article
  Year 2015 Publication (up) Superconductor science and technology Abbreviated Journal Supercond Sci Tech  
  Volume 28 Issue 28 Pages 115009  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Tailoring the properties of oxide-based nanocomposites is of great importance for a wide range of materials relevant for energy technology. YBa2Cu3O7−δ (YBCO) superconducting thin films containing nanosized BaHfO3 (BHO) particles yield a significant improvement of the magnetic flux pinning properties and a reduced anisotropy of the critical current density. These films were prepared by chemical solution deposition (CSD) on (100) SrTiO3 (STO) substrates yielding critical current densities up to 3.6 MA cm−2 at 77 K and self-field. Transport in-field J c measurements demonstrated a high pinning force maximum of around 6 GN/m3 for a sample annealed at T = 760 °C that has a doping of 12 mol% of BHO. This sample was investigated by scanning transmission electron microscopy (STEM) in combination with electron energy-loss spectroscopy (EELS) yielding strain and spectral maps. Spherical BHO nanoparticles of 15 nm in size were found in the matrix, whereas the particles at the interface were flat. A 2 nm diffusion layer containing Ti was found at the YBCO (BHO)/STO interface. Local lattice deformation mapping at the atomic scale revealed crystal defects induced by the presence of both sorts of BHO nanoparticles, which can act as pinning centers for magnetic flux lines. Two types of local lattice defects were identified and imaged: (i) misfit edge dislocations and (ii) Ba-Cu-Cu-Ba stacking faults (Y-248 intergrowths). The local electronic structure and charge transfer were probed by high energy resolution monochromated electron energy-loss spectroscopy. This technique made it possible to distinguish superconducting from non-superconducting areas in nanocomposite samples with atomic resolution in real space, allowing the identification of local pinning sites on the order of the coherence length of YBCO (~1.5 nm) and the determination of 0.25 nm dislocation cores.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000366193000018 Publication Date 2015-09-25  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0953-2048;1361-6668; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.878 Times cited 4 Open Access  
  Notes The authors thank financial support from the European Union under the Framework 6 program as a contract for an Integrated Infrastructure Initiative (References No. 026019 ESTEEM) and by the EUFP6 Research Project “NanoEngineered Superconductors for Power Applications” NESPA no. MRTN-CT-2006-035619. This work was supported by funding from the European Research Council under the Seventh Framework Programme (FP7). L.M.L, S.T. and G.V.T acknowledge ERC grant N°246791 – COUNTATOMS and funding under a contract for an Integrated Infrastructure Initiative, Reference No. 312483- ESTEEM2, as well as the EC project EUROTAPES. G.T.M. and S.V.A acknowledge financial support from the Fund for Scientific Research-Flanders (Reference G.0064.10N and G.0393.11N). M.D. acknowledges financial support from the LOEWE research cluster RESPONSE (Hessen, Germany). M.E. has received funding from the European Union Seventh Framework Programme (FP7/2007–2013) under grant agreement n° NMP-LA-2012-280432.; esteem2jra2; esteem2jra3 Approved Most recent IF: 2.878; 2015 IF: 2.325  
  Call Number c:irua:129199 c:irua:129199 Serial 3942  
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Author Teunissen, J.L.; Braeckevelt, T.; Skvortsova, I.; Guo, J.; Pradhan, B.; Debroye, E.; Roeffaers, M.B.J.; Hofkens, J.; Van Aert, S.; Bals, S.; Rogge, S.M.J.; Van Speybroeck, V. pdf  url
doi  openurl
  Title Additivity of Atomic Strain Fields as a Tool to Strain-Engineering Phase-Stabilized CsPbI3Perovskites Type A1 Journal Article
  Year 2023 Publication (up) The Journal of Physical Chemistry C Abbreviated Journal J. Phys. Chem. C  
  Volume 127 Issue 48 Pages 23400-23411  
  Keywords A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ;  
  Abstract CsPbI3 is a promising perovskite material for photovoltaic applications in its photoactive perovskite or black phase. However, the material degrades to a photovoltaically inactive or yellow phase at room temperature. Various mitigation strategies are currently being developed to increase the lifetime of the black phase, many of which rely on inducing strains in the material that hinder the black-to-yellow phase transition. Physical insight into how these strategies exactly induce strain as well as knowledge of the spatial extent over which these strains impact the material is crucial to optimize these approaches but is still lacking. Herein, we combine machine learning potential-based molecular dynamics simulations with our in silico strain engineering approach to accurately quantify strained large-scale atomic structures on a nanosecond time scale. To this end, we first model the strain fields introduced by atomic substitutions as they form the most elementary strain sources. We demonstrate that the magnitude of the induced strain fields decays exponentially with the distance from the strain source, following a decay rate that is largely independent of the specific substitution. Second, we show that the total strain field induced by multiple strain sources can be predicted to an excellent approximation by summing the strain fields of each individual source. Finally, through a case study, we illustrate how this additive character allows us to explain how complex strain fields, induced by spatially extended strain sources, can be predicted by adequately combining the strain fields caused by local strain sources. Hence, the strain additivity proposed here can be adopted to further our insight into the complex strain behavior in perovskites and to design strain from the atomic level onward to enhance their sought-after phase stability.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 001116862000001 Publication Date 2023-12-07  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1932-7447 ISBN Additional Links UA library record; WoS full record  
  Impact Factor 3.7 Times cited Open Access OpenAccess  
  Notes This work was supported by iBOF-21-085 PERsist (Special Research Fund of Ghent University, KU Leuven Research Fund, and the Research Fund of the University of Antwerp). S.M.J.R., T.B., and B.P. acknowledge financial support from the Research Foundation-Flanders (FWO) through two postdoctoral fellow- ships [grant nos. 12T3522N (S.M.J.R.) and 1275521N (B.P.)] and an SB-FWO fellowship [grant no. 1SC1319 (T.B.)]. E.D., M.B.J.R., and J.H. acknowledge financial support from the Research Foundation-Flanders (FWO, grant nos. G.0B39.15, G.0B49.15, G098319N, S002019N, S004322N, and ZW15_09- GOH6316). J.H. acknowledges support from the Flemish government through long-term structural funding Methusalem (CASAS2, Meth/15/04) and the MPI as an MPI fellow. S.V.A. and S.B. acknowledge financial support from the Research Foundation-Flanders (FWO, grant no. G0A7723N). S.M.J.R. and V.V.S. acknowledge funding from the Research Board of Ghent University (BOF). The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center), funded by the Research Foundation- Flanders (FWO) and the Flemish Government�department EWI.; KU Leuven, iBOF-21-085 PERsist ; Universiteit Antwerpen, iBOF-21-085 PERsist ; Universiteit Gent, iBOF-21-085 PERsist ; Vlaamse regering, CASAS2, Meth/15/04 ; Fonds Wetenschappelijk Onderzoek, G.0B39.15 G098319N G.0B49.15 1SC1319 12T3522N ZW15 09-GOH6316 G0A7723N 1275521N S004322N S002019N ; Approved Most recent IF: 3.7; 2023 IF: 4.536  
  Call Number EMAT @ emat @c:irua:202124 Serial 8985  
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Author Delfino, C.L.; Hao, Y.; Martin, C.; Minoia, A.; Gopi, E.; Mali, K.S.; Van der Auweraer, M.; Geerts, Y.H.; Van Aert, S.; Lazzaroni, R.; De Feyter, S. pdf  url
doi  openurl
  Title Conformation-Dependent Monolayer and Bilayer Structures of an Alkylated TTF Derivative Revealed using STM and Molecular Modeling Type A1 Journal Article
  Year 2023 Publication (up) The Journal of Physical Chemistry C Abbreviated Journal J. Phys. Chem. C  
  Volume 127 Issue 47 Pages 23023-23033  
  Keywords A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ;  
  Abstract In this study, the multi-layer self-assembled molecular network formation of an alkylated tetrathiafulvalene compound is studied at the liquid-solid interface between 1-phenyloctane and graphite. A combined theoretical/experimental approach associating force-field and quantum-chemical calculations with scanning tunnelling microscopy is used to determine the two-dimensional self-assembly beyond the monolayer, but also to further the understanding of the molecular adsorption conformation and its impact on the molecular packing within the assemblies at the monolayer and bilayer level.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 001111637100001 Publication Date 2023-11-30  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1932-7447 ISBN Additional Links UA library record; WoS full record  
  Impact Factor 3.7 Times cited Open Access OpenAccess  
  Notes Financial support from the Research Foundation-Flanders (FWO G081518N, G0A3220N) and KU Leuven–Internal Funds (C14/19/079) is acknowledged. This work was in part supported by FWO and F. R. S.-FNRS under the Excellence of Science EOS program (project 30489208 and 40007495). C.M. acknowledges the financial support: Grants PID2021-128761OA-C22 and CNS2022-136052 funded by MCIN/AEI/10.13039/501100011033 by the “European Union” and SBPLY/21/180501/000127 funded by JCCM and by the EU through “Fondo Europeo de Desarollo Regional” (FEDER). Research in Mons is also supported by the Belgian National Fund for Scientific Research (FRS-FNRS) within the Consortium des Équipements de Calcul Intensif – CÉCI, under Grant 2.5020.11, and by the Walloon Region (ZENOBE Tier-1 supercomputer, under grant 1117545). Approved Most recent IF: 3.7; 2023 IF: 4.536  
  Call Number EMAT @ emat @c:irua:201671 Serial 8974  
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Author Wang, A.; Turner, S.; Van Aert, S.; van Dyck, D. pdf  url
doi  openurl
  Title An alternative approach to determine attainable resolution directly from HREM images Type A1 Journal article
  Year 2013 Publication (up) Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume 133 Issue Pages 50-61  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab  
  Abstract The concept of resolution in high-resolution electron microscopy (HREM) is the power to resolve neighboring atoms. Since the resolution is related to the width of the point spread function of the microscope, it could in principle be determined from the image of a point object. However, in electron microscopy there are no ideal point objects. The smallest object is an individual atom. If the width of an atom is much smaller than the resolution of the microscope, this atom can still be considered as a point object. As the resolution of the microscope enters the sub-Å regime, information about the microscope is strongly entangled with the information about the atoms in HREM images. Therefore, we need to find an alternative method to determine the resolution in an object-independent way. In this work we propose to use the image wave of a crystalline object in zone axis orientation. Under this condition, the atoms of a column act as small lenses so that the electron beam channels through the atom column periodically. Because of this focusing, the image wave of the column can be much more peaked than the constituting atoms and can thus be a much more sensitive probe to measure the resolution. Our approach is to use the peakiness of the image wave of the atom column to determine the resolution. We will show that the resolution can be directly linked to the total curvature of the atom column wave. Moreover, we can then directly obtain the resolution of the microscope given that the contribution from the object is known, which is related to the bounding energy of the atom. The method is applied on an experimental CaTiO3 image wave.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000324471800007 Publication Date 2013-05-23  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record  
  Impact Factor 2.843 Times cited Open Access  
  Notes FWO; Hercules; Esteem2; esteem2_jra2 Approved Most recent IF: 2.843; 2013 IF: 2.745  
  Call Number UA @ lucian @ c:irua:109919 Serial 90  
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Author de Backer, A.; Martinez, G.T.; Rosenauer, A.; Van Aert, S. pdf  url
doi  openurl
  Title Atom counting in HAADF STEM using a statistical model-based approach : methodology, possibilities, and inherent limitations Type A1 Journal article
  Year 2013 Publication (up) Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume 134 Issue Pages 23-33  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract In the present paper, a statistical model-based method to count the number of atoms of monotype crystalline nanostructures from high resolution high-angle annular dark-field (HAADF) scanning transmission electron microscopy (STEM) images is discussed in detail together with a thorough study on the possibilities and inherent limitations. In order to count the number of atoms, it is assumed that the total scattered intensity scales with the number of atoms per atom column. These intensities are quantitatively determined using model-based statistical parameter estimation theory. The distribution describing the probability that intensity values are generated by atomic columns containing a specific number of atoms is inferred on the basis of the experimental scattered intensities. Finally, the number of atoms per atom column is quantified using this estimated probability distribution. The number of atom columns available in the observed STEM image, the number of components in the estimated probability distribution, the width of the components of the probability distribution, and the typical shape of a criterion to assess the number of components in the probability distribution directly affect the accuracy and precision with which the number of atoms in a particular atom column can be estimated. It is shown that single atom sensitivity is feasible taking the latter aspects into consideration.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000324474900005 Publication Date 2013-05-17  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.843 Times cited 48 Open Access  
  Notes FWO; Esteem2; FP 2007-2013; esteem2_jra2 Approved Most recent IF: 2.843; 2013 IF: 2.745  
  Call Number UA @ lucian @ c:irua:109916 Serial 162  
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Author Egoavil, R.; Gauquelin, N.; Martinez, G.T.; Van Aert, S.; Van Tendeloo, G.; Verbeeck, J. pdf  url
doi  openurl
  Title Atomic resolution mapping of phonon excitations in STEM-EELS experiments Type A1 Journal article
  Year 2014 Publication (up) Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume 147 Issue Pages 1-7  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Atomically resolved electron energy-loss spectroscopy experiments are commonplace in modern aberration-corrected transmission electron microscopes. Energy resolution has also been increasing steadily with the continuous improvement of electron monochromators. Electronic excitations however are known to be delocalized due to the long range interaction of the charged accelerated electrons with the electrons in a sample. This has made several scientists question the value of combined high spatial and energy resolution for mapping interband transitions and possibly phonon excitation in crystals. In this paper we demonstrate experimentally that atomic resolution information is indeed available at very low energy losses around 100 meV expressed as a modulation of the broadening of the zero loss peak. Careful data analysis allows us to get a glimpse of what are likely phonon excitations with both an energy loss and gain part. These experiments confirm recent theoretical predictions on the strong localization of phonon excitations as opposed to electronic excitations and show that a combination of atomic resolution and recent developments in increased energy resolution will offer great benefit for mapping phonon modes in real space.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000343157400001 Publication Date 2014-05-29  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.843 Times cited 22 Open Access  
  Notes 246102 IFOX; 278510 VORTEX; 246791 COUNTATOMS; Hercules; 312483 ESTEEM2; esteem2jra3 ECASJO; Approved Most recent IF: 2.843; 2014 IF: 2.436  
  Call Number UA @ lucian @ c:irua:118332UA @ admin @ c:irua:118332 Serial 177  
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Author van den Broek, W.; Rosenauer, A.; Goris, B.; Martinez, G.T.; Bals, S.; Van Aert, S.; van Dyck, D. pdf  doi
openurl 
  Title Correction of non-linear thickness effects in HAADF STEM electron tomography Type A1 Journal article
  Year 2012 Publication (up) Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume 116 Issue Pages 8-12  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab  
  Abstract In materials science, high angle annular dark field scanning transmission electron microscopy is often used for tomography at the nanometer scale. In this work, it is shown that a thickness dependent, non-linear damping of the recorded intensities occurs. This results in an underestimated intensity in the interior of reconstructions of homogeneous particles, which is known as the cupping artifact. In this paper, this non-linear effect is demonstrated in experimental images taken under common conditions and is reproduced with a numerical simulation. Furthermore, an analytical derivation shows that these non-linearities can be inverted if the imaging is done quantitatively, thus preventing cupping in the reconstruction.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000304473700002 Publication Date 2012-03-09  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.843 Times cited 67 Open Access  
  Notes Fwo Approved Most recent IF: 2.843; 2012 IF: 2.470  
  Call Number UA @ lucian @ c:irua:96558 Serial 518  
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Author Wang, A.; Chen, F.R.; Van Aert, S.; van Dyck, D. pdf  doi
openurl 
  Title Direct structure inversion from exit waves: part 1: theory and simulations Type A1 Journal article
  Year 2010 Publication (up) Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume 110 Issue 5 Pages 527-534  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab  
  Abstract In order to interpret the amplitude and phase of the exit wave in terms of mass and position of the atoms, one has to invert the dynamic scattering of the electrons in the object so as to obtain a starting structure which can then be used as a seed for further quantitative structure refinement. This is especially challenging in case of a zone axis condition when the interaction of the electrons with the atom column is very strong. Based on the channelling theory we will show that the channelling map not only yields a circle on the Argand plot but also a circular defocus curve for every column. The former gives the number of atoms in each column, while the latter provides the defocus value for each column, which reveals the surface roughness at the exit plane with single atom sensitivity.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000279065700019 Publication Date 2009-12-12  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.843 Times cited 25 Open Access  
  Notes Fwo Approved Most recent IF: 2.843; 2010 IF: 2.063  
  Call Number UA @ lucian @ c:irua:83691 Serial 723  
Permanent link to this record
 

 
Author Wang, A.; Chen, F.R.; Van Aert, S.; van Dyck, D. pdf  doi
openurl 
  Title Direct structure inversion from exit waves : part 2 : a practical example Type A1 Journal article
  Year 2012 Publication (up) Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume 116 Issue Pages 77-85  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab  
  Abstract This paper is the second part of a two-part paper on direct structure inversion from exit waves. In the first part, a method has been proposed to quantitatively determine structure parameters with atomic resolution such as atom column positions, surface profile and the number of atoms in the atom columns. In this part, the theory will be demonstrated by means of a Au[110] exit wave reconstructed from a set of focal-series images. The procedures to analyze the experimentally reconstructed exit wave in terms of quantitative structure information are described in detail.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000304473700011 Publication Date 2012-03-28  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.843 Times cited 8 Open Access  
  Notes Fwo Approved Most recent IF: 2.843; 2012 IF: 2.470  
  Call Number UA @ lucian @ c:irua:96660 Serial 724  
Permanent link to this record
 

 
Author den Dekker, A.J.; Van Aert, S.; van Dyck, D.; van den Bos, A.; Geuens, P. doi  openurl
  Title Does a monochromator improve the precision in quantitative HRTEM? Type A1 Journal article
  Year 2001 Publication (up) Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume 89 Issue Pages 275-290  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000172667000004 Publication Date 2002-07-25  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.843 Times cited 22 Open Access  
  Notes Approved Most recent IF: 2.843; 2001 IF: 1.890  
  Call Number UA @ lucian @ c:irua:47518 Serial 746  
Permanent link to this record
 

 
Author de Backer, A.; Martinez, G.T.; MacArthur, K.E.; Jones, L.; Béché, A.; Nellist, P.D.; Van Aert, S. pdf  url
doi  openurl
  Title Dose limited reliability of quantitative annular dark field scanning transmission electron microscopy for nano-particle atom-counting Type A1 Journal article
  Year 2015 Publication (up) Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume 151 Issue 151 Pages 56-61  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Quantitative annular dark field scanning transmission electron microscopy (ADF STEM) has become a powerful technique to characterise nano-particles on an atomic scale. Because of their limited size and beam sensitivity, the atomic structure of such particles may become extremely challenging to determine. Therefore keeping the incoming electron dose to a minimum is important. However, this may reduce the reliability of quantitative ADF STEM which will here be demonstrated for nano-particle atom-counting. Based on experimental ADF STEM images of a real industrial catalyst, we discuss the limits for counting the number of atoms in a projected atomic column with single atom sensitivity. We diagnose these limits by combining a thorough statistical method and detailed image simulations.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000351237800008 Publication Date 2014-12-03  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.843 Times cited 29 Open Access  
  Notes 312483 Esteem2; 278510 Vortex; Fwo G039311; G006410; G037413; esteem2ta; ECASJO; Approved Most recent IF: 2.843; 2015 IF: 2.436  
  Call Number c:irua:123927 c:irua:123927 Serial 753  
Permanent link to this record
 

 
Author Van Aert, S.; Chang, L.Y.; Bals, S.; Kirkland, A.I.; Van Tendeloo, G. pdf  doi
openurl 
  Title Effect of amorphous layers on the interpretation of restored exit waves Type A1 Journal article
  Year 2009 Publication (up) Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume 109 Issue 3 Pages 237-246  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The effects of amorphous layers on the quality of exit wave restorations have been investigated. Two independently developed software implementations for exit wave restoration have been used to simulated focal series of images of SrTiO3 with amorphous carbon layers incorporated. The restored exit waves have been compared both qualitatively and quantitatively. We have shown that amorphous layers have a strong impact on the quantitative measurements of atomic column positions, however, the error in the position measurements is still in the picometer range.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000264280200005 Publication Date 2008-11-15  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.843 Times cited 10 Open Access  
  Notes Fwo; Esteem 026019 Approved Most recent IF: 2.843; 2009 IF: 2.067  
  Call Number UA @ lucian @ c:irua:76421 Serial 796  
Permanent link to this record
 

 
Author Croitoru, M.D.; van Dyck, D.; Van Aert, S.; Bals, S.; Verbeeck, J. pdf  doi
openurl 
  Title An efficient way of including thermal diffuse scattering in simulation of scanning transmission electron microscopic images Type A1 Journal article
  Year 2006 Publication (up) Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume 106 Issue 10 Pages 933-940  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT); Vision lab  
  Abstract We propose an improved image simulation procedure for atomic-resolution annular dark-field scanning transmission electron microscopy (STEM) based on the multislice formulation, which takes thermal diffuse scattering fully into account. The improvement with regard to the classical frozen phonon approach is realized by separating the lattice configuration statistics from the dynamical scattering so as to avoid repetitive calculations. As an example, the influence of phonon scattering on the image contrast is calculated and investigated. STEM image simulation of crystals can be applied with reasonable computing times to problems involving a large number of atoms and thick or large supercells.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000240397200006 Publication Date 2006-05-10  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.843 Times cited 18 Open Access  
  Notes Fwo; Fwo-V Approved Most recent IF: 2.843; 2006 IF: 1.706  
  Call Number UA @ lucian @ c:irua:87604UA @ admin @ c:irua:87604 Serial 876  
Permanent link to this record
 

 
Author Van Aert, S.; Geuens, P.; van Dyck, D.; Kisielowski, C.; Jinschek, J.R. doi  openurl
  Title Electron channelling based crystallography Type A1 Journal article
  Year 2007 Publication (up) Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume 107 Issue 6/7 Pages 551-558  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000245341300015 Publication Date 2006-12-13  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.843 Times cited 32 Open Access  
  Notes Approved Most recent IF: 2.843; 2007 IF: 1.996  
  Call Number UA @ lucian @ c:irua:64286 Serial 913  
Permanent link to this record
 

 
Author den Dekker, A.J.; Gonnissen, J.; de Backer, A.; Sijbers, J.; Van Aert, S. pdf  doi
openurl 
  Title Estimation of unknown structure parameters from high-resolution (S)TEM images : what are the limits? Type A1 Journal article
  Year 2013 Publication (up) Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume 134 Issue Pages 34-43  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab  
  Abstract Statistical parameter estimation theory is proposed as a quantitative method to measure unknown structure parameters from electron microscopy images. Images are then purely considered as data planes from which structure parameters have to be determined as accurately and precisely as possible using a parametric statistical model of the observations. For this purpose, an efficient algorithm is proposed for the estimation of atomic column positions and intensities from high angle annular dark field (HAADF) scanning transmission electron microscopy (STEM) images. Furthermore, the so-called CramérRao lower bound (CRLB) is reviewed to determine the limits to the precision with which continuous parameters such as atomic column positions and intensities can be estimated. Since this lower bound can only be derived for continuous parameters, alternative measures using the principles of detection theory are introduced for problems concerning the estimation of discrete parameters such as atomic numbers. An experimental case study is presented to show the practical use of these measures for the optimization of the experiment design if the purpose is to decide between the presence of specific atom types using STEM images.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000324474900006 Publication Date 2013-06-01  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.843 Times cited 31 Open Access  
  Notes FWO; FP 2007-2013; Esteem2; esteem2_jra2 Approved Most recent IF: 2.843; 2013 IF: 2.745  
  Call Number UA @ lucian @ c:irua:109240 Serial 1083  
Permanent link to this record
 

 
Author de Backer, A.; Van Aert, S.; van Dyck, D. pdf  url
doi  openurl
  Title High precision measurements of atom column positions using model-based exit wave reconstruction Type A1 Journal article
  Year 2011 Publication (up) Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume 111 Issue 9/10 Pages 1475-1482  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab  
  Abstract In this paper, it has been investigated how to measure atom column positions as accurately and precisely as possible using a focal series of images. In theory, it is expected that the precision would considerably improve using a maximum likelihood estimator based on the full series of focal images. As such, the theoretical lower bound on the variances of the unknown atom column positions can be attained. However, this approach is numerically demanding. Therefore, maximum likelihood estimation has been compared with the results obtained by fitting a model to a reconstructed exit wave rather than to the full series of focal images. Hence, a real space model-based exit wave reconstruction technique based on the channelling theory is introduced. Simulations show that the reconstructed complex exit wave contains the same amount of information concerning the atom column positions as the full series of focal images. Only for thin samples, which act as weak phase objects, this information can be retrieved from the phase of the reconstructed complex exit wave.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000300461200004 Publication Date 2011-07-28  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.843 Times cited 8 Open Access  
  Notes Fwo Approved Most recent IF: 2.843; 2011 IF: 2.471  
  Call Number UA @ lucian @ c:irua:91879 Serial 1438  
Permanent link to this record
 

 
Author Dunin-Borkowski, R.E.; Lichte, H.; Tillmann, K.; Van Aert, S.; Van Tendeloo, G. pdf  url
doi  openurl
  Title Introduction to a special issue in honour of W. Owen Saxton, David J. Smith and Dirk Van Dyck on the occasion of their 65th birthdays Type Editorial
  Year 2013 Publication (up) Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume 134 Issue Pages 1-1  
  Keywords Editorial; Electron microscopy for materials research (EMAT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Elsevier science bv Place of Publication Amsterdam Editor  
  Language Wos 000324474900001 Publication Date 2013-07-24  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.843 Times cited 1 Open Access  
  Notes Approved Most recent IF: 2.843; 2013 IF: 2.745  
  Call Number UA @ lucian @ c:irua:109917 Serial 1721  
Permanent link to this record
 

 
Author van Dyck, D.; Van Aert, S.; den Dekker, A.J.; van den Bos, A. doi  openurl
  Title Is atomic resolution transmission electron microscopy able to resolve and refine amorphous structures? Type A1 Journal article
  Year 2003 Publication (up) Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume 98 Issue Pages 27-42  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000186831500003 Publication Date 2003-04-25  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.843 Times cited 26 Open Access  
  Notes Approved Most recent IF: 2.843; 2003 IF: 1.665  
  Call Number UA @ lucian @ c:irua:47516 Serial 1749  
Permanent link to this record
 

 
Author Van Aert, S.; Chen, J.H.; van Dyck, D. pdf  doi
openurl 
  Title Linear versus non-linear structural information limit in high-resolution transmission electron microscopy Type A1 Journal article
  Year 2010 Publication (up) Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume 110 Issue 11 Pages 1404-1410  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab  
  Abstract A widely used performance criterion in high-resolution transmission electron microscopy (HRTEM) is the information limit. It corresponds to the inverse of the maximum spatial object frequency that is linearly transmitted with sufficient intensity from the exit plane of the object to the image plane and is limited due to partial temporal coherence. In practice, the information limit is often measured from a diffractogram or from Young's fringes assuming a weak phase object scattering beyond the inverse of the information limit. However, for an aberration corrected electron microscope, with an information limit in the sub-angstrom range, weak phase objects are no longer applicable since they do not scatter sufficiently in this range. Therefore, one relies on more strongly scattering objects such as crystals of heavy atoms observed along a low index zone axis. In that case, dynamical scattering becomes important such that the non-linear and linear interaction may be equally important. The non-linear interaction may then set the experimental cut-off frequency observed in a diffractogram. The goal of this paper is to quantify both the linear and the non-linear information transfer in terms of closed form analytical expressions. Whereas the cut-off frequency set by the linear transfer can be directly related with the attainable resolution, information from the non-linear transfer can only be extracted using quantitative, model-based methods. In contrast to the historic definition of the information limit depending on microscope parameters only, the expressions derived in this paper explicitly incorporate their dependence on the structure parameters as well. In order to emphasize this dependence and to distinguish from the usual information limit, the expressions derived for the inverse cut-off frequencies will be referred to as the linear and non-linear structural information limit. The present findings confirm the well-known result that partial temporal coherence has different effects on the transfer of the linear and non-linear terms, such that the non-linear imaging contributions are damped less than the linear imaging contributions at high spatial frequencies. This will be important when coherent aberrations such as spherical aberration and defocus are reduced.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000282562100008 Publication Date 2010-07-15  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.843 Times cited 6 Open Access  
  Notes Fwo Approved Most recent IF: 2.843; 2010 IF: 2.063  
  Call Number UA @ lucian @ c:irua:83689 Serial 1821  
Permanent link to this record
 

 
Author den Dekker, A.J.; Van Aert, S.; van den Bos, A.; van Dyck, D. pdf  doi
openurl 
  Title Maximum likelihood estimation of structure parameters from high resolution electron microscopy images: part 1: a theoretical framework Type A1 Journal article
  Year 2005 Publication (up) Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume 104 Issue 2 Pages 83-106  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000230526400001 Publication Date 2005-04-09  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.843 Times cited 70 Open Access  
  Notes Approved Most recent IF: 2.843; 2005 IF: 2.490  
  Call Number UA @ lucian @ c:irua:57229 Serial 1959  
Permanent link to this record
 

 
Author Van Aert, S.; den Dekker, A.J.; van den Bos, A.; van Dyck, D.; Chen, J.H. pdf  doi
openurl 
  Title Maximum likelihood estimation of structure parameters from high resolution electron microscopy images : part 2 : a practical example Type A1 Journal article
  Year 2005 Publication (up) Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume 104 Issue 2 Pages 107-125  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000230526400002 Publication Date 2005-04-08  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.843 Times cited 37 Open Access  
  Notes Approved Most recent IF: 2.843; 2005 IF: 2.490  
  Call Number UA @ lucian @ c:irua:57131 Serial 1960  
Permanent link to this record
 

 
Author Van den Broek, W.; Rosenauer, A.; Van Aert, S.; Sijbers, J.; van Dyck, D. pdf  url
doi  openurl
  Title A memory efficient method for fully three-dimensional object reconstruction with HAADF STEM Type A1 Journal article
  Year 2014 Publication (up) Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume 141 Issue Pages 22-31  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab  
  Abstract The conventional approach to object reconstruction through electron tomography is to reduce the three-dimensional problem to a series of independent two-dimensional slice-by-slice reconstructions. However, at atomic resolution the image of a single atom extends over many such slices and incorporating this image as prior knowledge in tomography or depth sectioning therefore requires a fully three-dimensional treatment. Unfortunately, the size of the three-dimensional projection operator scales highly unfavorably with object size and readily exceeds the available computer memory. In this paper, it is shown that for incoherent image formation the memory requirement can be reduced to the fundamental lower limit of the object size, both for tomography and depth sectioning. Furthermore, it is shown through multislice calculations that high angle annular dark field scanning transmission electron microscopy can be sufficiently incoherent for the reconstruction of single element nanocrystals, but that dynamical diffraction effects can cause classification problems if more than one element is present. (C) 2014 Elsevier B.V. All rights reserved.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000335766600004 Publication Date 2014-03-22  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.843 Times cited 6 Open Access  
  Notes ResearchFoundationFlanders(FWO;G.0393.11; G.0064.10;andG.0374.13); European Union Seventh Frame- workProgramme [FP7/2007-2013]under Grant agreement no. 312483 (ESTEEM2).; esteem2jra2; esteem2jra4 Approved Most recent IF: 2.843; 2014 IF: 2.436  
  Call Number UA @ lucian @ c:irua:117650 Serial 1992  
Permanent link to this record
 

 
Author Wang, A.; Chen, F.R.; Van Aert, S.; van Dyck, D. pdf  doi
openurl 
  Title A method to determine the local surface profile from reconstructed exit waves Type A1 Journal article
  Year 2011 Publication (up) Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume 111 Issue 8 Pages 1352-1359  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab  
  Abstract Reconstructed exit waves are useful to quantify unknown structure parameters such as the position and composition of the atom columns at atomic scale. Existing techniques provide a complex wave in a flat plane which is close to the plane where the electrons leave the atom columns. However, due to local deviation in the flatness of the exit surface, there will be an offset between the plane of reconstruction and the actual exit of a specific atom column. Using the channelling theory, it has been shown that this defocus offset can in principle be determined atom column-by-atom column. As such, the surface roughness could be quantified at atomic scale. However, the outcome strongly depends on the initial plane of reconstruction especially in a crystalline structure. If this plane is further away from the true exit, the waves of the atom columns become delocalized and interfere mutually which strongly complicates the interpretation of the exit wave in terms of the local structure. In this paper, we will study the delocalization with defocus using the channelling theory in a more systematic way.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000300461100049 Publication Date 2011-05-03  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.843 Times cited 3 Open Access  
  Notes Fwo Approved Most recent IF: 2.843; 2011 IF: 2.471  
  Call Number UA @ lucian @ c:irua:88941 Serial 2017  
Permanent link to this record
 

 
Author van den Broek, W.; Van Aert, S.; van Dyck, D. doi  openurl
  Title A model based atomic resolution tomographic algorithm Type A1 Journal article
  Year 2009 Publication (up) Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume 109 Issue 12 Pages 1485-1490  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab  
  Abstract Tomography with high angular annular dark field scanning transmission electron microscopy at atomic resolution can be greatly improved if one is able to take advantage of prior knowledge. In this paper we present a reconstruction technique that explicitly takes into account the microscope parameters and the atomic nature of the projected object. This results in a more accurate estimate of the atomic positions and in a good resistance to noise. The reconstruction is a maximum likelihood estimator of the object. Moreover, the limits to the precision have been explored, allowing for a prediction of the amount of expected noise in the reconstruction for a certain experimental setup. We believe that the proposed reconstruction technique can be generalized to other tomographic experiments.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000271840200010 Publication Date 2009-08-28  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.843 Times cited 17 Open Access  
  Notes Approved Most recent IF: 2.843; 2009 IF: 2.067  
  Call Number UA @ lucian @ c:irua:78588 Serial 2097  
Permanent link to this record
 

 
Author Verbeeck, J.; Van Aert, S. pdf  doi
openurl 
  Title Model based quantification of EELS spectra Type A1 Journal article
  Year 2004 Publication (up) Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume 101 Issue 2/4 Pages 207-224  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Recent advances in model based quantification of electron energy loss spectra (EELS) are reported. The maximum likelihood method for the estimation of physical parameters describing an EELS spectrum, the validation of the model used in this estimation procedure, and the computation of the attainable precision, that is, the theoretical lower bound on the variance of these estimates, are discussed. Experimental examples on An and GaAs samples show the power of the maximum likelihood method and show that the theoretical prediction of the attainable precision can be closely approached even for spectra with overlapping edges where conventional EELS quantification fails. To provide end-users with a low threshold alternative to conventional quantification, a user friendly program was developed which is freely available under a GNU public license. (C) 2004 Elsevier B.V. All rights reserved.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000224046100016 Publication Date 2004-07-23  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.843 Times cited 147 Open Access  
  Notes Fwo; Iuap P5/01 Approved Most recent IF: 2.843; 2004 IF: 2.215  
  Call Number UA @ lucian @ c:irua:57130UA @ admin @ c:irua:57130 Serial 2101  
Permanent link to this record
 

 
Author Verbeeck, J.; Van Aert, S.; Bertoni, G. pdf  doi
openurl 
  Title Model-based quantification of EELS spectra: including the fine structure Type A1 Journal article
  Year 2006 Publication (up) Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume 106 Issue 11-12 Pages 976-980  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract An extension to model-based electron energy loss spectroscopy (EELS) quantification is reported to improve the possibility of modelling fine structure changes in electron energy loss spectra. An equalisation function is used in the energy loss near edge structure (ELNES) region to model the differences between a single atom differential cross section and the cross section for an atom in a crystal. The equalisation function can be shown to approximate the relative density of unoccupied states for the given excitation edge. On a set of 200 experimental h-BN spectra, this technique leads to statistically acceptable models resulting into unbiased estimates of relative concentrations and making the estimated precisions come very close to the Cramer-Rao lower bound (CRLB). The method greatly expands the useability of model-based EELS quantification to spectra with pronounced fine structure. Another benefit of this model is that one also gets an estimate of the unoccupied density of states for a given excitation edge, without having to do background removal and deconvolution, making the outcome intrinsically more reliable and less noisy. (c) 2006 Elsevier B.V. All rights reserved.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000241592900004 Publication Date 2006-07-04  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.843 Times cited 38 Open Access  
  Notes Goa; Fwo Iap-V Approved Most recent IF: 2.843; 2006 IF: 1.706  
  Call Number UA @ lucian @ c:irua:61379UA @ admin @ c:irua:61379 Serial 2102  
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