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Author van den Broek, W.; Van Aert, S.; van Dyck, D.
Title (down) A model based atomic resolution tomographic algorithm Type A1 Journal article
Year 2009 Publication 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
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Author Wang, A.; Chen, F.R.; Van Aert, S.; van Dyck, D.
Title (down) A method to determine the local surface profile from reconstructed exit waves Type A1 Journal article
Year 2011 Publication 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
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Author Van den Broek, W.; Rosenauer, A.; Van Aert, S.; Sijbers, J.; van Dyck, D.
Title (down) A memory efficient method for fully three-dimensional object reconstruction with HAADF STEM Type A1 Journal article
Year 2014 Publication 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
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Author De Backer, A.; Bals, S.; Van Aert, S.
Title (down) A decade of atom-counting in STEM: From the first results toward reliable 3D atomic models from a single projection Type A1 Journal article
Year 2023 Publication Ultramicroscopy Abbreviated Journal
Volume Issue Pages 113702
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Quantitative structure determination is needed in order to study and understand nanomaterials at the atomic scale. Materials characterisation resulting in precise structural information is a crucial point to understand the structure–property relation of materials. Counting the number of atoms and retrieving the 3D atomic structure of nanoparticles plays an important role here. In this paper, an overview will be given of the atom-counting methodology and its applications over the past decade. The procedure to count the number of atoms will be discussed in detail and it will be shown how the performance of the method can be further improved. Furthermore, advances toward mixed element nanostructures, 3D atomic modelling based on the atom-counting results, and quantifying the nanoparticle dynamics will be highlighted.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000953765800001 Publication Date 2023-02-10
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 2.2 Times cited 3 Open Access OpenAccess
Notes This work was supported by the European Research Council (Grant 770887 PICOMETRICS to S. Van Aert, Grant 815128 REALNANO to S. Bals, 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 EOS 30489208) and a postdoctoral grant to A. De Backer. S. Van Aert acknowledges funding from the University of Antwerp Research fund (BOF) . The authors also thank the colleagues who have contributed to this work over the years, including T. Altantzis, E. Arslan Irmak, K.J. Batenburg, E. Bladt, A. De wael, R. Erni, C. Faes, B. Goris, L. Jones, L.M. Liz-Marzán, I. Lobato, G.T. Martinez, P.D. Nellist, M.D. Rosell, A. Rosenauer, K.H.W. van den Bos, A. Varambhia, and Z. Zhang.; esteem3reported; esteem3JRA Approved Most recent IF: 2.2; 2023 IF: 2.843
Call Number EMAT @ emat @c:irua:195896 Serial 7236
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Author Lichte, H.; Dunin-Borkowski, R.; Tillmann, K.; Van Aert, S.; Van Tendeloo, G.
Title (down) 65th birthdays of W. Owen Saxton, David J. Smith and Dirk Van Dyck / PICO 2013 From multislice to big bang Type ME3 Book as editor
Year 2013 Publication Abbreviated Journal
Volume Issue Pages
Keywords ME3 Book as editor; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos Publication Date 0000-00-00
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 Most recent IF: NA
Call Number UA @ lucian @ c:irua:109918 Serial 19
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Author Milagres de Oliveira, T.; Albrecht, W.; González-Rubio, G.; Altantzis, T.; Lobato Hoyos, I.P.; Béché, A.; Van Aert, S.; Guerrero-Martínez, A.; Liz-Marzán, L.M.; Bals, S.
Title (down) 3D Characterization and Plasmon Mapping of Gold Nanorods Welded by Femtosecond Laser Irradiation Type A1 Journal article
Year 2020 Publication Acs Nano Abbreviated Journal Acs Nano
Volume 14 Issue Pages acsnano.0c02610
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT)
Abstract Ultrafast laser irradiation can induce morphological and structural changes in plasmonic nanoparticles. Gold nanorods (Au NRs), in particular, can be welded together upon irradiation with femtosecond laser pulses, leading to dimers and trimers through the formation of necks between individual nanorods. We used electron tomography to determine the 3D (atomic) structure at such necks for representative welding geometries and to characterize the induced defects. The spatial distribution of localized surface plasmon modes for different welding configurations was assessed by electron energy loss spectroscopy. Additionally, we were able to directly compare the plasmon line width of single-crystalline and welded Au NRs with single defects at the same resonance energy, thus making a direct link between the structural and plasmonic properties. In this manner, we show that the occurrence of (single) defects results in significant plasmon broadening.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000586793400016 Publication Date 2020-08-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1936-0851 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 17.1 Times cited 25 Open Access OpenAccess
Notes This project has received funding from the European Research Council under the European Union's Horizon 2020 research and innovation program (ERC Consolidator Grants #815128 – REALNANO and #770887 – PICOMETRICS). The authors gratefully acknowledge funding from the Research Foundation Flanders (FWO, Belgium) through project funding G.0381.16N and G.0267.18N. W.A. acknowledges an Individual Fellowship funded by the Marie 27 Sklodowska-Curie Actions (MSCA) in Horizon 2020 program (grant 797153, SOPMEN). G.G.-R. acknowledge receipt of FPI Fellowship from the Spanish MINECO. This work has been funded by the Spanish Ministry of Science, Innovation and Universities (MICIU) (Grants RTI2018-095844-B-I00 and MAT2017-86659-R) and the Madrid Regional Government (Grant P2018/NMT-4389). A.B. acknowledges funding from FWO project G093417N and from the European Union's Horizon 2020 research and innovation programme under grant agreement No 823717 – ESTEEM3. L.M.L.-M. acknowledges the Maria de Maeztu Units of Excellence Program from the Spanish State Research Agency (Grant No. MDM-2017-0720); Comunidad de Madrid, P2018/NMT-4389 ; Ministerio de Ciencia, Innovación y Universidades, MAT2017-86659-R RTI2018-095844-B-I00 ; Ministerio de Economía y Competitividad; H2020 Marie Sklodowska-Curie Actions, 797153 ; Fonds Wetenschappelijk Onderzoek, G.0267.18N G.0381.16N G093417N ; H2020 Research Infrastructures, 823717 ; H2020 European Research Council, 770887 815128 ; Agencia Estatal de Investigación, Ministerio de Ciencia, Innovación y Universidades, MDM-2017-0720 ; sygma Approved Most recent IF: 17.1; 2020 IF: 13.942
Call Number EMAT @ emat @c:irua:172440 Serial 6426
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Author Albrecht, W.; Arslan Irmak, E.; Altantzis, T.; Pedrazo‐Tardajos, A.; Skorikov, A.; Deng, T.‐S.; van der Hoeven, J.E.S.; van Blaaderen, A.; Van Aert, S.; Bals, S.
Title (down) 3D Atomic‐Scale Dynamics of Laser‐Light‐Induced Restructuring of Nanoparticles Unraveled by Electron Tomography Type A1 Journal article
Year 2021 Publication Advanced Materials Abbreviated Journal Adv Mater
Volume Issue Pages 2100972
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT)
Abstract Understanding light–matter interactions in nanomaterials is crucial for

optoelectronic, photonic, and plasmonic applications. Specifically, metal

nanoparticles (NPs) strongly interact with light and can undergo shape

transformations, fragmentation and ablation upon (pulsed) laser excitation.

Despite being vital for technological applications, experimental insight into

the underlying atomistic processes is still lacking due to the complexity of

such measurements. Herein, atomic resolution electron tomography is performed

on the same mesoporous-silica-coated gold nanorod, before and after

femtosecond laser irradiation, to assess the missing information. Combined

with molecular dynamics (MD) simulations based on the experimentally

determined 3D atomic-scale morphology, the complex atomistic rearrangements,

causing shape deformations and defect generation, are unraveled.

These rearrangements are simultaneously driven by surface diffusion, facet

restructuring, and strain formation, and are influenced by subtleties in the

atomic distribution at the surface.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000671662000001 Publication Date 2021-07-11
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0935-9648 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 19.791 Times cited 8 Open Access OpenAccess
Notes W.A. and E.A.I. contributed equally to this work. The authors acknowledge funding from the European Research Council under the European Union’s Horizon 2020 research and innovation program (ERC Consolidator Grants No. 815128 – REALNANO and No. 770887 – PICOMETRICS), the European Union’s Seventh Framework Programme (ERC Advanced Grant No. 291667 – HierarSACol), and the European Commission (EUSMI). W.A. acknowledges an Individual Fellowship funded by the Marie Sklodowska-Curie Actions (MSCA) in the Horizon2020 program (Grant 797153, SOPMEN). T.-S.D. acknowledges financial support from the National Science Foundation of China (NSFC, Grant No. 61905056). The authors also acknowledge financial support by the Research Foundation Flanders (FWO Grant G.0267.18N).; sygmaSB Approved Most recent IF: 19.791
Call Number EMAT @ emat @c:irua:179781 Serial 6805
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Author Arslan Irmak, E.; Liu, P.; Bals, S.; Van Aert, S.
Title (down) 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 Most recent IF: NA
Call Number EMAT @ emat @c:irua:183289 Serial 6820
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