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Author | Roelandts, T.; Batenburg, K.J.; Biermans, E.; Kübel, C.; Bals, S.; Sijbers, J. | ||||
Title | Accurate segmentation of dense nanoparticles by partially discrete electron tomography | Type | A1 Journal article | ||
Year | 2012 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
Volume | 114 | Issue | Pages | 96-105 | |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab | ||||
Abstract | Accurate segmentation of nanoparticles within various matrix materials is a difficult problem in electron tomography. Due to artifacts related to image series acquisition and reconstruction, global thresholding of reconstructions computed by established algorithms, such as weighted backprojection or SIRT, may result in unreliable and subjective segmentations. In this paper, we introduce the Partially Discrete Algebraic Reconstruction Technique (PDART) for computing accurate segmentations of dense nanoparticles of constant composition. The particles are segmented directly by the reconstruction algorithm, while the surrounding regions are reconstructed using continuously varying gray levels. As no properties are assumed for the other compositions of the sample, the technique can be applied to any sample where dense nanoparticles must be segmented, regardless of the surrounding compositions. For both experimental and simulated data, it is shown that PDART yields significantly more accurate segmentations than those obtained by optimal global thresholding of the SIRT reconstruction. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Amsterdam | Editor | ||
Language | Wos | 000301954300011 | Publication Date | 2012-01-06 | |
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 ![]() |
34 | Open Access | |
Notes | Fwo | Approved | Most recent IF: 2.843; 2012 IF: 2.470 | ||
Call Number | UA @ lucian @ c:irua:97710 | Serial | 52 | ||
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Author | Gauquelin, N.; van den Bos, K.H.W.; Béché, A.; Krause, F.F.; Lobato, I.; Lazar, S.; Rosenauer, A.; Van Aert, S.; Verbeeck, J. | ||||
Title | Determining oxygen relaxations at an interface: A comparative study between transmission electron microscopy techniques | Type | A1 Journal article | ||
Year | 2017 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
Volume | 181 | Issue | 181 | Pages | 178-190 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Nowadays, aberration corrected transmission electron microscopy (TEM) is a popular method to characterise nanomaterials at the atomic scale. Here, atomically resolved images of nanomaterials are acquired, where the contrast depends on the illumination, imaging and detector conditions of the microscope. Visualization of light elements is possible when using low angle annular dark field (LAADF) STEM, annular bright field (ABF) STEM, integrated differential phase contrast (iDPC) STEM, negative spherical aberration imaging (NCSI) and imaging STEM (ISTEM). In this work, images of a NdGaO3-La0.67Sr0.33MnO3 (NGO-LSMO) interface are quantitatively evaluated by using statistical parameter estimation theory. For imaging light elements, all techniques are providing reliable results, while the techniques based on interference contrast, NCSI and ISTEM, are less robust in terms of accuracy for extracting heavy column locations. In term of precision, sample drift and scan distortions mainly limits the STEM based techniques as compared to NCSI. Post processing techniques can, however, partially compensate for this. In order to provide an outlook to the future, simulated images of NGO, in which the unavoidable presence of Poisson noise is taken into account, are used to determine the ultimate precision. In this future counting noise limited scenario, NCSI and ISTEM imaging will provide more precise values as compared to the other techniques, which can be related to the mechanisms behind the image recording. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000411170800022 | Publication Date | 2017-06-03 | |
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 ![]() |
34 | Open Access | OpenAccess |
Notes | The authors acknowledge financial support from Flanders (FWO, Belgium) through project fundings (G.0044.13N, G.0374.13N, G.0368.15N, G.0369.15N), and by a Ph.D. grant to K.H.W.v.d.B. The Qu-Ant-EM microscope used for this study was partly funded by the Hercules fund from the Flemish Government. A.B. and N.G. acknowledge the EUROTAPES project (FP7-NMP.2011.2.2-1 Grant no.280432) which partly funded this study. N.G., A.B. and J.V. acknowledge funding from the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant 278510 VORTEX. The research leading to these results has received funding from the Deutsche Forschungsgemeinschaft under Contract No. RO 2057/4-2 and the European Union Seventh Framework Programme under Grant Agreement 312483 – ESTEEM2. We thank Prof. G. Koster from the University of Twente for kindly providing us with the LSMO-NGO test sample. | Approved | Most recent IF: 2.843 | ||
Call Number | EMAT @ emat @ c:irua:144435UA @ admin @ c:irua:144435 | Serial | 4620 | ||
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Author | Van Aert, S.; Geuens, P.; van Dyck, D.; Kisielowski, C.; Jinschek, J.R. | ||||
Title | Electron channelling based crystallography | Type | A1 Journal article | ||
Year | 2007 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
Volume | 107 | Issue | 6/7 | Pages | 551-558 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab | ||||
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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 | ||
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Author | Lobato, I.; Van Dyck, D. | ||||
Title | MULTEM : a new multislice program to perform accurate and fast electron diffraction and imaging simulations using graphics processing units with CUDA | Type | A1 Journal article | ||
Year | 2015 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
Volume | 156 | Issue | 156 | Pages | 9-17 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab | ||||
Abstract | The main features and the GPU implementation of the MULTEM program are presented and described. This new program performs accurate and fast multislice simulations by including higher order expansion of the multislice solution of the high energy Schrodinger equation, the correct subslicing of the three-dimensional potential and top-bottom surfaces. The program implements different kinds of simulation for CTEM, STEM, ED, PED, CBED, ADF-TEM and ABF-HC with proper treatment of the spatial and temporal incoherences. The multislice approach described here treats the specimen as amorphous material which allows a straightforward implementation of the frozen phonon approximation. The generalized transmission function for each slice is calculated when is needed and then discarded. This allows us to perform large simulations that can include millions of atoms and keep the computer memory requirements to a reasonable level. (C) 2015 Elsevier B.V. All rights reserved. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Amsterdam | Editor | ||
Language | Wos | 000361001800003 | Publication Date | 2015-04-28 | |
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 ![]() |
32 | Open Access | |
Notes | Approved | Most recent IF: 2.843; 2015 IF: 2.436 | |||
Call Number | UA @ lucian @ c:irua:127848 | Serial | 4209 | ||
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Author | den Dekker, A.J.; Gonnissen, J.; de Backer, A.; Sijbers, J.; Van Aert, S. | ||||
Title | Estimation of unknown structure parameters from high-resolution (S)TEM images : what are the limits? | Type | A1 Journal article | ||
Year | 2013 | Publication | 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. | ||||
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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 | ||
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Author | Béché, A.; Rouvière, J.L.; Barnes, J.P.; Cooper, D. | ||||
Title | Dark field electron holography for strain measurement | Type | A1 Journal article | ||
Year | 2011 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
Volume | 111 | Issue | 3 | Pages | 227-238 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Dark field electron holography is a new TEM-based technique for measuring strain with nanometer scale resolution. Here we present the procedure to align a transmission electron microscope and obtain dark field holograms as well as the theoretical background necessary to reconstruct strain maps from holograms. A series of experimental parameters such as biprism voltage, sample thickness, exposure time, tilt angle and choice of diffracted beam are then investigated on a silicon-germanium layer epitaxially embedded in a silicon matrix in order to obtain optimal dark field holograms over a large field of view with good spatial resolution and strain sensitivity. | ||||
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Publisher | Place of Publication | Amsterdam | Editor | ||
Language | Wos | 000288638200007 | Publication Date | 2010-12-01 | |
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 | Approved | Most recent IF: 2.843; 2011 IF: 2.471 | |||
Call Number | UA @ lucian @ c:irua:136368 | Serial | 4496 | ||
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Author | Jannis, D.; Hofer, C.; Gao, C.; Xie, X.; Béché, A.; Pennycook, Tj.; Verbeeck, J. | ||||
Title | Event driven 4D STEM acquisition with a Timepix3 detector: Microsecond dwell time and faster scans for high precision and low dose applications | Type | A1 Journal article | ||
Year | 2022 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
Volume | 233 | Issue | Pages | 113423 | |
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
Abstract | Four dimensional scanning transmission electron microscopy (4D STEM) records the scattering of electrons in a material in great detail. The benefits offered by 4D STEM are substantial, with the wealth of data it provides facilitating for instance high precision, high electron dose efficiency phase imaging via centre of mass or ptychography based analysis. However the requirement for a 2D image of the scattering to be recorded at each probe position has long placed a severe bottleneck on the speed at which 4D STEM can be performed. Recent advances in camera technology have greatly reduced this bottleneck, with the detection efficiency of direct electron detectors being especially well suited to the technique. However even the fastest frame driven pixelated detectors still significantly limit the scan speed which can be used in 4D STEM, making the resulting data susceptible to drift and hampering its use for low dose beam sensitive applications. Here we report the development of the use of an event driven Timepix3 direct electron camera that allows us to overcome this bottleneck and achieve 4D STEM dwell times down to 100 ns; orders of magnitude faster than what has been possible with frame based readout. We characterize the detector for different acceleration voltages and show that the method is especially well suited for low dose imaging and promises rich datasets without compromising dwell time when compared to conventional STEM imaging. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000734396800003 | Publication Date | 2021-11-13 | |
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 | 2.2 | Times cited ![]() |
31 | Open Access | OpenAccess |
Notes | This project has received funding from the Euro- pean Union’s Horizon 2020 Research Infrastructure – Integrating Activities for Advanced Communities under grant agreement No 823717 – ESTEEM3. J.V. and A.B. acknowledge funding from FWO project G093417N (‘Compressed sensing enabling low dose imaging in transmission electron microscopy’). J.V. and D.J. ac- knowledge funding from FWO project G042920N ‘Co- incident event detection for advanced spectroscopy in transmission electron microscopy’. We acknowledge funding under the European Union’s Horizon 2020 re- search and innovation programme (J.V. and D.J un- der grant agreement No 101017720, FET-Proactive EBEAM, and C.H., C.G., X.X. and T.J.P. from the Eu- ropean Research Council (ERC) Grant agreement No. 802123-HDEM).; esteem3JRA; esteem3reported | Approved | Most recent IF: 2.2 | ||
Call Number | EMAT @ emat @c:irua:183948 | Serial | 6828 | ||
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Author | Béché, A.; Juchtmans, R.; Verbeeck, J. | ||||
Title | Efficient creation of electron vortex beams for high resolution STEM imaging | Type | A1 Journal article | ||
Year | 2017 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
Volume | 178 | Issue | 178 | Pages | 12-19 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | The recent discovery of electron vortex beams carrying quantised angular momentum in the TEM has led to an active field of research, exploring a variety of potential applications including the possibility of mapping magnetic states at the atomic scale. A prerequisite for this is the availability of atomic sized electron vortex beams at high beam current and mode purity. In this paper we present recent progress showing that by making use of the Aharonov-Bohm effect near the tip of a long single domain ferromagnetic Nickel needle, a very efficient aperture for the production of electron vortex beams can be realised. The aperture transmits more than 99% of all electrons and provides a vortex mode purity of up to 92%. Placing this aperture in the condenser plane of a state of the art Cs corrected microscope allows us to demonstrate atomic resolution HAADF STEM images with spatial resolution better than 1 Angstrom, in agreement with theoretical expectations and only slightly inferior to the performance of a non-vortex probe on the same instrument. | ||||
Address | EMAT, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium | ||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | English | Wos | 000403862900003 | Publication Date | 2016-05-10 |
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 ![]() |
30 | Open Access | OpenAccess |
Notes | A.B. and J.V. acknowledge funding from the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant No. 278510 VORTEX. J.V. acknowledges funding from FWO project G.0044.13N ('Charge ordering').; ECASJO_; | Approved | Most recent IF: 2.843 | ||
Call Number | c:irua:134085 c:irua:134085UA @ admin @ c:irua:134085 | Serial | 4094 | ||
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Author | de Backer, A.; Martinez, G.T.; MacArthur, K.E.; Jones, L.; Béché, A.; Nellist, P.D.; Van Aert, S. | ||||
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 | 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. | ||||
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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 | ||
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Author | Verbeeck, J.; Béché, A.; van den Broek, W. | ||||
Title | A holographic method to measure the source size broadening in STEM | Type | A1 Journal article | ||
Year | 2012 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
Volume | 120 | Issue | Pages | 35-40 | |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Source size broadening is an important resolution limiting effect in modern STEM experiments. Here, we propose an alternative method to measure the source size broadening making use of a holographic biprism to create interference patterns in an empty Ronchigram. This allows us to measure the exact shape of the source size broadening with a much better sampling than previously possible. We find that the shape of the demagnified source deviates considerably from a Gaussian profile that is often assumed. We fit the profile with a linear combination of a Gaussian and a bivariate Cauchy distribution showing that even though the full width at half maximum is similar to previously reported measurements, the tails of the profile are considerable wider. This is of fundamental importance for quantitative comparison of STEM simulations with experiments as these tails make the image contrast dependent on the interatomic distance, an effect that cannot be reproduced by a single Gaussian profile of fixed width alone. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Amsterdam | Editor | ||
Language | Wos | 000308082600005 | Publication Date | 2012-06-01 | |
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 ![]() |
29 | Open Access | |
Notes | This work was supported by funding from the European Research Council under the 7th Framework Program (FP7), ERC Grant no. 246791 COUNTATOMS and ERC Starting Grant 278510 VORTEX. The Qu-Ant-EM microscope was partly funded by the Hercules fund from the Flemish Government. W. Van den Broek acknowledges funding from the Condor project, a project under the supervision of the Embedded Systems Institute (ESI) and FEI. This project is partially supported by the Dutch Ministry of Economic Affairs under the BSIK program. ECASJO_; | Approved | Most recent IF: 2.843; 2012 IF: 2.470 | ||
Call Number | UA @ lucian @ c:irua:100466UA @ admin @ c:irua:100466 | Serial | 1483 | ||
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Author | Potapov, P.L.; Schryvers, D. | ||||
Title | Measuring the absolute position of EELS ionisation edges in a TEM | Type | A1 Journal article | ||
Year | 2004 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
Volume | 99 | Issue | Pages | 73-85 | |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
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Publisher | Place of Publication | Amsterdam | Editor | ||
Language | Wos | 000220804700005 | Publication Date | 2003-08-12 | |
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 ![]() |
29 | Open Access | |
Notes | Approved | Most recent IF: 2.843; 2004 IF: 2.215 | |||
Call Number | UA @ lucian @ c:irua:48781 | Serial | 1970 | ||
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Author | Potapov, P.; Lichte, H.; Verbeeck, J.; van Dyck, D. | ||||
Title | Experiments on inelastic electron holography | Type | A1 Journal article | ||
Year | 2006 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
Volume | 106 | Issue | 11-12 | Pages | 1012-1018 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab | ||||
Abstract | Using the combination of an electron biprism and an energy filter, the coherence distribution in an inelastically scattered wave-field is measured. It is found that the degree of coherence decreases rapidly with increasing distance between two superimposed points in the object, and with increasing energy-loss. In a Si sample, coherence of plasmon scattering increases in vacuum with the distance from the edge of the sample. (c) 2006 Published by Elsevier B.V. | ||||
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Publisher | Place of Publication | Amsterdam | Editor | ||
Language | Wos | 000241592900009 | Publication Date | 2006-07-07 | |
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 ![]() |
28 | Open Access | |
Notes | Approved | Most recent IF: 2.843; 2006 IF: 1.706 | |||
Call Number | UA @ lucian @ c:irua:61380UA @ admin @ c:irua:61380 | Serial | 1147 | ||
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Author | Verbeeck, J.; Hébert; Rubino, S.; Novák, P.; Rusz, J.; Houdellier, F.; Gatel, C.; Schattschneider, P. | ||||
Title | Optimal aperture sizes and positions for EMCD experiments | Type | A1 Journal article | ||
Year | 2008 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
Volume | 108 | Issue | 9 | Pages | 865-872 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | The signal-to-noise ratio (SNR) in energy-loss magnetic chiral dichroism (EMCD)the equivalent of X-ray magnetic circular dichroism (XMCD) in the electron microscopeis optimized with respect to the detector shape, size and position. We show that an important increase in SNR over previous experiments can be obtained when taking much larger detector sizes. We determine the ideal shape of the detector but also show that round apertures are a good compromise if placed in their optimal position. We develop the theory for a simple analytical description of the EMCD experiment and then apply it to dynamical multibeam Bloch wave calculations and to an experimental data set. In all cases it is shown that a significant and welcome improvement of the SNR is possible. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Amsterdam | Editor | ||
Language | Wos | 000258747600009 | Publication Date | 2008-03-07 | |
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 ![]() |
27 | Open Access | |
Notes | This work was supported by the European Commission under contract no. 508971 CHIRALTEM. J.V. and F.H. thank the financial support from the European Union under the Framework 6 program under a contract for an Integrated Infrastructure Initiative. Reference 026019 ESTEEM. Thanks to J.P. Morniroli for making the Fe sample available. | Approved | Most recent IF: 2.843; 2008 IF: 2.629 | ||
Call Number | UA @ lucian @ c:irua:76492UA @ admin @ c:irua:76492 | Serial | 2480 | ||
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Author | Martinez, G.T.; Jones, L.; de Backer, A.; Béché, A.; Verbeeck, J.; Van Aert, S.; Nellist, P.D. | ||||
Title | Quantitative STEM normalisation : the importance of the electron flux | Type | A1 Journal article | ||
Year | 2015 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
Volume | 159 | Issue | 159 | Pages | 46-58 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Annular dark-field (ADF) scanning transmission electron microscopy (STEM) has become widely used in quantitative studies based on the opportunity to directly compare experimental and simulated images. This comparison merely requires the experimental data to be normalised and expressed in units of fractional beam-current. However, inhomogeneities in the response of electron detectors can complicate this normalisation. The quantification procedure becomes both experiment and instrument specific, requiring new simulations for the particular response of each instrument's detector, and for every camera-length used. This not only impedes the comparison between different instruments and research groups, but can also be computationally very time consuming. Furthermore, not all image simulation methods allow for the inclusion of an inhomogeneous detector response. In this work, we propose an alternative method for normalising experimental data in order to compare these with simulations that consider a homogeneous detector response. To achieve this, we determine the electron flux distribution reaching the detector by means of a camera-length series or a so-called atomic column cross-section averaged convergent beam electron diffraction (XSACBED) pattern. The result is then used to determine the relative weighting of the detector response. Here we show that the results obtained by this new electron flux weighted (EFW) method are comparable to the currently used method, while considerably simplifying the needed simulation libraries. The proposed method also allows one to obtain a metric that describes the quality of the detector response in comparison with the ideal detector response. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Amsterdam | Editor | ||
Language | Wos | 000366220000006 | Publication Date | 2015-08-01 | |
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 ![]() |
27 | Open Access | |
Notes | 246791 Countatoms; 278510 Vortex; 312483 Esteem2; Fwo G036815; G036915; G037413; G004413; esteem2ta ECASJO; | Approved | Most recent IF: 2.843; 2015 IF: 2.436 | ||
Call Number | c:irua:127293 c:irua:127293UA @ admin @ c:irua:127293 | Serial | 2762 | ||
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Author | van Dyck, D.; Van Aert, S.; den Dekker, A.J.; van den Bos, A. | ||||
Title | Is atomic resolution transmission electron microscopy able to resolve and refine amorphous structures? | Type | A1 Journal article | ||
Year | 2003 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
Volume | 98 | Issue | Pages | 27-42 | |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab | ||||
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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 | Heidari Mezerji, H.; van den Broek, W.; Bals, S. | ||||
Title | A practical method to determine the effective resolution in incoherent experimental electron tomography | Type | A1 Journal article | ||
Year | 2011 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
Volume | 111 | Issue | 5 | Pages | 330-336 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab | ||||
Abstract | It is not straightforward to determine resolution for a 3D reconstruction when performing an electron tomography experiment. Different contributions such as missing wedge and misalignment add up and often influence the final resolution in an anisotropic manner. The conventional resolution measures can not be used for all of the reconstruction techniques, especially for iterative techniques which are more commonly used for electron tomography in materials science. Here we define a quantitative resolution measure that determines the resolution in three orthogonal directions of the reconstruction. As an application we use this measure to determine the optimum number of simultaneous iterative reconstruction technique (SIRT) iterations to reconstruct the gold nanoparticles, based on a high angle annular dark field STEM (HAADF-STEM) tilt series. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Amsterdam | Editor | ||
Language | Wos | 000289396900005 | Publication Date | 2011-01-24 | |
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 ![]() |
26 | Open Access | |
Notes | Esteem 026019; Fwo | Approved | Most recent IF: 2.843; 2011 IF: 2.471 | ||
Call Number | UA @ lucian @ c:irua:87606 | Serial | 2688 | ||
Permanent link to this record | |||||
Author | Zhong, Z.; Goris, B.; Schoenmakers, R.; Bals, S.; Batenburg, K.J. | ||||
Title | A bimodal tomographic reconstruction technique combining EDS-STEM and HAADF-STEM | Type | A1 Journal article | ||
Year | 2017 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
Volume | 174 | Issue | 174 | Pages | 35-45 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | A three-dimensional (3D) chemical characterization of nanomaterials can be obtained using tomography based on high angle annular dark field (HAADF) scanning transmission electron microscopy (STEM) or energy dispersive X-ray spectroscopy (EDS) STEM. These two complementary techniques have both advantages and disadvantages. The Z-contrast images have good image quality but lack robustness in the compositional analysis, while the elemental maps give more element-specific information, but at a low signal-to-noise ratio and a longer exposure time. Our aim is to combine these two types of complementary information in one single tomographic reconstruction process. Therefore, an imaging model is proposed combining both HAADF-STEM and EDS-STEM. Based on this model, the elemental distributions can be reconstructed using both types of information simultaneously during the reconstruction process. The performance of the new technique is evaluated using simulated data and real experimental data. The results demonstrate that combining two imaging modalities leads to tomographic reconstructions with suppressed noise and enhanced contrast. |
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Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000403342200005 | Publication Date | 2016-12-11 | |
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 | OpenAccess |
Notes | This research is supported by the Dutch Technology Foundation STW (http://www.stw.nl/), which is part of the Netherlands Organization for Scientific Research (NWO), and which is partly funded by the Ministry of Economic Affairs, Agriculture and Innovation under project number 13314. It is also supported by the Flemish research foundation (FWO Vlaanderen) by project funding (G038116N) and a postdoctoral research grant to B.G. Funding from the European Research Council (Starting Grant No. COLOURATOMS 335078) is acknowledged by S.B. The authors would like to thank Dr. Bernd Rieger and Dr. Richard Aveyard for useful discussions, and Prof. Dr. Luis M. Liz-Marzan for providing the investigated samples. We also acknowledge COST Action MP1207 for networking support. (ROMEO:green; preprint:; postprint:can ; pdfversion:cannot); saraecas; ECAS_Sara; | Approved | Most recent IF: 2.843 | ||
Call Number | EMAT @ emat @ c:irua:141719UA @ admin @ c:irua:141719 | Serial | 4484 | ||
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Author | Wang, A.; Chen, F.R.; Van Aert, S.; van Dyck, D. | ||||
Title | Direct structure inversion from exit waves: part 1: theory and simulations | Type | A1 Journal article | ||
Year | 2010 | Publication | 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 | Bladt, E.; Pelt, D.M.; Bals, S.; Batenburg, K.J. | ||||
Title | Electron tomography based on highly limited data using a neural network reconstruction technique | Type | A1 Journal article | ||
Year | 2015 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
Volume | 158 | Issue | 158 | Pages | 81-88 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab | ||||
Abstract | Gold nanoparticles are studied extensively due to their unique optical and catalytical properties. Their exact shape determines the properties and thereby the possible applications. Electron tomography is therefore often used to examine the three-dimensional (3D) shape of nanoparticles. However, since the acquisition of the experimental tilt series and the 3D reconstructions are very time consuming, it is difficult to obtain statistical results concerning the 3D shape of nanoparticles. Here, we propose a new approach for electron tomography that is based on artificial neural networks. The use of a new reconstruction approach enables us to reduce the number of projection images with a factor of 5 or more. The decrease in acquisition time of the tilt series and use of an efficient reconstruction algorithm allows us to examine a large amount of nanoparticles in order to retrieve statistical results concerning the 3D shape. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Amsterdam | Editor | ||
Language | Wos | 000361574800011 | Publication Date | 2015-07-10 | |
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 ![]() |
25 | Open Access | OpenAccess |
Notes | 335078 COLOURATOM; FWO; COST Action MP1207; 312483 ESTEEM2; esteem2jra4; ECASSara; (ROMEO:green; preprint:; postprint:can ; pdfversion:cannot); | Approved | Most recent IF: 2.843; 2015 IF: 2.436 | ||
Call Number | c:irua:126675 c:irua:126675 | Serial | 988 | ||
Permanent link to this record | |||||
Author | Rosenauer, A.; Schowalter, M.; Titantah, J.T.; Lamoen, D. | ||||
Title | An emission-potential multislice approximation to simulate thermal diffuse scattering in high-resolution transmission electron microscopy | Type | A1 Journal article | ||
Year | 2008 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
Volume | 108 | Issue | 12 | Pages | 1504-1513 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Thermal diffuse scattered electrons significantly contribute to high-resolution transmission electron microscopy images. Their intensity adds to the background and is peaked at positions of atomic columns. In this paper we suggest an approximation to simulate intensity of thermal diffuse scattered electrons in plane-wave illumination transmission electron microscopy using an emission-potential multislice algorithm which is computationally less intensive than the frozen lattice approximation or the mutual intensity approach. Intensity patterns are computed for Au and InSb for different crystal orientations. These results are compared with intensities from the frozen lattice approximation based on uncorrelated vibration of atoms as well as with the frozen phonon approximation for Au. The frozen phonon method uses a detailed phonon model based on force constants we computed by a density functional theory approach. The comparison shows that our suggested emission-potential method is in close agreement with both the frozen lattice and the frozen phonon approximations. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Amsterdam | Editor | ||
Language | Wos | 000260808300002 | Publication Date | 2008-04-21 | |
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 | Approved | Most recent IF: 2.843; 2008 IF: 2.629 | |||
Call Number | UA @ lucian @ c:irua:72919 | Serial | 1033 | ||
Permanent link to this record | |||||
Author | Müller-Caspary, K.; Krause, F.F.; Winkler, F.; Béché, A.; Verbeeck, J.; Van Aert, S.; Rosenauer, A. | ||||
Title | Comparison of first moment STEM with conventional differential phase contrast and the dependence on electron dose | Type | A1 Journal article | ||
Year | 2019 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
Volume | 203 | Issue | 203 | Pages | 95-104 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | This study addresses the comparison of scanning transmission electron microscopy (STEM) measurements of momentum transfers using the first moment approach and the established method that uses segmented annular detectors. Using an ultrafast pixelated detector to acquire four-dimensional, momentum-resolved STEM signals, both the first moment calculation and the calculation of the differential phase contrast (DPC) signals are done for the same experimental data. In particular, we investigate the ability to correct the segment-based signal to yield a suitable approximation of the first moment for cases beyond the weak phase object approximation. It is found that the measurement of momentum transfers using segmented detectors can approach the first moment measurement as close as 0.13 h/nm in terms of a root mean square (rms) difference in 10 nm thick SrTiO3 for a detector with 16 segments. This amounts to 35% of the rms of the momentum transfers. In addition, we present a statistical analysis of the precision of first moment STEM as a function of dose. For typical experimental settings with recent hardware such as a Medipix3 Merlin camera attached to a probe-corrected STEM, we find that the precision of the measurement of momentum transfers stagnates above certain doses. This means that other instabilities such as specimen drift or scan noise have to be taken into account seriously for measurements that target, e.g., the detection of bonding effects in the charge density. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000465021000013 | Publication Date | 2018-12-30 | |
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 | OpenAccess |
Notes | ; The direct electron detector (Medipix3 Merlin) was funded by the Hercules fund from the Flemish Government. K. Muller-Caspary acknowledges funding from the Initiative and Network Fund of the Helmholtz Association within the framework of the Helmholtz Young Investigator Group moreSTEM (VH-NG-1317) at Forschungszentrum Julich, Germany. F. F. Krause acknowledges funding from the Central Research Development Fund of the University of Bremen, Germany. 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). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) and the Research Fund of the University of Antwerp. ; | Approved | Most recent IF: 2.843 | ||
Call Number | UA @ admin @ c:irua:160213 | Serial | 5242 | ||
Permanent link to this record | |||||
Author | Hadermann, J.; Abakumov, A.M.; Tsirlin, A.A.; Filonenko, V.P.; Gonnissen, J.; Tan, H.; Verbeeck, J.; Gemmi, M.; Antipov, E.V.; Rosner, H. | ||||
Title | Direct space structure solution from precession electron diffraction data: resolving heavy and light scatterers in Pb13Mn9O25 | Type | A1 Journal article | ||
Year | 2010 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
Volume | 110 | Issue | 7 | Pages | 881-890 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | The crystal structure of a novel compound Pb13Mn9O25 has been determined through a direct space structure solution with a Monte-Carlo-based global optimization using precession electron diffraction data (a=14.177(3) Å, c=3.9320(7) Å, SG P4/m, RF=0.239) and compositional information obtained from energy dispersive X-ray analysis and electron energy loss spectroscopy. This allowed to obtain a reliable structural model even despite the simultaneous presence of both heavy (Pb) and light (O) scattering elements and to validate the accuracy of the electron diffraction-based structure refinement. This provides an important benchmark for further studies of complex structural problems with electron diffraction techniques. Pb13Mn9O25 has an anion- and cation-deficient perovskite-based structure with the A-positions filled by the Pb atoms and 9/13 of the B positions filled by the Mn atoms in an ordered manner. MnO6 octahedra and MnO5 tetragonal pyramids form a network by sharing common corners. Tunnels are formed in the network due to an ordered arrangement of vacancies at the B-sublattice. These tunnels provide sufficient space for localization of the lone 6s2 electron pairs of the Pb2+ cations, suggested as the driving force for the structural difference between Pb13Mn9O25 and the manganites of alkali-earth elements with similar compositions. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Amsterdam | Editor | ||
Language | Wos | 000280050900023 | Publication Date | 2010-04-01 | |
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 ![]() |
24 | Open Access | |
Notes | Fwo; Bof; Esteem | Approved | Most recent IF: 2.843; 2010 IF: 2.063 | ||
Call Number | UA @ lucian @ c:irua:84085UA @ admin @ c:irua:84085 | Serial | 721 | ||
Permanent link to this record | |||||
Author | de Backer, A.; De wael, A.; Gonnissen, J.; Van Aert, S. | ||||
Title | Optimal experimental design for nano-particle atom-counting from high-resolution STEM images | Type | A1 Journal article | ||
Year | 2015 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
Volume | 151 | Issue | 151 | Pages | 46-55 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | In the present paper, the principles of detection theory are used to quantify the probability of error for atom-counting from high resolution scanning transmission electron microscopy (HR STEM) 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 for the probability of error. We show that for very thin objects LAADF is optimal and that for thicker objects the optimal inner detector angle increases. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Amsterdam | Editor | ||
Language | Wos | 000351237800007 | Publication Date | 2014-11-11 | |
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 ![]() |
24 | Open Access | |
Notes | 312483 Esteem2; Fwo G039311; G037413; esteem2_jra2 | Approved | Most recent IF: 2.843; 2015 IF: 2.436 | ||
Call Number | c:irua:123926 c:irua:123926 | Serial | 2481 | ||
Permanent link to this record | |||||
Author | Schattschneider, P.; Stöger-Pollach, M.; Löffler, S.; Steiger-Thirsfeld, A.; Hell, J.; Verbeeck, J. | ||||
Title | Sub-nanometer free electrons with topological charge | Type | A1 Journal article | ||
Year | 2012 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
Volume | 115 | Issue | Pages | 21-25 | |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | The holographic mask technique is used to create freely moving electrons with quantized angular momentum. With electron optical elements they can be focused to vortices with diameters below the nanometer range. The understanding of these vortex beams is important for many applications. Here, we produce electron vortex beams and compare them to a theory of electrons with topological charge. The experimental results show excellent agreement with simulations. As an immediate application, fundamental experimental parameters like spherical aberration and partial coherence are determined. (C) 2012 Elsevier B.V. All rights reserved. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Amsterdam | Editor | ||
Language | Wos | 000302962400004 | Publication Date | 2012-01-30 | |
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 ![]() |
24 | Open Access | |
Notes | vortex ECASJO_; | Approved | Most recent IF: 2.843; 2012 IF: 2.470 | ||
Call Number | UA @ lucian @ c:irua:98279 | Serial | 3344 | ||
Permanent link to this record | |||||
Author | Egoavil, R.; Gauquelin, N.; Martinez, G.T.; Van Aert, S.; Van Tendeloo, G.; Verbeeck, J. | ||||
Title | Atomic resolution mapping of phonon excitations in STEM-EELS experiments | Type | A1 Journal article | ||
Year | 2014 | Publication | 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 | ||
Permanent link to this record | |||||
Author | den Dekker, A.J.; Van Aert, S.; van Dyck, D.; van den Bos, A.; Geuens, P. | ||||
Title | Does a monochromator improve the precision in quantitative HRTEM? | Type | A1 Journal article | ||
Year | 2001 | Publication | 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 | Zhuge, X.; Jinnai, H.; Dunin-Borkowski, R.E.; Migunov, V.; Bals, S.; Cool, P.; Bons, A.-J.; Batenburg, K.J. | ||||
Title | Automated discrete electron tomography – Towards routine high-fidelity reconstruction of nanomaterials | Type | A1 Journal article | ||
Year | 2017 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
Volume | 175 | Issue | 175 | Pages | 87-96 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA) | ||||
Abstract | Electron tomography is an essential imaging technique for the investigation of morphology and 3D structure of nanomaterials. This method, however, suffers from well-known missing wedge artifacts due to a restricted tilt range, which limits the objectiveness, repeatability and efficiency of quantitative structural analysis. Discrete tomography represents one of the promising reconstruction techniques for materials science, potentially capable of delivering higher fidelity reconstructions by exploiting the prior knowledge of the limited number of material compositions in a specimen. However, the application of discrete tomography to practical datasets remains a difficult task due to the underlying challenging mathematical problem. In practice, it is often hard to obtain consistent reconstructions from experimental datasets. In addition, numerous parameters need to be tuned manually, which can lead to bias and non-repeatability. In this paper, we present the application of a new iterative reconstruction technique, named TVR-DART, for discrete electron tomography. The technique is capable of consistently delivering reconstructions with significantly reduced missing wedge artifacts for a variety of challenging data and imaging conditions, and can automatically estimate its key parameters. We describe the principles of the technique and apply it to datasets from three different types of samples acquired under diverse imaging modes. By further reducing the available tilt range and number of projections, we show that the proposed technique can still produce consistent reconstructions with minimized missing wedge artifacts. This new development promises to provide the electron microscopy community with an easy-to-use and robust tool for high-fidelity 3D characterization of nanomaterials. |
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Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000403342500008 | Publication Date | 2017-01-24 | |
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 ![]() |
22 | Open Access | OpenAccess |
Notes | This work has been supported in part by the Stichting voor de Technische Wetenschappen (STW) through a personal grant (Veni,13610), and was in part by ExxonMobil Chemical Europe Inc. The authors further acknowledge financial support from the University of Antwerp through BOF GOA funding. S.B. acknowledges financial support from the European Research Council (ERC Starting Grant #335078-COLOURATOMS). R.D.B. is grateful for funding from the European Research Council under the European Union's Seventh Framework Programme (FP7/2007–2013)/ ERC grant agreement number 320832. Thomas Altantzis is gratefully acknowledged for acquiring the Anatase nanosheets dataset. (ROMEO:green; preprint:; postprint:can ; pdfversion:cannot); saraecas; ECAS_Sara; | Approved | Most recent IF: 2.843 | ||
Call Number | EMAT @ emat @ c:irua:141218UA @ admin @ c:irua:141218 | Serial | 4485 | ||
Permanent link to this record | |||||
Author | Goris, B.; Bals, S.; van den Broek, W.; Verbeeck, J.; Van Tendeloo, G. | ||||
Title | Exploring different inelastic projection mechanisms for electron tomography | Type | A1 Journal article | ||
Year | 2011 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
Volume | 111 | Issue | 8 | Pages | 1262-1267 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab | ||||
Abstract | Several different projection mechanisms that all make use of inelastically scattered electrons are used for electron tomography. The advantages and the disadvantages of these methods are compared to HAADFSTEM tomography, which is considered as the standard electron tomography technique in materials science. The different inelastic setups used are energy filtered transmission electron microscopy (EFTEM), thickness mapping based on the log-ratio method and bulk plasmon mapping. We present a comparison that can be used to select the best inelastic signal for tomography, depending on different parameters such as the beam stability and nature of the sample. The appropriate signal will obviously also depend on the exact information which is requested. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Amsterdam | Editor | ||
Language | Wos | 000300461100039 | Publication Date | 2011-03-07 | |
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 ![]() |
21 | Open Access | |
Notes | Fwo; Iap; Esteem 026019 | Approved | Most recent IF: 2.843; 2011 IF: 2.471 | ||
Call Number | UA @ lucian @ c:irua:91260UA @ admin @ c:irua:91260 | Serial | 1151 | ||
Permanent link to this record | |||||
Author | Ke, X.; Bals, S.; Romo Negreira, A.; Hantschel, T.; Bender, H.; Van Tendeloo, G. | ||||
Title | TEM sample preparation by FIB for carbon nanotube interconnects | Type | A1 Journal article | ||
Year | 2009 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
Volume | 109 | Issue | 11 | Pages | 1353-1359 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | A powerful method to study carbon nanotubes (CNTs) grown in patterned substrates for potential interconnects applications is transmission electron microscopy (TEM). However, high-quality TEM samples are necessary for such a study. Here, TEM specimen preparation by focused ion beam (FIB) has been used to obtain lamellae of patterned samples containing CNTs grown inside contact holes. A dual-cap Pt protection layer and an extensive 5 kV cleaning procedure are applied in order to preserve the CNTs and avoid deterioration during milling. TEM results show that the inner shell structure of the carbon nanotubes has been preserved, which proves that focused ion beam is a useful technique to prepare TEM samples of CNT interconnects. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Amsterdam | Editor | ||
Language | Wos | 000270765800006 | Publication Date | 2009-07-11 | |
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 ![]() |
21 | Open Access | |
Notes | Esteem 026019; Iap | Approved | Most recent IF: 2.843; 2009 IF: 2.067 | ||
Call Number | UA @ lucian @ c:irua:79074 | Serial | 3485 | ||
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Author | De Meulenaere, P.; Van Tendeloo, G.; van Landuyt, J.; van Dyck, D. | ||||
Title | On the interpretation of HREM images of partially ordered alloys | Type | A1 Journal article | ||
Year | 1995 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
Volume | 60 | Issue | 2 | Pages | 265-282 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab | ||||
Abstract | The ordering for 11/20 alloys has been studied by high-resolution electron microscopy (HREM). The distribution of the intensity maxima in the HREM image have been statistically examined, which provides a profound basis for the image interpretation. Processing of the HREM images allows ''dark-field'' images to be obtained, exhibiting a two-dimensional distribution of those columns which contain the most information in order to interpret the short-range order correlations. Pair correlations and higher cluster correlations between projected columns can be visualised, providing unique information about the ordering as retrieved from an experimental result without any other assumption. The method has been applied to Au4Cr and to Au4Mn to interpret the quenched short-range order state and the transition to long-range order. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Amsterdam | Editor | ||
Language | Wos | A1995TZ14700008 | 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 | 2.436 | Times cited ![]() |
20 | Open Access | |
Notes | Approved | no | |||
Call Number | UA @ lucian @ c:irua:13014 | Serial | 2438 | ||
Permanent link to this record |