Records |
Author |
Mueller, K.; Krause, F.F.; Béché, A.; Schowalter, M.; Galioit, V.; Loeffler, S.; Verbeeck, J.; Zweck, J.; Schattschneider, P.; Rosenauer, A. |
Title |
Atomic electric fields revealed by a quantum mechanical approach to electron picodiffraction |
Type |
A1 Journal article |
Year |
2014 |
Publication |
Nature communications |
Abbreviated Journal |
Nat Commun |
Volume |
5 |
Issue |
|
Pages |
5653 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
By focusing electrons on probes with a diameter of 50 pm, aberration-corrected scanning transmission electron microscopy (STEM) is currently crossing the border to probing subatomic details. A major challenge is the measurement of atomic electric fields using differential phase contrast (DPC) microscopy, traditionally exploiting the concept of a field- induced shift of diffraction patterns. Here we present a simplified quantum theoretical interpretation of DPC. This enables us to calculate the momentum transferred to the STEM probe from diffracted intensities recorded on a pixel array instead of conventional segmented bright- field detectors. The methodical development yielding atomic electric field, charge and electron density is performed using simulations for binary GaN as an ideal model system. We then present a detailed experimental study of SrTiO3 yielding atomic electric fields, validated by comprehensive simulations. With this interpretation and upgraded instrumentation, STEM is capable of quantifying atomic electric fields and high-contrast imaging of light atoms. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000347227700003 |
Publication Date |
2014-12-15 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
|
ISSN |
2041-1723; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
12.124 |
Times cited |
197 |
Open Access |
|
Notes |
246791 COUNTATOMS; 278510 VORTEX; Hercules; 312483 ESTEEM2; esteem2ta; ECASJO; |
Approved |
Most recent IF: 12.124; 2014 IF: 11.470 |
Call Number |
UA @ lucian @ c:irua:122835UA @ admin @ c:irua:122835 |
Serial |
166 |
Permanent link to this record |
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|
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Author |
Li, K.; Béché, A.; Song, M.; Sha, G.; Lu, X.; Zhang, K.; Du, Y.; Ringer, S.P.; Schryvers, D. |
Title |
Atomistic structure of Cu-containing \beta" precipitates in an Al-Mg-Si-Cu alloy |
Type |
A1 Journal article |
Year |
2014 |
Publication |
Scripta materialia |
Abbreviated Journal |
Scripta Mater |
Volume |
75 |
Issue |
|
Pages |
86-89 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
The beta '' precipitates in a peak-aged Al-Mg-Si-Cu alloy were measured with an average composition of 28.6Al-38.7Mg-26.5Si-5.17Cu (at.%) using atom probe tomography. High-angle annular dark-field observations revealed that Cu incompletely substitutes for the Mg-1 and Si-3 columns, preferentially for one column in each pair of Si-3. Cu-free Si columns form a parallelogram-shaped network that constitutes the basis of subsequent precipitates in the system, with a = 0.37 nm, b = 0.38 nm, gamma = 113 degrees and c = 0.405 nm. (C) 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Oxford |
Editor |
|
Language |
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Wos |
000331025200022 |
Publication Date |
2013-12-07 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
|
ISSN |
1359-6462; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.747 |
Times cited |
22 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.747; 2014 IF: 3.224 |
Call Number |
UA @ lucian @ c:irua:115749 |
Serial |
201 |
Permanent link to this record |
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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. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
000351237800008 |
Publication Date |
2014-12-03 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
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Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
|
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 |
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|
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Author |
Clark, L.; Béché, A.; Guzzinati, G.; Lubk, A.; Mazilu, M.; Van Boxem, R.; Verbeeck, J. |
Title |
Exploiting lens aberrations to create electron-vortex beams |
Type |
A1 Journal article |
Year |
2013 |
Publication |
Physical review letters |
Abbreviated Journal |
Phys Rev Lett |
Volume |
111 |
Issue |
6 |
Pages |
064801-64805 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
A model for a new electron-vortex beam production method is proposed and experimentally demonstrated. The technique calls on the controlled manipulation of the degrees of freedom of the lens aberrations to achieve a helical phase front. These degrees of freedom are accessible by using the corrector lenses of a transmission electron microscope. The vortex beam is produced through a particular alignment of these lenses into a specifically designed astigmatic state and applying an annular aperture in the condenser plane. Experimental results are found to be in good agreement with simulations. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000322921200009 |
Publication Date |
2013-08-08 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
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ISSN |
0031-9007;1079-7114; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
8.462 |
Times cited |
66 |
Open Access |
|
Notes |
Vortex; Esteem2; Countatoms; FWO; Esteem2jra3 ECASJO; |
Approved |
Most recent IF: 8.462; 2013 IF: 7.728 |
Call Number |
UA @ lucian @ c:irua:109340UA @ admin @ c:irua:109340 |
Serial |
1148 |
Permanent link to this record |
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|
|
Author |
Béché, A.; Winkler, R.; Plank, H.; Hofer, F.; Verbeeck, J. |
Title |
Focused electron beam induced deposition as a tool to create electron vortices |
Type |
A1 Journal article |
Year |
2015 |
Publication |
Micron |
Abbreviated Journal |
Micron |
Volume |
80 |
Issue |
80 |
Pages |
34-38 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Focused electron beam induced deposition (FEBID) is a microscopic technique that allows geometrically controlled material deposition with very high spatial resolution. This technique was used to create a spiral aperture capable of generating electron vortex beams in a transmission electron microscope (TEM). The vortex was then fully characterized using different TEM techniques, estimating the average orbital angular momentum to be approximately 0.8variant Planck's over 2pi per electron with almost 60% of the beam ending up in the l=1 state. |
Address |
EMAT, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium |
Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
|
Editor |
|
Language |
English |
Wos |
000366770100006 |
Publication Date |
2015-09-12 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
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ISSN |
0968-4328; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.98 |
Times cited |
21 |
Open Access |
|
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., R.W., H.P. and F.H. acknowledge financial support from the European Union under the 7th Framework Program (FP7) under a contract for an Integrated Infrastructure Initiative (Reference No. 312483 ESTEEM2). R.W and H.P also acknowledge financial support by the COST action CELINA (Nr. CM1301) and the EUROSTARS project TRIPLE-S (Nr. E!8213). The Qu-Ant-EM microscope was partly funded by the Hercules fund from the Flemish Government.; esteem2jra3 ECASJO; |
Approved |
Most recent IF: 1.98; 2015 IF: 1.988 |
Call Number |
c:irua:129203 c:irua:129203UA @ admin @ c:irua:129203 |
Serial |
3946 |
Permanent link to this record |
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|
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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. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Amsterdam |
Editor |
|
Language |
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Wos |
000308082600005 |
Publication Date |
2012-06-01 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
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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 |
Permanent link to this record |
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|
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Author |
van Huis, M.A.; Figuerola, A.; Fang, C.; Béché, A.; Zandbergen, H.W.; Manna, L. |
Title |
Letter Chemical transformation of Au-tipped CdS nanorods into AuS/Cd core/shell particles by electron beam irradiation |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Nano letters |
Abbreviated Journal |
Nano Lett |
Volume |
11 |
Issue |
11 |
Pages |
4555-4561 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
We demonstrate that electron irradiation of colloidal CdS nanorods carrying Au domains causes their evolution into AuS/Cd core/shell nanoparticles as a result of a concurrent chemical and morphological transformation. The shrinkage of the CdS nanorods and the growth of the Cd shell around the Au tips are imaged in real time, while the displacement of S atoms from the CdS nanorod to the Au domains is evidenced by high-sensitivity energy-dispersive X-ray (EDX) spectroscopy. The various nanodomains display different susceptibility to the irradiation, which results in nanoconfigurations that are very different from those obtained after thermal annealing. Such physical manipulations of colloidal nanocrystals can be exploited as a tool to access novel nanocrystal heterostructures. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Washington |
Editor |
|
Language |
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Wos |
000296674700009 |
Publication Date |
2011-10-13 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
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ISSN |
1530-6984;1530-6992; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
12.712 |
Times cited |
25 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 12.712; 2011 IF: 13.198 |
Call Number |
UA @ lucian @ c:irua:93710 |
Serial |
1814 |
Permanent link to this record |
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Author |
Béché, A.; Van Boxem, R.; Van Tendeloo, G.; Verbeeck, J. |
Title |
Magnetic monopole field exposed by electrons |
Type |
A1 Journal article |
Year |
2014 |
Publication |
Nature physics |
Abbreviated Journal |
Nat Phys |
Volume |
10 |
Issue |
1 |
Pages |
26-29 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The experimental search for magnetic monopole particles(1-3) has, so far, been in vain. Nevertheless, these elusive particles of magnetic charge have fuelled a rich field of theoretical study(4-10). Here, we created an approximation of a magnetic monopole in free space at the end of a long, nanoscopically thin magnetic needle(11). We experimentally demonstrate that the interaction of this approximate magnetic monopole field with a beam of electrons produces an electron vortex state, as theoretically predicted for a true magnetic monopole(3,11-18). This fundamental quantum mechanical scattering experiment is independent of the speed of the electrons and has consequences for all situations where electrons meet such monopole magnetic fields, as, for example, in solids. The set-up not only shows an attractive way to produce electron vortex states but also provides a unique insight into monopole fields and shows that electron vortices might well occur in unexplored solid-state physics situations. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000328940100012 |
Publication Date |
2013-11-29 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
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ISSN |
1745-2473;1745-2481; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
22.806 |
Times cited |
131 |
Open Access |
|
Notes |
Vortex; Countatoms; Fwo ECASJO_; |
Approved |
Most recent IF: 22.806; 2014 IF: 20.147 |
Call Number |
UA @ lucian @ c:irua:113740UA @ admin @ c:irua:113740 |
Serial |
1885 |
Permanent link to this record |
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Author |
Tan, H.; Egoavil, R.; Béché, A.; Martinez, G.T.; Van Aert, S.; Verbeeck, J.; Van Tendeloo, G.; Rotella, H.; Boullay, P.; Pautrat, A.; Prellier, W. |
Title |
Mapping electronic reconstruction at the metal-insulator interface in LaVO3/SrVO3 heterostructures |
Type |
A1 Journal article |
Year |
2013 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
88 |
Issue |
15 |
Pages |
155123-155126 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
A (LaVO3)6/(SrVO3)(3) superlattice is studied with a combination of sub-A resolved scanning transmission electron microscopy and monochromated electron energy-loss spectroscopy. The V oxidation state is mapped with atomic spatial resolution enabling us to investigate electronic reconstruction at the LaVO3/SrVO3 interfaces. Surprisingly, asymmetric charge distribution is found at adjacent chemically symmetric interfaces. The local structure is proposed and simulated with a double channeling calculation which agrees qualitatively with our experiment. We demonstrate that local strain asymmetry is the likely cause of the electronic asymmetry of the interfaces. The electronic reconstruction at the interfaces extends much further than the chemical composition, varying from 0.5 to 1.2 nm. This distance corresponds to the length of charge transfer previously found in the (LaVO3)./(SrVO3). metal/insulating and the (LaAlO3)./(SrTiO3). insulating/insulating interfaces. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000326087100003 |
Publication Date |
2013-10-21 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
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ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
15 |
Open Access |
|
Notes |
Hercules; 246791 COUNTATOMS; 278510 VORTEX; 246102 IFOX; 312483 ESTEEM2; FWO; GOA XANES meets ELNES; esteem2jra3 ECASJO; |
Approved |
Most recent IF: 3.836; 2013 IF: 3.664 |
Call Number |
UA @ lucian @ c:irua:112733UA @ admin @ c:irua:112733 |
Serial |
1944 |
Permanent link to this record |
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Author |
Guzzinati, G.; Clark, L.; Béché, A.; Verbeeck, J. |
Title |
Measuring the orbital angular momentum of electron beams |
Type |
A1 Journal article |
Year |
2014 |
Publication |
Physical review : A : atomic, molecular and optical physics |
Abbreviated Journal |
Phys Rev A |
Volume |
89 |
Issue |
|
Pages |
025803 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The recent demonstration of electron vortex beams has opened up the new possibility of studying orbital angular momentum (OAM) in the interaction between electron beams and matter. To this aim, methods to analyze the OAM of an electron beam are fundamentally important and a necessary next step. We demonstrate the measurement of electron beam OAM through a variety of techniques. The use of forked holographic masks, diffraction from geometric apertures, and diffraction from a knife edge and the application of an astigmatic lens are all experimentally demonstrated. The viability and limitations of each are discussed with supporting numerical simulations. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Lancaster, Pa |
Editor |
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Language |
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Wos |
000332224100014 |
Publication Date |
2014-02-13 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
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ISSN |
1050-2947;1094-1622; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.925 |
Times cited |
42 |
Open Access |
|
Notes |
Vortex; FP7; Countatoms; ESTEEM2; esteem2jra3 ECASJO; |
Approved |
Most recent IF: 2.925; 2014 IF: 2.808 |
Call Number |
UA @ lucian @ c:irua:114577UA @ admin @ c:irua:114577 |
Serial |
1972 |
Permanent link to this record |
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Author |
Verbeeck, J.; Tian, H.; Béché, A. |
Title |
A new way of producing electron vortex probes for STEM |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
113 |
Issue |
|
Pages |
83-87 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
A spiral holographic aperture is used in the condensor plane of a scanning transmission electron microscope to produce a focussed electron vortex probe carrying a topological charge of either −1, 0 or +1. The spiral aperture design has a major advantage over the previously used forked aperture in that the three beams with topological charge m=−1, 0, and 1 are not side by side in the specimen plane, but rather on top of each other, focussed at different heights. This allows us to have only one selected beam in focus on the sample while the others contribute only to a background signal. In this paper we describe the working principle as well as first experimental results demonstrating atomic resolution HAADF STEM images obtained with electron vortex probes. These results pave the way for atomic resolution magnetic information when combined with electron energy loss spectroscopy. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Amsterdam |
Editor |
|
Language |
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Wos |
000300554400002 |
Publication Date |
2011-10-31 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
|
ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.843 |
Times cited |
62 |
Open Access |
|
Notes |
J.V. wants to thank Miles Padgett for suggesting this setup and pointing to the relevant optics literature. Peter Schattschneider is acknowledged for in depth discussions on related topics. J.V acknowledges funding from the European Research Council under the 7th Framework Program (FP7), ERC Grant no. 46791-COUN-TATOMS and ERC Starting Grant no. 278510 VORTEX. The Qu-Ant-EM microscope is partially funded by the Hercules fund of the Flemish Government. ECASJO_; |
Approved |
Most recent IF: 2.843; 2012 IF: 2.470 |
Call Number |
UA @ lucian @ c:irua:93624UA @ admin @ c:irua:93624 |
Serial |
2336 |
Permanent link to this record |
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Author |
Egoavil, R.; Huehn, S.; Jungbauer, M.; Gauquelin, N.; Béché, A.; Van Tendeloo, G.; Verbeeck; Moshnyaga, V. |
Title |
Phase problem in the B-site ordering of La2CoMnO6 : impact on structure and magnetism |
Type |
A1 Journal article |
Year |
2015 |
Publication |
Nanoscale |
Abbreviated Journal |
Nanoscale |
Volume |
7 |
Issue |
7 |
Pages |
9835-9843 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Epitaxial double perovskite La2CoMnO6 (LCMO) films were grown by metalorganic aerosol deposition on SrTiO3(111) substrates. A high Curie temperature, T-C = 226 K, and large magnetization close to saturation, M-S(5 K) = 5.8 mu(B)/f.u., indicate a 97% degree of B-site (Co,Mn) ordering within the film. The Co/Mn ordering was directly imaged at the atomic scale by scanning transmission electron microscopy with energy-dispersive X-ray spectroscopy (STEM-EDX). Local electron-energy-loss spectroscopy (EELS) measurements reveal that the B-sites are predominantly occupied by Co2+ and Mn4+ ions in quantitative agreement with magnetic data. Relatively small values of the (1/2 1/2 1/2) superstructure peak intensity, obtained by X-ray diffraction (XRD), point out the existence of ordered domains with an arbitrary phase relationship across the domain boundary. The size of these domains is estimated to be in the range 35-170 nm according to TEM observations and modelling the magnetization data. These observations provide important information towards the complexity of the cation ordering phenomenon and its implications on magnetism in double perovskites, and similar materials. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Cambridge |
Editor |
|
Language |
|
Wos |
000354983100060 |
Publication Date |
2015-05-05 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
|
ISSN |
2040-3364;2040-3372; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
7.367 |
Times cited |
37 |
Open Access |
|
Notes |
312483 ESTEEM2; FWO G004413N; 246102 IFOX; Hercules; esteem2_jra3 |
Approved |
Most recent IF: 7.367; 2015 IF: 7.394 |
Call Number |
c:irua:126423 c:irua:126423 |
Serial |
2586 |
Permanent link to this record |
|
|
|
Author |
Guzzinati, G.; Clark, L.; Béché, A.; Juchtmans, R.; Van Boxem, R.; Mazilu, M.; Verbeeck, J. |
Title |
Prospects for versatile phase manipulation in the TEM : beyond aberration correction |
Type |
A1 Journal article |
Year |
2015 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
151 |
Issue |
151 |
Pages |
85-93 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
In this paper we explore the desirability of a transmission electron microscope in which the phase of the electron wave can be freely controlled. We discuss different existing methods to manipulate the phase of the electron wave and their limitations. We show how with the help of current techniques the electron wave can already be crafted into specific classes of waves each having their own peculiar properties. Assuming a versatile phase modulation device is feasible, we explore possible benefits and methods that could come into existence borrowing from light optics where the so-called spatial light modulators provide programmable phase plates for quite some time now. We demonstrate that a fully controllable phase plate building on Harald Rose׳s legacy in aberration correction and electron optics in general would open an exciting field of research and applications. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000351237800012 |
Publication Date |
2014-10-22 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
|
ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.843 |
Times cited |
19 |
Open Access |
|
Notes |
278510 Vortex; Fwo; 312483 Esteem2; esteem2jra2; esteem2jra3 ECASJO_; |
Approved |
Most recent IF: 2.843; 2015 IF: 2.436 |
Call Number |
c:irua:121405 c:irua:121405UA @ admin @ c:irua:121405 |
Serial |
2731 |
Permanent link to this record |
|
|
|
Author |
Clark, L.; Béché, A.; Guzzinati, G.; Verbeeck, J. |
Title |
Quantitative measurement of orbital angular momentum in electron microscopy |
Type |
A1 Journal article |
Year |
2014 |
Publication |
Physical review : A : atomic, molecular and optical physics |
Abbreviated Journal |
Phys Rev A |
Volume |
89 |
Issue |
5 |
Pages |
053818 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Electron vortex beams have been predicted to enable atomic scale magnetic information measurement, via transfer of orbital angular momentum. Research so far has focused on developing production techniques and applications of these beams. However, methods to measure the outgoing orbital angular momentum distribution are also a crucial requirement towards this goal. Here, we use a method to obtain the orbital angular momentum decomposition of an electron beam, using a multipinhole interferometer. We demonstrate both its ability to accurately measure orbital angular momentum distribution, and its experimental limitations when used in a transmission electron microscope. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
Language |
|
Wos |
000335826300012 |
Publication Date |
2014-05-13 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
|
ISSN |
1050-2947;1094-1622; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.925 |
Times cited |
23 |
Open Access |
|
Notes |
7th Framework Program (FP7); ERC Starting Grant No. 278510- VORTEX 7th Framework Program (FP7) under a contract for an Integrated Infrastructure Initiative (Reference No. 312483 ESTEEM2). 7th Framework Program (FP7), ERC Grant No. 246791- COUNTATOMS. SP – 053818-1; esteem2jra3 ECASJO; |
Approved |
Most recent IF: 2.925; 2014 IF: 2.808 |
Call Number |
UA @ lucian @ c:irua:117093UA @ admin @ c:irua:117093 |
Serial |
2758 |
Permanent link to this record |
|
|
|
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. |
Address |
|
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 ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
|
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 |
Permanent link to this record |
|
|
|
Author |
Verbeeck, J.; Guzzinati, G.; Clark, L.; Juchtmans, R.; Van Boxem, R.; Tian, H.; Béché, A.; Lubk, A.; Van Tendeloo, G. |
Title |
Shaping electron beams for the generation of innovative measurements in the (S)TEM |
Type |
A1 Journal article |
Year |
2014 |
Publication |
Comptes rendus : physique |
Abbreviated Journal |
Cr Phys |
Volume |
15 |
Issue |
2-3 |
Pages |
190-199 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
In TEM, a typical goal consists of making a small electron probe in the sample plane in order to obtain high spatial resolution in scanning transmission electron microscopy. In order to do so, the phase of the electron wave is corrected to resemble a spherical wave compensating for aberrations in the magnetic lenses. In this contribution, we discuss the advantage of changing the phase of an electron wave in a specific way in order to obtain fundamentally different electron probes opening up new applications in the (S)TEM. We focus on electron vortex states as a specific family of waves with an azimuthal phase signature and discuss their properties, production and applications. The concepts presented here are rather general and also different classes of probes can be obtained in a similar fashion, showing that electron probes can be tuned to optimize a specific measurement or interaction. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Paris |
Editor |
|
Language |
|
Wos |
000334013600009 |
Publication Date |
2014-02-01 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
|
ISSN |
1631-0705; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.048 |
Times cited |
22 |
Open Access |
|
Notes |
Vortex ECASJO_; |
Approved |
Most recent IF: 2.048; 2014 IF: 2.035 |
Call Number |
UA @ lucian @ c:irua:116946UA @ admin @ c:irua:116946 |
Serial |
2992 |
Permanent link to this record |
|
|
|
Author |
Lubk, A.; Béché, A.; Verbeeck, J. |
Title |
Electron Microscopy of Probability Currents at Atomic Resolution |
Type |
A1 Journal article |
Year |
2015 |
Publication |
Physical review letters |
Abbreviated Journal |
Phys Rev Lett |
Volume |
115 |
Issue |
115 |
Pages |
176101 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Atomic resolution transmission electron microscopy records the spatially resolved scattered electron density to infer positions, density, and species of atoms. These data are indispensable for studying the relation between structure and properties in solids. Here, we show how this signal can be augmented by the lateral probability current of the scattered electrons in the object plane at similar resolutions and fields of view. The currents are reconstructed from a series of three atomic resolution TEM images recorded under a slight difference of perpendicular line foci. The technique does not rely on the coherence of the electron beam and can be used to reveal electric, magnetic, and strain fields with incoherent electron beams as well as correlations in inelastic transitions, such as electron magnetic chiral dichroism. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000363023700011 |
Publication Date |
2015-10-20 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
|
ISSN |
0031-9007;1079-7114; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
8.462 |
Times cited |
12 |
Open Access |
|
Notes |
J. V. and A. B. acknowledge funding from the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant No. 278510 VORTEX. The Qu-Ant- EM microscope was partly funded by the Hercules fund from the Flemish Government. All authors acknowledge financial support from the European Union under the Seventh Framework Program under a contract for an Integrated Infrastructure Initiative. Reference No. 312483- ESTEEM2. J. V. acknowledges funding from the FWO under Project No. G.0044.13N.; esteem2jra2; esteem2jra3 ECASJO_; |
Approved |
Most recent IF: 8.462; 2015 IF: 7.512 |
Call Number |
c:irua:129190 c:irua:129190UA @ admin @ c:irua:129190 |
Serial |
3954 |
Permanent link to this record |
|
|
|
Author |
Béché, A.; Rouviere, J.L.; Barnes, J.P.; Cooper, D. |
Title |
Strain measurement at the nanoscale : comparison between convergent beam electron diffraction, nano-beam electron diffraction, high resolution imaging and dark field electron holography |
Type |
A1 Journal article |
Year |
2013 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
131 |
Issue |
|
Pages |
10-23 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Convergent beam electron diffraction (CBED), nano-beam electron diffraction (NBED or NBD), high resolution imaging (HRTEM and HRSTEM) and dark field electron holography (DFEH or HoloDark) are five TEM based techniques able to quantitatively measure strain at the nanometer scale. In order to demonstrate the advantages and disadvantages of each technique, two samples composed of epitaxial silicon-germanium layers embedded in a silicon matrix have been investigated. The five techniques are then compared in terms of strain precision and accuracy, spatial resolution, field of view, mapping abilities and ease of performance and analysis. (C) 2013 Elsevier By. All rights reserved. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000322631200002 |
Publication Date |
2013-04-06 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
|
ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.843 |
Times cited |
73 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.843; 2013 IF: 2.745 |
Call Number |
UA @ lucian @ c:irua:109774 |
Serial |
3171 |
Permanent link to this record |
|
|
|
Author |
Wolf, D.; Rodriguez, L.A.; Béché, A.; Javon, E.; Serrano, L.; Magen, C.; Gatel, C.; Lubk, A.; Lichte, H.; Bals, S.; Van Tendeloo, G.; Fernández-Pacheco, A.; De Teresa, J.M.; Snoeck, E. |
Title |
3D Magnetic Induction Maps of Nanoscale Materials Revealed by Electron Holographic Tomography |
Type |
A1 Journal article |
Year |
2015 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
Volume |
27 |
Issue |
27 |
Pages |
6771-6778 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The investigation of three-dimensional (3D) ferromagnetic nanoscale materials constitutes one of the key research areas of the current magnetism roadmap, and carries great potential to impact areas such as data storage, sensing and biomagnetism. The properties of such nanostructures are closely connected with their 3D magnetic nanostructure, making their determination highly valuable. Up to now, quantitative 3D maps providing both the internal magnetic and electric configuration of the same specimen with high spatial resolution are missing. Here, we demonstrate the quantitative 3D reconstruction of the dominant axial component of the magnetic induction and electrostatic potential within a cobalt nanowire (NW) of 100 nm in diameter with spatial resolution below 10 nanometers by applying electron holographic tomography. The tomogram was obtained using a dedicated TEM sample holder for acquisition, in combination with advanced alignment and tomographic reconstruction routines. The powerful approach presented here is widely applicable to a broad range of 3D magnetic nanostructures and may trigger the progress of novel spintronic non-planar nanodevices. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000362920700037 |
Publication Date |
2015-09-08 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
|
ISSN |
0897-4756;1520-5002; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
9.466 |
Times cited |
50 |
Open Access |
OpenAccess |
Notes |
This work was supported by the European Union under the Seventh Framework Program under a contract for an Inte-grated Infrastructure Initiative Reference 312483-ESTEEM2. S.B. and A.B. gratefully acknowledge funding by ERC Starting grants number 335078 COLOURATOMS and number 278510 VORTEX. AF-P acknowledges an EPSRC Early Career fellowship and support from the Winton Foundation. E.S., C.G. and L.A. R. acknowledge the French ANR program for support though the project EMMA.; esteem2jra4; ECASJO;; ECAS_Sara; (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); |
Approved |
Most recent IF: 9.466; 2015 IF: 8.354 |
Call Number |
c:irua:129180 c:irua:129180 c:irua:129180 |
Serial |
3950 |
Permanent link to this record |
|
|
|
Author |
Juchtmans, R.; Béché, A.; Abakumov, A.; Batuk, M.; Verbeeck, J. |
Title |
Using electron vortex beams to determine chirality of crystals in transmission electron microscopy |
Type |
A1 Journal article |
Year |
2015 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
91 |
Issue |
91 |
Pages |
094112 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
We investigate electron vortex beams elastically scattered on chiral crystals. After deriving a general expression for the scattering amplitude of a vortex electron, we study its diffraction on point scatterers arranged on a helix. We derive a relation between the handedness of the helix and the topological charge of the electron vortex on one hand and the symmetry of the higher-order Laue zones in the diffraction pattern on the other for kinematically and dynamically scattered electrons. We then extend this to atoms arranged on a helix as found in crystals which belong to chiral space groups and propose a method to determine the handedness of such crystals by looking at the symmetry of the diffraction pattern. In contrast to alternative methods, our technique does not require multiple scattering, which makes it possible to also investigate extremely thin samples in which multiple scattering is suppressed. In order to verify the model, elastic scattering simulations are performed, and an experimental demonstration on Mn2Sb2O7 is given in which we find the sample to belong to the right-handed variant of its enantiomorphic pair. This demonstrates the usefulness of electron vortex beams to reveal the chirality of crystals in a transmission electron microscope and provides the required theoretical basis for further developments in this field. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000352017000002 |
Publication Date |
2015-03-27 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
|
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
54 |
Open Access |
|
Notes |
Fwo; 312483 Esteem2; 278510 Vortex; esteem2jra1; esteem2jra2 ECASJO_; |
Approved |
Most recent IF: 3.836; 2015 IF: 3.736 |
Call Number |
c:irua:125512 c:irua:125512 |
Serial |
3825 |
Permanent link to this record |
|
|
|
Author |
Béché, A.; Goris, B.; Freitag, B.; Verbeeck, J. |
Title |
Development of a fast electromagnetic beam blanker for compressed sensing in scanning transmission electron microscopy |
Type |
A1 Journal article |
Year |
2016 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
Volume |
108 |
Issue |
108 |
Pages |
093103 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The concept of compressed sensing was recently proposed to significantly reduce the electron dose in scanning transmission electron microscopy (STEM) while still maintaining the main features in the image. Here, an experimental setup based on an electromagnetic beam blanker placed in the condenser plane of a STEM is proposed. The beam blanker deflects the beam with a random pattern, while the scanning coils are moving the beam in the usual scan pattern. Experimental images at both the medium scale and high resolution are acquired and reconstructed based on a discrete cosine algorithm. The obtained results confirm that compressed sensing is highly attractive to limit beam damage in experimental STEM even though some remaining artifacts need to be resolved. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000375329200043 |
Publication Date |
2016-03-01 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
|
ISSN |
0003-6951 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.411 |
Times cited |
40 |
Open Access |
|
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 and under a contract for an Integrated Infrastructure Initiative (Reference No. 312483 ESTEEM2), from the GOA project SOLARPAINT and the POC project I13/009 from the University of Antwerp. B.G. acknowledges the Research Foundation Flanders (FWO Vlaanderen) for a postdoctoral research grant. The QuAnTem microscope was partially funded by the Hercules Foundation. We thank Zhaoliang Liao from the Mesa+ laboratory at the University of Twente for the perovskite test sample.; esteem2jra3 ECASJO; |
Approved |
Most recent IF: 3.411 |
Call Number |
c:irua:131895 c:irua:131895UA @ admin @ c:irua:131895 |
Serial |
4023 |
Permanent link to this record |
|
|
|
Author |
De Backer, A.; De Wael, A.; Gonnissen, J.; Martinez, G.T.; Béché, A.; MacArthur, K.E.; Jones, L.; Nellist, P.D.; Van Aert, S. |
Title |
Quantitative annular dark field scanning transmission electron microscopy for nanoparticle atom-counting: What are the limits? |
Type |
P1 Proceeding |
Year |
2015 |
Publication |
Journal of physics : conference series |
Abbreviated Journal |
|
Volume |
644 |
Issue |
644 |
Pages |
012034 |
Keywords |
P1 Proceeding; Electron microscopy for materials research (EMAT) |
Abstract |
Quantitative atomic resolution annular dark field scanning transmission electron microscopy (ADF STEM) has become a powerful technique for nanoparticle atom-counting. However, a lot of nanoparticles provide a severe characterisation challenge because of their limited size and beam sensitivity. Therefore, quantitative ADF STEM may greatly benefit from statistical detection theory in order to optimise the instrumental microscope settings such that the incoming electron dose can be kept as low as possible whilst still retaining single-atom precision. The principles of detection theory are used to quantify the probability of error for atom-counting. This enables us to decide between different image performance measures and to optimise the experimental detector settings for atom-counting in ADF STEM in an objective manner. To demonstrate this, ADF STEM imaging of an industrial catalyst has been conducted using the near-optimal detector settings. For this experiment, we discussed the limits for atom-counting diagnosed by combining a thorough statistical method and detailed image simulations. |
Address |
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Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000366826200034 |
Publication Date |
2015-10-13 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
Electron Microscopy and Analysis Group Conference (EMAG), JUN 02-JUL 02, 2015, Manchester, ENGLAND |
Series Volume |
|
Series Issue |
|
Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
|
ISSN |
1742-6588 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
Impact Factor |
|
Times cited |
|
Open Access |
|
Notes |
The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project funding (G.0368.15N, G.0369.15N, and G.0374.15N) and a PhD research grant to A De Backer. 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), ERC Starting Grant 278510 Vortex, and the UK Engineering and Physical Sciences Research Council (EP/K032518/1). The authors acknowledge Johnson-Matthey for providing the sample and PhD funding to K E MacArthur. A Rosenauer is acknowledged for providing the STEMsim program.; esteem2jra2; ECASJO; |
Approved |
Most recent IF: NA |
Call Number |
c:irua:130314 c:irua:130314 |
Serial |
4050 |
Permanent link to this record |
|
|
|
Author |
Clark, L.; Guzzinati, G.; Béché, A.; Lubk, A.; Verbeeck, J. |
Title |
Symmetry-constrained electron vortex propagation |
Type |
A1 Journal article |
Year |
2016 |
Publication |
Physical review A |
Abbreviated Journal |
Phys Rev A |
Volume |
93 |
Issue |
93 |
Pages |
063840 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Electron vortex beams hold great promise for development in transmission electron microscopy but have yet to be widely adopted. This is partly due to the complex set of interactions that occur between a beam carrying orbital angular momentum (OAM) and a sample. Herein, the system is simplified to focus on the interaction between geometrical symmetries, OAM, and topology. We present multiple simulations alongside experimental data to study the behavior of a variety of electron vortex beams after interacting with apertures of different symmetries and investigate the effect on their OAM and vortex structure, both in the far field and under free-space propagation. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000378197200006 |
Publication Date |
2016-06-23 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
|
ISSN |
2469-9926 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.925 |
Times cited |
7 |
Open Access |
|
Notes |
L.C., A.B., G.G., and J.V. acknowledge funding from the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant No. 278510—VORTEX. J.V. and A.L. acknowledge financial support from the European Union through the 7th Framework Program (FP7) under a contract for an Integrated Infrastructure Initiative (Reference No. 312483 ESTEEM2). The Qu-Ant-EM microscope was partly funded by the Hercules fund of the Flemish Government.; esteem2jra3; ECASJO; |
Approved |
Most recent IF: 2.925 |
Call Number |
c:irua:134086 c:irua:134086 |
Serial |
4090 |
Permanent link to this record |
|
|
|
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 ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
|
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 |
Permanent link to this record |
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|
|
Author |
Muller-Caspary, K.; Krause, F.F.; Grieb, T.; Loffler, S.; Schowalter, M.; Béché, A.; Galioit, V.; Marquardt, D.; Zweck, J.; Schattschneider, P.; Verbeeck, J.; Rosenauer, A. |
Title |
Measurement of atomic electric fields and charge densities from average momentum transfers using scanning transmission electron microscopy |
Type |
A1 Journal article |
Year |
2016 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
178 |
Issue |
178 |
Pages |
62-80 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
This study sheds light on the prerequisites, possibilities, limitations and interpretation of high-resolution differential phase contrast (DPC) imaging in scanning transmission electron microscopy (STEM). We draw particular attention to the well-established DPC technique based on segmented annular detectors and its relation to recent developments based on pixelated detectors. These employ the expectation value of the momentum transfer as a reliable measure of the angular deflection of the STEM beam induced by an electric field in the specimen. The influence of scattering and propagation of electrons within the specimen is initially discussed separately and then treated in terms of a two-state channeling theory. A detailed simulation study of GaN is presented as a function of specimen thickness and bonding. It is found that bonding effects are rather detectable implicitly, e.g., by characteristics of the momentum flux in areas between the atoms than by directly mapping electric fields and charge densities. For strontium titanate, experimental charge densities are compared with simulations and discussed with respect to experimental artifacts such as scan noise. Finally, we consider practical issues such as figures of merit for spatial and momentum resolution, minimum electron dose, and the mapping of larger-scale, built-in electric fields by virtue of data averaged over a crystal unit cell. We find that the latter is possible for crystals with an inversion center. Concerning the optimal detector design, this study indicates that a sampling of 5mrad per pixel is sufficient in typical applications, corresponding to approximately 10x10 available pixels. |
Address |
Institut fur Festkr perphysik, Universitat Bremen, Otto-Hahn-Allee 1, 28359 Bremen, Germany |
Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
English |
Wos |
000403862900009 |
Publication Date |
2016-05-12 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
|
ISSN |
0304-3991 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.843 |
Times cited |
93 |
Open Access |
|
Notes |
K.M.-C. acknowledges support from the Deutsche Forschungsgemeinschaft (DFG) under contract MU3660/1-1. This work was further supported by the DFG under contract RO2057/4-2 and O2057/11-1. J.V. and A.B. acknowledge funding from the European Research Council (ERC) under the 7th Framework Program (FP7), and ERC Starting Grant No. 278510-VORTEX. Experimental results are obtained on the Qu-Ant-EM microscope partly funded by the Hercules fund from the Flemish government. J.V. also acknowledges funding through a GOA project “Solarpaint” of the University of Antwerp. SL and PS acknowledge financial support by the Austrian Science Fund (FWF) under grants No. I543-N20 and J3732-N27. ECASJO_; |
Approved |
Most recent IF: 2.843 |
Call Number |
c:irua:134125UA @ admin @ c:irua:134125 |
Serial |
4098 |
Permanent link to this record |
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|
|
Author |
van den Bos, K.H.W.; Krause, F.F.; Béché, A.; Verbeeck, J.; Rosenauer, A.; Van Aert, S. |
Title |
Locating light and heavy atomic column positions with picometer precision using ISTEM |
Type |
A1 Journal article |
Year |
2016 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
172 |
Issue |
172 |
Pages |
75-81 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Recently, imaging scanning transmission electron microscopy (ISTEM) has been proposed as a promising new technique combining the advantages of conventional TEM (CTEM) and STEM [1]. The ability to visualize light and heavy elements together makes it a particularly interesting new, spatially incoherent imaging mode. Here, we evaluate this technique in term of precision with which atomic column locations can be measured. By using statistical parameter estimation theory, we will show that these locations can be accurately measured with a precision in the picometer range. Furthermore, a quantitative comparison is made with HAADF STEM imaging to investigate the advantages of ISTEM. |
Address |
|
Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000390600200009 |
Publication Date |
2016-10-09 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
|
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 |
The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0374.13N, G.0368.15N, G.0369.15N), and by a Ph.D. grant to K.H.W. van den Bos. 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 PbTiO3 test sample. |
Approved |
Most recent IF: 2.843 |
Call Number |
EMAT @ emat @ c:irua:136109UA @ admin @ c:irua:136109 |
Serial |
4288 |
Permanent link to this record |
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|
Author |
Cooper, D.; Denneulin, T.; Bernier, N.; Béché, A.; Rouvière, J.-L. |
Title |
Strain mapping of semiconductor specimens with nm-scale resolution in a transmission electron microscope |
Type |
A1 Journal article |
Year |
2016 |
Publication |
Micron |
Abbreviated Journal |
Micron |
Volume |
80 |
Issue |
80 |
Pages |
145-165 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The last few years have seen a great deal of progress in the development of transmission electron microscopy based techniques for strain mapping. New techniques have appeared such as dark field electron holography and nanobeam diffraction and better known ones such as geometrical phase analysis have been improved by using aberration corrected ultra-stable modern electron microscopes. In this paper we apply dark field electron holography, the geometrical phase analysis of high angle annular dark field scanning transmission electron microscopy images, nanobeam diffraction and precession diffraction, all performed at the state-of-the-art to five different types of semiconductor samples. These include a simple calibration structure comprising 10-nm-thick SiGe layers to benchmark the techniques. A SiGe recessed source and drain device has been examined in order to test their capabilities on 2D structures. Devices that have been strained using a nitride stressor have been examined to test the sensitivity of the different techniques when applied to systems containing low values of deformation. To test the techniques on modern semiconductors, an electrically tested device grown on a SOI wafer has been examined. Finally a GaN/AlN superlattice was tested in order to assess the different methods of measuring deformation on specimens that do not have a perfect crystalline structure. The different deformation mapping techniques have been compared to one another and the strengths and weaknesses of each are discussed. |
Address |
|
Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
Oxford |
Editor |
|
Language |
|
Wos |
000366770100018 |
Publication Date |
2015-09-15 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
|
ISSN |
0968-4328 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.98 |
Times cited |
50 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 1.98 |
Call Number |
UA @ lucian @ c:irua:136446 |
Serial |
4401 |
Permanent link to this record |
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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. |
Address |
|
Corporate Author |
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Thesis |
|
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 ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
|
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 |
Permanent link to this record |
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|
Author |
Jalabert, D.; Pelloux-Gervais, D.; Béché, A.; Hartmann, J.M.; Gergaud, P.; Rouvière, J.L.; Canut, B. |
Title |
Depth strain profile with sub-nm resolution in a thin silicon film using medium energy ion scattering |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Physica Status Solidi A-Applications And Materials Science |
Abbreviated Journal |
Phys Status Solidi A |
Volume |
209 |
Issue |
2 |
Pages |
265-267 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The depth strain profile in silicon from the Si (001) substrate to the surface of a 2 nm thick Si/12 nm thick SiGe/bulk Si heterostructure has been determined by medium energy ion scattering (MEIS). It shows with sub-nanometer resolution and high strain sensitivity that the thin Si cap presents residual compressive strain caused by Ge diffusion coming from the fully strained SiGe layer underneath. The strain state of the SiGe buffer have been checked by X-ray diffraction (XRD) and nano-beam electron diffraction (NBED) measurements. |
Address |
|
Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
|
Editor |
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Language |
|
Wos |
000303382700005 |
Publication Date |
2011-11-11 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
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Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
|
ISSN |
1862-6300; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.775 |
Times cited |
3 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 1.775; 2012 IF: 1.469 |
Call Number |
UA @ lucian @ c:irua:136430 |
Serial |
4497 |
Permanent link to this record |
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|
|
Author |
Cooper, D.; de la Peña, F.; Béché, A.; Rouvière, J.-L.; Servanton, G.; Pantel, R.; Morin, P. |
Title |
Field mapping with nanometer-scale resolution for the next generation of electronic devices |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Nano letters |
Abbreviated Journal |
Nano Lett |
Volume |
11 |
Issue |
11 |
Pages |
4585-4590 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
In order to improve the performance of todays nanoscaled semiconductor devices, characterization techniques that can provide information about the position and activity of dopant atoms and the strain fields are essential. Here we demonstrate that by using a modern transmission electron microscope it is possible to apply multiple techniques to advanced materials systems in order to provide information about the structure, fields, and composition with nanometer-scale resolution. Off-axis electron holography has been used to map the active dopant potentials in state-of-the-art semiconductor devices with 1 nm resolution. These dopant maps have been compared to electron energy loss spectroscopy maps that show the positions of the dopant atoms. The strain fields in the devices have been measured by both dark field electron holography and nanobeam electron diffraction. |
Address |
|
Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
Washington |
Editor |
|
Language |
|
Wos |
000296674700014 |
Publication Date |
2011-10-05 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
|
ISSN |
1530-6984 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
12.712 |
Times cited |
12 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 12.712; 2011 IF: 13.198 |
Call Number |
UA @ lucian @ c:irua:136369 |
Serial |
4499 |
Permanent link to this record |