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Records |
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Author |
Guzzinati, G.; Clark, L.; Béché, A.; Verbeeck, J. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
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Title |
Measuring the orbital angular momentum of electron beams |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Physical review : A : atomic, molecular and optical physics |
Abbreviated Journal |
Phys Rev A |
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Volume |
89 |
Issue |
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Pages |
025803 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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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. |
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Place of Publication |
Lancaster, Pa |
Editor ![sorted by Editor field, ascending order (up)](img/sort_asc.gif) |
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Language |
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Wos |
000332224100014 |
Publication Date |
2014-02-13 |
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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 |
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ISSN |
1050-2947;1094-1622; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.925 |
Times cited |
42 |
Open Access |
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Notes |
Vortex; FP7; Countatoms; ESTEEM2; esteem2jra3 ECASJO; |
Approved |
Most recent IF: 2.925; 2014 IF: 2.808 |
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Call Number |
UA @ lucian @ c:irua:114577UA @ admin @ c:irua:114577 |
Serial |
1972 |
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Permanent link to this record |
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Author |
Verbeeck, J.; Tian, H.; Béché, A. |
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Title |
A new way of producing electron vortex probes for STEM |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
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Volume |
113 |
Issue |
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Pages |
83-87 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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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. |
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Thesis |
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Publisher |
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Place of Publication |
Amsterdam |
Editor ![sorted by Editor field, ascending order (up)](img/sort_asc.gif) |
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Language |
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Wos |
000300554400002 |
Publication Date |
2011-10-31 |
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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 |
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ISSN |
0304-3991; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.843 |
Times cited |
62 |
Open Access |
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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 |
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Call Number |
UA @ lucian @ c:irua:93624UA @ admin @ c:irua:93624 |
Serial |
2336 |
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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. |
![goto web page url](http://nano.uantwerpen.be/nanorefs/img/www.gif)
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Title |
Phase problem in the B-site ordering of La2CoMnO6 : impact on structure and magnetism |
Type |
A1 Journal article |
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Year |
2015 |
Publication |
Nanoscale |
Abbreviated Journal |
Nanoscale |
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Volume |
7 |
Issue |
7 |
Pages |
9835-9843 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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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. |
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Place of Publication |
Cambridge |
Editor ![sorted by Editor field, ascending order (up)](img/sort_asc.gif) |
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Language |
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Wos |
000354983100060 |
Publication Date |
2015-05-05 |
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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 |
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ISSN |
2040-3364;2040-3372; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
7.367 |
Times cited |
37 |
Open Access |
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Notes |
312483 ESTEEM2; FWO G004413N; 246102 IFOX; Hercules; esteem2_jra3 |
Approved |
Most recent IF: 7.367; 2015 IF: 7.394 |
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Call Number |
c:irua:126423 c:irua:126423 |
Serial |
2586 |
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Permanent link to this record |
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Author |
Guzzinati, G.; Clark, L.; Béché, A.; Juchtmans, R.; Van Boxem, R.; Mazilu, M.; Verbeeck, J. |
![goto web page url](http://nano.uantwerpen.be/nanorefs/img/www.gif)
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Title |
Prospects for versatile phase manipulation in the TEM : beyond aberration correction |
Type |
A1 Journal article |
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Year |
2015 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
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Volume |
151 |
Issue |
151 |
Pages |
85-93 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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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. |
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Corporate Author |
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Publisher |
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Place of Publication |
Amsterdam |
Editor ![sorted by Editor field, ascending order (up)](img/sort_asc.gif) |
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Language |
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Wos |
000351237800012 |
Publication Date |
2014-10-22 |
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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 |
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ISSN |
0304-3991; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.843 |
Times cited |
19 |
Open Access |
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Notes |
278510 Vortex; Fwo; 312483 Esteem2; esteem2jra2; esteem2jra3 ECASJO_; |
Approved |
Most recent IF: 2.843; 2015 IF: 2.436 |
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Call Number |
c:irua:121405 c:irua:121405UA @ admin @ c:irua:121405 |
Serial |
2731 |
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Permanent link to this record |
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Author |
Clark, L.; Béché, A.; Guzzinati, G.; Verbeeck, J. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
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Title |
Quantitative measurement of orbital angular momentum in electron microscopy |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Physical review : A : atomic, molecular and optical physics |
Abbreviated Journal |
Phys Rev A |
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Volume |
89 |
Issue |
5 |
Pages |
053818 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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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. |
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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 ![sorted by Editor field, ascending order (up)](img/sort_asc.gif) |
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Language |
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Wos |
000335826300012 |
Publication Date |
2014-05-13 |
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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 |
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ISSN |
1050-2947;1094-1622; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.925 |
Times cited |
23 |
Open Access |
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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 |
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Call Number |
UA @ lucian @ c:irua:117093UA @ admin @ c:irua:117093 |
Serial |
2758 |
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Permanent link to this record |
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Author |
Martinez, G.T.; Jones, L.; de Backer, A.; Béché, A.; Verbeeck, J.; Van Aert, S.; Nellist, P.D. |
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Title |
Quantitative STEM normalisation : the importance of the electron flux |
Type |
A1 Journal article |
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Year |
2015 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
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Volume |
159 |
Issue |
159 |
Pages |
46-58 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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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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Publisher |
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Place of Publication |
Amsterdam |
Editor ![sorted by Editor field, ascending order (up)](img/sort_asc.gif) |
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Language |
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Wos |
000366220000006 |
Publication Date |
2015-08-01 |
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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 |
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ISSN |
0304-3991; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.843 |
Times cited |
27 |
Open Access |
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Notes |
246791 Countatoms; 278510 Vortex; 312483 Esteem2; Fwo G036815; G036915; G037413; G004413; esteem2ta ECASJO; |
Approved |
Most recent IF: 2.843; 2015 IF: 2.436 |
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Call Number |
c:irua:127293 c:irua:127293UA @ admin @ c:irua:127293 |
Serial |
2762 |
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Permanent link to this record |
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Author |
Lubk, A.; Béché, A.; Verbeeck, J. |
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Title |
Electron Microscopy of Probability Currents at Atomic Resolution |
Type |
A1 Journal article |
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Year |
2015 |
Publication |
Physical review letters |
Abbreviated Journal |
Phys Rev Lett |
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Volume |
115 |
Issue |
115 |
Pages |
176101 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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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. |
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Place of Publication |
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Editor ![sorted by Editor field, ascending order (up)](img/sort_asc.gif) |
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Language |
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Wos |
000363023700011 |
Publication Date |
2015-10-20 |
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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 |
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ISSN |
0031-9007;1079-7114; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
8.462 |
Times cited |
12 |
Open Access |
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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 |
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Call Number |
c:irua:129190 c:irua:129190UA @ admin @ c:irua:129190 |
Serial |
3954 |
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Permanent link to this record |
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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. |
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Title |
3D Magnetic Induction Maps of Nanoscale Materials Revealed by Electron Holographic Tomography |
Type |
A1 Journal article |
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Year |
2015 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
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Volume |
27 |
Issue |
27 |
Pages |
6771-6778 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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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. |
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Editor ![sorted by Editor field, ascending order (up)](img/sort_asc.gif) |
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Language |
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Wos |
000362920700037 |
Publication Date |
2015-09-08 |
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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 |
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ISSN |
0897-4756;1520-5002; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
9.466 |
Times cited |
50 |
Open Access |
OpenAccess |
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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 |
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Call Number |
c:irua:129180 c:irua:129180 c:irua:129180 |
Serial |
3950 |
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Permanent link to this record |
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Author |
Juchtmans, R.; Béché, A.; Abakumov, A.; Batuk, M.; Verbeeck, J. |
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Title |
Using electron vortex beams to determine chirality of crystals in transmission electron microscopy |
Type |
A1 Journal article |
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Year |
2015 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
91 |
Issue |
91 |
Pages |
094112 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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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. |
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Editor ![sorted by Editor field, ascending order (up)](img/sort_asc.gif) |
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Language |
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Wos |
000352017000002 |
Publication Date |
2015-03-27 |
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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 |
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ISSN |
1098-0121;1550-235X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.836 |
Times cited |
54 |
Open Access |
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Notes |
Fwo; 312483 Esteem2; 278510 Vortex; esteem2jra1; esteem2jra2 ECASJO_; |
Approved |
Most recent IF: 3.836; 2015 IF: 3.736 |
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Call Number |
c:irua:125512 c:irua:125512 |
Serial |
3825 |
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Permanent link to this record |
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Author |
Béché, A.; Goris, B.; Freitag, B.; Verbeeck, J. |
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Title |
Development of a fast electromagnetic beam blanker for compressed sensing in scanning transmission electron microscopy |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
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Volume |
108 |
Issue |
108 |
Pages |
093103 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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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. |
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Editor ![sorted by Editor field, ascending order (up)](img/sort_asc.gif) |
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Wos |
000375329200043 |
Publication Date |
2016-03-01 |
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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 |
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ISSN |
0003-6951 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.411 |
Times cited |
40 |
Open Access |
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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 |
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Call Number |
c:irua:131895 c:irua:131895UA @ admin @ c:irua:131895 |
Serial |
4023 |
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Permanent link to this record |
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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. |
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Title |
Quantitative annular dark field scanning transmission electron microscopy for nanoparticle atom-counting: What are the limits? |
Type |
P1 Proceeding |
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Year |
2015 |
Publication |
Journal of physics : conference series |
Abbreviated Journal |
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Volume |
644 |
Issue |
644 |
Pages |
012034 |
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Keywords |
P1 Proceeding; Electron microscopy for materials research (EMAT) |
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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. |
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Editor ![sorted by Editor field, ascending order (up)](img/sort_asc.gif) |
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Language |
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Wos |
000366826200034 |
Publication Date |
2015-10-13 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
Electron Microscopy and Analysis Group Conference (EMAG), JUN 02-JUL 02, 2015, Manchester, ENGLAND |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1742-6588 |
ISBN |
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Additional Links |
UA library record; WoS full record |
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Impact Factor |
|
Times cited |
|
Open Access |
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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 |
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Call Number |
c:irua:130314 c:irua:130314 |
Serial |
4050 |
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Permanent link to this record |
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Author |
Clark, L.; Guzzinati, G.; Béché, A.; Lubk, A.; Verbeeck, J. |
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Title |
Symmetry-constrained electron vortex propagation |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Physical review A |
Abbreviated Journal |
Phys Rev A |
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Volume |
93 |
Issue |
93 |
Pages |
063840 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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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. |
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Corporate Author |
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Editor ![sorted by Editor field, ascending order (up)](img/sort_asc.gif) |
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Wos |
000378197200006 |
Publication Date |
2016-06-23 |
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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 |
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ISSN |
2469-9926 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.925 |
Times cited |
7 |
Open Access |
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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 |
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Call Number |
c:irua:134086 c:irua:134086 |
Serial |
4090 |
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Permanent link to this record |
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Author |
Béché, A.; Juchtmans, R.; Verbeeck, J. |
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Title |
Efficient creation of electron vortex beams for high resolution STEM imaging |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
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Volume |
178 |
Issue |
178 |
Pages |
12-19 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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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. |
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Address |
EMAT, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium |
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Corporate Author |
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Place of Publication |
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Editor ![sorted by Editor field, ascending order (up)](img/sort_asc.gif) |
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Language |
English |
Wos |
000403862900003 |
Publication Date |
2016-05-10 |
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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 |
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ISSN |
0304-3991 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.843 |
Times cited |
30 |
Open Access |
OpenAccess |
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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 |
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Call Number |
c:irua:134085 c:irua:134085UA @ admin @ c:irua:134085 |
Serial |
4094 |
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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. |
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Title |
Measurement of atomic electric fields and charge densities from average momentum transfers using scanning transmission electron microscopy |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
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Volume |
178 |
Issue |
178 |
Pages |
62-80 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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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. |
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Address |
Institut fur Festkr perphysik, Universitat Bremen, Otto-Hahn-Allee 1, 28359 Bremen, Germany |
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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 ![sorted by Editor field, ascending order (up)](img/sort_asc.gif) |
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Language |
English |
Wos |
000403862900009 |
Publication Date |
2016-05-12 |
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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 |
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ISSN |
0304-3991 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.843 |
Times cited |
93 |
Open Access |
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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 |
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Call Number |
c:irua:134125UA @ admin @ c:irua:134125 |
Serial |
4098 |
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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. |
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Title |
Locating light and heavy atomic column positions with picometer precision using ISTEM |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
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Volume |
172 |
Issue |
172 |
Pages |
75-81 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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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. |
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Corporate Author |
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Editor ![sorted by Editor field, ascending order (up)](img/sort_asc.gif) |
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Language |
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Wos |
000390600200009 |
Publication Date |
2016-10-09 |
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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 |
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ISSN |
0304-3991 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.843 |
Times cited |
8 |
Open Access |
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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 |
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Call Number |
EMAT @ emat @ c:irua:136109UA @ admin @ c:irua:136109 |
Serial |
4288 |
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Permanent link to this record |
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Author |
Lepot, K.; Addad, A.; Knoll, A.H.; Wang, J.; Troadec, D.; Béché, A.; Javaux, E.J. |
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Title |
Iron minerals within specific microfossil morphospecies of the 1.88 Ga Gunflint Formation |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Nature communications |
Abbreviated Journal |
Nat Commun |
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Volume |
8 |
Issue |
8 |
Pages |
14890 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
Problematic microfossils dominate the palaeontological record between the Great Oxidation Event 2.4 billion years ago (Ga) and the last Palaeoproterozoic iron formations, deposited 500–600 million years later. These fossils are often associated with iron-rich sedimentary rocks, but their affinities, metabolism, and, hence, their contributions to Earth surface oxidation and Fe deposition remain unknown. Here we show that specific microfossil populations of the 1.88 Ga Gunflint Iron Formation contain Fe-silicate and Fe-carbonate nanocrystal concentrations in cell interiors. Fe minerals are absent in/on all organically preserved cell walls. These features are consistent with in vivo intracellular Fe biomineralization, with subsequent in situ recrystallization, but contrast with known patterns of post-mortem Fe mineralization. The Gunflint populations that display relatively large cells (thick-walled spheres, filament-forming rods) and intra-microfossil Fe minerals are consistent with oxygenic photosynthesizers but not with other Fe-mineralizing microorganisms studied so far. Fe biomineralization may have protected oxygenic photosynthesizers against Fe2+ toxicity during the Palaeoproterozoic. |
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Corporate Author |
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Place of Publication |
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Editor ![sorted by Editor field, ascending order (up)](img/sort_asc.gif) |
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Language |
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Wos |
000397129900001 |
Publication Date |
2017-03-23 |
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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 |
|
Edition |
|
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ISSN |
2041-1723 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
12.124 |
Times cited |
20 |
Open Access |
OpenAccess |
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Notes |
We thank J.-P. Cullus (thin sections), G. Spronck and C. Henrist (TEM), M. Cabié and C. Dominici (FIB), S. Bernard and C. Karunakaran (STXM), F. Bourdelle and G. Ji (EELS), P. Recourt (SEM). This study was co-funded by FRFC Grant no. 2.4558.09F (E.J.J.), CNRS-INSU (K.L.), FNRS (K.L.), ERC StG ELiTE Grant no. 308074 (E.J.J.), BELSPO IAP PLANET TOPERS (E.J.J.), NASA Astrobiology Institute (A.H.K.), Conseil Régional du Nord-Pas de Calais+European Regional Development Fund+CNRS-INSU (TEM in Lille), FP7-ESMI no. 262348 (TEM at EMAT Antwerp) and ANR-15-CE31-0003-01 (M6fossils, K.L.). We thank Noah Planavsky and two anonymous reviewers for thorough reviews that helped improve the paper. |
Approved |
Most recent IF: 12.124 |
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Call Number |
EMAT @ emat @ c:irua:141919 |
Serial |
4536 |
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Permanent link to this record |
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Author |
Guzzinati, G.; Béché, A.; Lourenço-Martins, H.; Martin, J.; Kociak, M.; Verbeeck, J. |
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Title |
Probing the symmetry of the potential of localized surface plasmon resonances with phase-shaped electron beams |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Nature communications |
Abbreviated Journal |
Nat Commun |
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Volume |
8 |
Issue |
8 |
Pages |
14999 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
Plasmonics, the science and technology of the interaction of light with metallic objects, is fundamentally changing the way we can detect, generate and manipulate light. Although the field is progressing swiftly, thanks to the availability of nanoscale manufacturing and analysis methods, fundamental properties such as the plasmonic excitations’ symmetries cannot be accessed directly, leading to a partial, sometimes incorrect, understanding of their properties. Here we overcome this limitation by deliberately shaping the wave function of an electron beam to match a plasmonic excitations’ symmetry in a modified transmission electron microscope. We show experimentally and theoretically that this offers selective detection of specific plasmon modes within metallic nanoparticles, while excluding modes with other symmetries. This method resembles the widespread use of polarized light for the selective excitation of plasmon modes with the advantage of locally probing the response of individual plasmonic objects and a far wider range of symmetry selection criteria. |
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Corporate Author |
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Publisher |
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Place of Publication |
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Editor ![sorted by Editor field, ascending order (up)](img/sort_asc.gif) |
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Language |
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Wos |
000399084300001 |
Publication Date |
2017-04-12 |
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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 |
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ISSN |
2041-1723 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
12.124 |
Times cited |
84 |
Open Access |
OpenAccess |
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Notes |
; We thank F.J. Garcia de Abajo and D.M. Ugarte for interesting and fruitful discussion. This work was supported by funding from the European Research Council under the 7th Framework Program (FP7) ERC Starting Grant 278510 VORTEX. Financial support from the European Union under the Framework 7 program under a contract for an Integrated Infrastructure Initiative (Reference number 312483 ESTEEM2) is also gratefully acknowledged. Aluminum nanostructures were fabricated using the Nanomat nanofabrication facility. ; |
Approved |
Most recent IF: 12.124 |
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Call Number |
EMAT @ emat @ c:irua:142205UA @ admin @ c:irua:142205 |
Serial |
4548 |
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Permanent link to this record |
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Author |
Bliokh, K.Y.; Ivanov, I.P.; Guzzinati, G.; Clark, L.; Van Boxem, R.; Béché, A.; Juchtmans, R.; Alonso, M.A.; Schattschneider, P.; Nori, F.; Verbeeck, J. |
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Title |
Theory and applications of free-electron vortex states |
Type |
A1 Journal article |
|
Year |
2017 |
Publication |
Physics reports |
Abbreviated Journal |
Phys Rep |
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Volume |
690 |
Issue |
690 |
Pages |
1-70 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Both classical and quantum waves can form vortices: with helical phase fronts and azimuthal current densities. These features determine the intrinsic orbital angular momentum carried by localized vortex states. In the past 25 years, optical vortex beams have become an inherent part of modern optics, with many remarkable achievements and applications. In the past decade, it has been realized and demonstrated that such vortex beams or wavepackets can also appear in free electron waves, in particular, in electron microscopy. Interest in free-electron vortex states quickly spread over different areas of physics: from basic aspects of quantum mechanics, via applications for fine probing of matter (including individual atoms), to high-energy particle collision and radiation processes. Here we provide a comprehensive review of theoretical and experimental studies in this emerging field of research. We describe the main properties of electron vortex states, experimental achievements and possible applications within transmission electron microscopy, as well as the possible role of vortex electrons in relativistic and high-energy processes. We aim to provide a balanced description including a pedagogical introduction, solid theoretical basis, and a wide range of practical details. Special attention is paid to translate theoretical insights into suggestions for future experiments, in electron microscopy and beyond, in any situation where free electrons occur. |
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Place of Publication |
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Editor ![sorted by Editor field, ascending order (up)](img/sort_asc.gif) |
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Language |
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Wos |
000406169900001 |
Publication Date |
2017-05-29 |
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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 |
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ISSN |
0370-1573 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
17.425 |
Times cited |
210 |
Open Access |
OpenAccess |
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Notes |
AFOSR, FA9550-14-1-0040 ; CREST, JPMJCR1676 ; Portuguese Fundação para a Ciência e a Tecnologia (FCT), IF/00989/2014/CP1214/CT0004 ; Austrian Science Fund, I543-N20 ; ERC, 278510 VORTEX ; We acknowledge discussions with Mark R. Dennis and Andrei Afanasev. This work was supported by the RIKEN Interdisciplinary Theoretical Science Research Group (iTHES) Project, the Multi-University Research Initiative (MURI) Center for Dynamic Magneto-Optics via the Air Force Office of Scientific Research (AFOSR) (Grant No. FA9550-14-1-0040), Grant-in-Aid for Scientific Research (A), Core Research for Evolutionary Science and Technology (CREST), the John Templeton Foundation, the Australian Research Council, the Portuguese Funda¸c˜ao para a Ciˆencia e a Tecnologia (FCT) (contract IF/00989/2014/CP1214/CT0004 under the IF2014 Program), contracts UID/FIS/00777/2013 and CERN/FIS-NUC/0010/2015 (partially funded through POCTI, COMPETE, QREN, and the European Union), Austrian Science Fund Grant No. I543-N20, the European Research Council under the 7th Framework Program (FP7) (ERC Starting Grant No. 278510 VORTEX), and FWO PhD Fellowship grants (Aspirant Fonds Wetenschappelijk OnderzoekVlaanderen). |
Approved |
Most recent IF: 17.425 |
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Call Number |
EMAT @ emat @ c:irua:143262 |
Serial |
4574 |
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Permanent link to this record |
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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. |
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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 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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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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Editor ![sorted by Editor field, ascending order (up)](img/sort_asc.gif) |
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Wos |
000411170800022 |
Publication Date |
2017-06-03 |
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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 |
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ISSN |
0304-3991 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.843 |
Times cited |
34 |
Open Access |
OpenAccess |
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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 |
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Call Number |
EMAT @ emat @ c:irua:144435UA @ admin @ c:irua:144435 |
Serial |
4620 |
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Permanent link to this record |
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Author |
Kleibert, A.; Balan, A.; Yanes, R.; Derlet, P.M.; Vaz, C.A.F.; Timm, M.; Fraile Rodríguez, A.; Béché, A.; Verbeeck, J.; Dhaka, R.S.; Radovic, M.; Nowak, U.; Nolting, F. |
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Title |
Direct observation of enhanced magnetism in individual size- and shape-selected 3d transition metal nanoparticles |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
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Volume |
95 |
Issue |
95 |
Pages |
195404 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Magnetic nanoparticles are critical building blocks for future technologies ranging from nanomedicine to spintronics. Many related applications require nanoparticles with tailored magnetic properties. However, despite significant efforts undertaken towards this goal, a broad and poorly understood dispersion of magnetic properties is reported, even within monodisperse samples of the canonical ferromagnetic 3d transition metals. We address this issue by investigating the magnetism of a large number of size- and shape-selected, individual nanoparticles of Fe, Co, and Ni using a unique set of complementary characterization techniques. At room temperature, only superparamagnetic behavior is observed in our experiments for all Ni nanoparticles within the investigated sizes, which range from 8 to 20 nm. However, Fe and Co nanoparticles can exist in two distinct magnetic states at any size in this range: (i) a superparamagnetic state, as expected from the bulk and surface anisotropies known for the respective materials and as observed for Ni, and (ii) a state with unexpected stable magnetization at room temperature. This striking state is assigned to significant modifications of the magnetic properties arising from metastable lattice defects in the core of the nanoparticles, as concluded by calculations and atomic structural characterization. Also related with the structural defects, we find that the magnetic state of Fe and Co nanoparticles can be tuned by thermal treatment enabling one to tailor their magnetic properties for applications. This paper demonstrates the importance of complementary single particle investigations for a better understanding of nanoparticle magnetism and for full exploration of their potential for applications. |
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Wos |
000400665300002 |
Publication Date |
2017-05-05 |
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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 |
|
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ISSN |
2469-9950 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.836 |
Times cited |
21 |
Open Access |
OpenAccess |
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Notes |
We thank A. Weber, R. Schelldorfer, and J. Krbanjevic (Paul Scherrer Institut) for technical assistance. This paper was supported by the Swiss Nanoscience Institute, University of Basel. A.F.R. acknowledges support from the MICIIN “Ramón y Cajal” Programme. A.B. and J.V. acknowledge funding from the European Union under the European Research Council (ERC) Starting Grant No. 278510 VORTEX and under a contract for Integrated Infrastructure Initiative ESTEEM2 No. 312483. R.Y. and U.N. thank the Deutsche Forschungsgemeinschaft for financial support via Sonderforschungsbereich 1214. Part of this work was performed at the Surface/Interface: Microscopy (SIM) beamline of the Swiss Light Source, Paul Scherrer Institut, Villigen, Switzerland. |
Approved |
Most recent IF: 3.836 |
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Call Number |
EMAT @ emat @ c:irua:143634UA @ admin @ c:irua:143634 |
Serial |
4575 |
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Permanent link to this record |
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Author |
Verbeeck, J.; Béché, A.; Müller-Caspary, K.; Guzzinati, G.; Luong, M.A.; Den Hertog, M. |
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Title |
Demonstration of a 2 × 2 programmable phase plate for electrons |
Type |
A1 Journal article |
|
Year |
2018 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
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Volume |
190 |
Issue |
|
Pages |
58-65 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
First results on the experimental realisation of a 2 × 2 programmable phase plate for electrons are presented. The design consists of an array of electrostatic elements that influence the phase of electron waves passing through 4 separately controllable aperture holes. This functionality is demonstrated in a conventional transmission electron microscope operating at 300 kV and results are in very close agreement with theoretical predictions. The dynamic creation of a set of electron probes with different phase symmetry is demonstrated, thereby bringing adaptive optics in TEM one step closer to reality. The limitations of the current design and how to overcome these in the future are discussed. Simulations show how further evolved versions of the current proof of concept might open new and exciting application prospects for beam shaping and aberration correction. |
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Editor ![sorted by Editor field, ascending order (up)](img/sort_asc.gif) |
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Language |
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Wos |
000432868800007 |
Publication Date |
2018-04-18 |
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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 |
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ISSN |
0304-3991 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.843 |
Times cited |
73 |
Open Access |
Not_Open_Access: Available from 19.04.2020
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Notes |
J.V. and A.B. acknowledge funding from the Fund for Scientific Research Flanders FWO project G093417N and the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant 278510 VORTEX and ERC proof of concept project DLV-789598 ADAPTEM. The Qu-Ant-EM microscope used in this work was partly funded by the Hercules fund from the Flemish Government. MdH acknowledges financial support from the ANRCOSMOS (ANR-12-JS10-0002). MdH and ML acknowledge funding from the Laboratoire d’excellence LANEF in Grenoble (ANR-10-LABX-51-01). |
Approved |
Most recent IF: 2.843 |
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Call Number |
EMAT @ emat @c:irua:150459UA @ admin @ c:irua:150459 |
Serial |
4920 |
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Permanent link to this record |
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Author |
Altantzis, T.; Lobato, I.; De Backer, A.; Béché, A.; Zhang, Y.; Basak, S.; Porcu, M.; Xu, Q.; Sánchez-Iglesias, A.; Liz-Marzán, L.M.; Van Tendeloo, G.; Van Aert, S.; Bals, S. |
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Title |
Three-Dimensional Quantification of the Facet Evolution of Pt Nanoparticles in a Variable Gaseous Environment |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Nano letters |
Abbreviated Journal |
Nano Lett |
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Volume |
19 |
Issue |
19 |
Pages |
477-481 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
Pt nanoparticles play an essential role in a wide variety of catalytic reactions. The activity of the particles strongly depends on their three-dimensional (3D) structure and exposed facets, as well as on the reactive environment. High-resolution electron microscopy has often been used to characterize nanoparticle catalysts but unfortunately most observations so far have been either performed in vacuum and/or using conventional (2D) in situ microscopy. The latter however does not provide direct 3D morphological information. We have implemented a quantitative methodology to measure variations of the 3D atomic structure of nanoparticles under the flow of a selected gas. We were thereby able to quantify refaceting of Pt nanoparticles with atomic resolution during various oxidation−reduction cycles. In a H2 environment, a more faceted surface morphology of the particles was observed with {100} and {111} planes being dominant. On the other hand, in O2 the percentage of {100} and {111} facets decreased and a significant increase of higher order facets was found, resulting in a more rounded morphology. This methodology opens up new opportunities toward in situ characterization of catalytic nanoparticles because for the first time it enables one to directly measure 3D morphology variations at the atomic scale in a specific gaseous reaction environment. |
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Wos |
000455561300061 |
Publication Date |
2019-01-09 |
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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 |
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ISSN |
1530-6984 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
12.712 |
Times cited |
82 |
Open Access |
OpenAccess |
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Notes |
This work was supported by the European Research Council (Grant 335078 COLOURATOM to S.B. and Grant 770887 PICOMETRICS to S.V.A.). The authors acknowledge funding from the European Commission Grant (EUSMI 731019 to S.B., L.M.L.-M., and Q.X. and MUMMERING 765604 to S.B. and Q.X.). The authors gratefully acknowledge funding from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0368.15N, G.0369.15N, and G.0267.18N), postdoctoral grants to T.A. and A.D.B, and an FWO [PEGASUS]2 Marie Sklodowska-Curie fellowship to Y.Z. (12U4917N). L.M.L.-M. acknowledges funding from the Spanish Ministerio de Economía y Competitividad (Grant MAT2017-86659-R). We gratefully acknowledge the support of NVIDIA Corporation with the donation of the Titan X Pascal GPU used for this research. ecas_sara Realnano 815128; sygma |
Approved |
Most recent IF: 12.712 |
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Call Number |
EMAT @ emat @UA @ admin @ c:irua:156390 |
Serial |
5150 |
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Permanent link to this record |
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Author |
Vanrompay, H.; Bladt, E.; Albrecht, W.; Béché, A.; Zakhozheva, M.; Sánchez-Iglesias, A.; Liz-Marzán, L.M.; Bals, S. |
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Title |
3D characterization of heat-induced morphological changes of Au nanostars by fast in situ electron tomography |
Type |
A1 Journal article |
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Year |
2018 |
Publication |
Nanoscale |
Abbreviated Journal |
Nanoscale |
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Volume |
10 |
Issue |
10 |
Pages |
22792-22801 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
A thorough understanding of the thermal stability and potential reshaping of anisotropic gold nanostars is required for various potential applications. Combination of a tomographic heating holder with fast tilt series acquisition has been used to monitor temperature-induced morphological changes of Au nanostars. The outcome of our 3D investigations can be used as an input for boundary element method simulations, enabling us to investigate the influence of reshaping on the nanostars’ plasmonic properties. Our work leads to a better understanding of the mechanism behind thermal reshaping. In addition, the approach presented here is generic and can hence be applied to a wide variety of nanoparticles made of different materials and with arbitrary morphology. |
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Wos |
000453248100010 |
Publication Date |
2018-11-28 |
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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 |
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ISSN |
2040-3364 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
7.367 |
Times cited |
55 |
Open Access |
OpenAccess |
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Notes |
H.V. acknowledges financial support by the Research Foundation Flanders (FWO grant 1S32617N). E.B. acknowledges a post-doctoral grant from the Research Foundation Flanders (FWO, Belgium). W.A. acknowledges an Individual Fellowship funded by the Marie Sklodowska-Curie Actions (MSCA) in Horizon 2020. The authors acknowledge funding from European Commission Grant (EUSMI 731019 to S.B., L.M.L.-M. and M.Z. and MUMMERING 765604 to S.B. and M.Z.). S.B. acknowledges financial support from European Research Council (ERC Starting Grant #335078- COLOURATOMS).; Ecas_sara |
Approved |
Most recent IF: 7.367 |
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Call Number |
EMAT @ emat @c:irua:155718UA @ admin @ c:irua:155718 |
Serial |
5071 |
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Permanent link to this record |
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Author |
Van Aert, S.; De Backer, A.; Jones, L.; Martinez, G.T.; Béché, A.; Nellist, P.D. |
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Title |
Control of Knock-On Damage for 3D Atomic Scale Quantification of Nanostructures: Making Every Electron Count in Scanning Transmission Electron Microscopy |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Physical review letters |
Abbreviated Journal |
Phys Rev Lett |
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Volume |
122 |
Issue |
6 |
Pages |
066101 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Understanding nanostructures down to the atomic level is the key to optimizing the design of advancedmaterials with revolutionary novel properties. This requires characterization methods capable of quantifying the three-dimensional (3D) atomic structure with the highest possible precision. A successful approach to reach this goal is to count the number of atoms in each atomic column from 2D annular dark field scanning transmission electron microscopy images. To count atoms with single atom sensitivity, a minimum electron dose has been shown to be necessary, while on the other hand beam damage, induced by the high energy electrons, puts a limit on the tolerable dose. An important challenge is therefore to develop experimental strategies to optimize the electron dose by balancing atom-counting fidelity vs the risk of knock-on damage. To achieve this goal, a statistical framework combined with physics-based modeling of the dose-dependent processes is here proposed and experimentally verified. This model enables an investigator to theoretically predict, in advance of an experimental measurement, the optimal electron dose resulting in an unambiguous quantification of nanostructures in their native state with the highest attainable precision. |
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Wos |
000458824200008 |
Publication Date |
2019-02-13 |
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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 |
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ISSN |
0031-9007 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
8.462 |
Times cited |
3 |
Open Access |
OpenAccess |
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Notes |
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) through project fundings (WO.010.16N, G.0934.17N, G.0502.18N, G.0267.18N), and a grant to A. D. B. The research leading to these results has received funding from the European Union Seventh Framework Programme under Grant Agreement No. 312483— ESTEEM2 (Integrated Infrastructure Initiative-I3) and the UK EPSRC (Grant No. EP/M010708/1). |
Approved |
Most recent IF: 8.462 |
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Call Number |
EMAT @ emat @UA @ admin @ c:irua:157175 |
Serial |
5156 |
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Permanent link to this record |
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Author |
Jannis, D.; Müller-Caspary, K.; Béché, A.; Oelsner, A.; Verbeeck, J. |
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Title |
Spectroscopic coincidence experiments in transmission electron microscopy |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
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Volume |
114 |
Issue |
14 |
Pages |
143101 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
We demonstrate the feasibility of coincidence measurements on a conventional transmission electron microscope, revealing the temporal
correlation between electron energy loss spectroscopy (EELS) and energy dispersive X-ray (EDX) spectroscopy events. We make use of a
delay line detector with ps-range time resolution attached to a modified EELS spectrometer. We demonstrate that coincidence between both
events, related to the excitation and deexcitation of atoms in a crystal, provides added information not present in the individual EELS or
EDX spectra. In particular, the method provides EELS with a significantly suppressed or even removed background, overcoming the many
difficulties with conventional parametric background fitting as it uses no assumptions on the shape of the background, requires no user input
and does not suffer from counting noise originating from the background signal. This is highly attractive, especially when low concentrations
of elements need to be detected in a matrix of other elements. |
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Language |
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Wos |
000464450200022 |
Publication Date |
2019-04-08 |
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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 |
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ISSN |
0003-6951 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.411 |
Times cited |
18 |
Open Access |
OpenAccess |
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Notes |
Fonds Wetenschappelijk Onderzoek, G093417 ; Horizon 2020 Framework Programme, 823717 ESTEEM3 ; Helmholtz Association, VH-NG-1327 ; |
Approved |
Most recent IF: 3.411 |
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Call Number |
EMAT @ emat @UA @ admin @ c:irua:159155 |
Serial |
5168 |
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Permanent link to this record |
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Author |
Vanrompay, H.; Béché, A.; Verbeeck, J.; Bals, S. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
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Title |
Experimental Evaluation of Undersampling Schemes for Electron Tomography of Nanoparticles |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Particle and particle systems characterization |
Abbreviated Journal |
Part Part Syst Char |
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Volume |
36 |
Issue |
36 |
Pages |
1900096 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
One of the emerging challenges in the field of 3D characterization of nanoparticles by electron tomography is to avoid degradation and deformation of the samples during the acquisition of a tilt series. In order to reduce the required electron dose, various undersampling approaches have been proposed. These methods include lowering the number of 2D projection images, reducing the probe current during the acquisition, and scanning a smaller number of pixels in the 2D images. A comparison is made between these approaches based on tilt series acquired for a gold nanoparticle. |
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Language |
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Wos |
000477679400014 |
Publication Date |
2019-05-29 |
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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 |
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ISSN |
0934-0866 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.474 |
Times cited |
12 |
Open Access |
Not_Open_Access |
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Notes |
H.V. acknowledges financial support by the Research Foundation Flanders (FWO Grant No. 1S32617N). A.B. and J.V. acknowledge FWO project 6093417N “Compressed sensing enabling low dose imaging in STEM.” The authors thank G. González-Rubio, A. Sánchez-Iglesias, and L.M. Liz-Marzán for provision of the samples. |
Approved |
Most recent IF: 4.474 |
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Call Number |
EMAT @ emat @UA @ admin @ c:irua:159986 |
Serial |
5175 |
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Permanent link to this record |
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Author |
Guzzinati, G.; Ghielens, W.; Mahr, C.; Béché, A.; Rosenauer, A.; Calders, T.; Verbeeck, J. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
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Title |
Electron Bessel beam diffraction for precise and accurate nanoscale strain mapping |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
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Volume |
114 |
Issue |
24 |
Pages |
243501 |
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Keywords |
A1 Journal article; ADReM Data Lab (ADReM); Electron microscopy for materials research (EMAT) |
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Abstract |
Strain has a strong effect on the properties of materials and the performance of electronic devices. Their ever shrinking size translates into a constant demand for accurate and precise measurement methods with a very high spatial resolution. In this regard, transmission electron microscopes are key instruments thanks to their ability to map strain with a subnanometer resolution. Here, we present a method to measure strain at the nanometer scale based on the diffraction of electron Bessel beams. We demonstrate that our method offers a strain sensitivity better than 2.5 × 10−4 and an accuracy of 1.5 × 10−3, competing with, or outperforming, the best existing methods with a simple and easy to use experimental setup. |
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Corporate Author |
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Place of Publication |
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Editor ![sorted by Editor field, ascending order (up)](img/sort_asc.gif) |
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Language |
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Wos |
000472599100019 |
Publication Date |
2019-06-17 |
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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 |
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ISSN |
0003-6951 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.411 |
Times cited |
17 |
Open Access |
OpenAccess |
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Notes |
Deutsche Forschungsgemeinschaft, RO2057/12-2 ; Fonds Wetenschappelijk Onderzoek, G.0934.17N ; |
Approved |
Most recent IF: 3.411 |
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Call Number |
EMAT @ emat @UA @ admin @ c:irua:160119 |
Serial |
5181 |
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Permanent link to this record |
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Author |
Van den Broek, W.; Reed, B.W.; Béché, A.; Velazco, A.; Verbeeck, J.; Koch, C.T. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
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Title |
Various compressed sensing setups evaluated against Shannon sampling under constraint of constant illumination |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
IEEE transactions on computational imaging |
Abbreviated Journal |
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Volume |
5 |
Issue |
3 |
Pages |
502-514 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
Under the constraint of constant illumination, an information criterion is formulated for the Fisher information that compressed sensing measurements in optical and transmission electron microscopy contain about the underlying parameters. Since this approach requires prior knowledge of the signal's support in the sparse basis, we develop a heuristic quantity, the detective quantum efficiency (DQE), that tracks this information criterion well without this knowledge. In this paper, it is shown that for the investigated choice of sensing matrices, and in the absence of read-out noise, i.e., with only Poisson noise present, compressed sensing does not raise the amount of Fisher information in the recordings above that of Shannon sampling. Furthermore, enabled by the DQE's analytical tractability, the experimental designs are optimized by finding out the optimal fraction of on pixels as a function of dose and read-out noise. Finally, we introduce a regularization and demonstrate, through simulations and experiment, that it yields reconstructions attaining minimum mean squared error at experimental settings predicted by the DQE as optimal. |
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Corporate Author |
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Publisher |
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Place of Publication |
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Editor ![sorted by Editor field, ascending order (up)](img/sort_asc.gif) |
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Language |
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Wos |
000480352600013 |
Publication Date |
2019-01-24 |
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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 |
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ISSN |
2333-9403 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.546 |
Times cited |
7 |
Open Access |
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Notes |
; This work was supported by the Hercules fund from the Flemish Government (Qu-Ant-EM microscope used for the experimental data). The work of W. Van den Broek was supported by the DFG under Grant BR 5095/2-1 (Compressed sensing in ptychography and transmission electron microscopy). The work of A. Beche, A. Velazco, and J. Verbeeck was supported by the FWO under Grant G093417N (Compressed sensing enabling low dose imaging in transmission electron microscopy). The work of Christoph T. Koch was supported by the DFG under Grant CRC 951. The associate editor coordinating the review of this manuscript and approving it for publication was Dr. Chrysanthe Preza. ; |
Approved |
Most recent IF: NA |
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Call Number |
UA @ admin @ c:irua:161792 |
Serial |
5368 |
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Permanent link to this record |
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Author |
Idrissi, H.; Ghidelli, M.; Béché, A.; Turner, S.; Gravier, S.; Blandin, J.-J.; Raskin, J.-P.; Schryvers, D.; Pardoen, T. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
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Title |
Atomic-scale viscoplasticity mechanisms revealed in high ductility metallic glass films |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Scientific reports |
Abbreviated Journal |
Sci Rep-Uk |
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Volume |
9 |
Issue |
1 |
Pages |
13426 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
The fundamental plasticity mechanisms in thin freestanding Zr65Ni35 metallic glass films are investigated in order to unravel the origin of an outstanding strength/ductility balance. The deformation process is homogenous until fracture with no evidence of catastrophic shear banding. The creep/relaxation behaviour of the films was characterized by on-chip tensile testing, revealing an activation volume in the range 100–200 Å3. Advanced high-resolution transmission electron microscopy imaging and spectroscopy exhibit a very fine glassy nanostructure with well-defined dense Ni-rich clusters embedded in Zr-rich clusters of lower atomic density and a ~2–3 nm characteristic length scale. Nanobeam electron diffraction analysis reveals that the accumulation of plastic deformation at roomtemperature
correlates with monotonously increasing disruption of the local atomic order. These results provide experimental evidences of the dynamics of shear transformation zones activation in metallic glasses. The impact of the nanoscale structural heterogeneities on the mechanical properties including the rate dependent behaviour is discussed, shedding new light on the governing plasticity mechanisms in metallic glasses with initially heterogeneous atomic arrangement. |
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Place of Publication |
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Editor ![sorted by Editor field, ascending order (up)](img/sort_asc.gif) |
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Language |
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Wos |
000486139700008 |
Publication Date |
2019-09-17 |
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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 |
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ISSN |
2045-2322 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.259 |
Times cited |
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Open Access |
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Notes |
H. Idrissi is mandated by the Belgian National Fund for Scientific Research (FSR-FNRS). This work was supported by the FNRS under Grant PDR – T.0178.19. FWO project G093417N (‘Compressed sensing enabling low dose imaging in transmission electron microscopy’) and Hercules fund ‘Direct electron detector for soft matter TEM’ from Flemish Government are acknowledged. |
Approved |
Most recent IF: 4.259 |
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Call Number |
EMAT @ emat @c:irua:162786 |
Serial |
5375 |
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Permanent link to this record |
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Author |
Prabhakara, V.; Jannis, D.; Béché, A.; Bender, H.; Verbeeck, J. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
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Title |
Strain measurement in semiconductor FinFET devices using a novel moiré demodulation technique |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Semiconductor science and technology |
Abbreviated Journal |
Semicond Sci Tech |
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Volume |
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Issue |
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Pages |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
Moiré fringes are used throughout a wide variety of applications in physics and
engineering to bring out small variations in an underlying lattice by comparing with another reference lattice. This method was recently demonstrated in Scanning Transmission Electron Microscopy imaging to provide local strain measurement in crystals by comparing the crystal lattice with the scanning raster that then serves as the reference. The images obtained in this way contain a beating fringe pattern with a local period that represents the deviation of the lattice from the reference. In order to obtain the actual strain value, a region containing a full period of the fringe is required, which results in a compromise between strain sensitivity and spatial resolution. In this paper we propose an advanced setup making use of an optimised scanning pattern and a novel phase stepping demodulation scheme. We demonstrate the novel method on a series of 16 nm Si-Ge semiconductor FinFET devices in which strain plays a crucial role in modulating the charge carrier mobility. The obtained results are compared with both Nano-beam diffraction and the recently proposed Bessel beam diffraction technique. The setup provides a much improved spatial resolution over conventional moiré imaging in STEM while at the same time being fast and requiring no specialised diffraction camera as opposed to the diffraction techniques we compare to. |
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Corporate Author |
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Publisher |
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Place of Publication |
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Editor ![sorted by Editor field, ascending order (up)](img/sort_asc.gif) |
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Language |
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Wos |
000537721200002 |
Publication Date |
2019-11-29 |
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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 |
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ISSN |
0268-1242 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.305 |
Times cited |
8 |
Open Access |
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Notes |
The Qu-Ant-EM microscope and the direct electron detector used in the diffraction experiments was partly funded by the Hercules fund from the Flemish Government. This project has received funding from the GOA project “Solarpaint” of the University of Antwerp. We would also like to thank Dr. Thomas Nuytten and Prof. Dr. Wilfried Vandervorst from IMEC, Leuven for their continuous support and collaboration with the project. |
Approved |
Most recent IF: 2.305 |
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Call Number |
EMAT @ emat @c:irua:165794 |
Serial |
5445 |
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Permanent link to this record |