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Records |
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Author |
Lobato, I.; Van Aert, S.; Verbeeck, J. |
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Title |
Progress and new advances in simulating electron microscopy datasets using MULTEM |
Type |
A1 Journal article |
|
Year |
2016 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
|
Volume |
168 |
Issue |
168 |
Pages |
17-27 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
A new version of the open source program MULTEM is presented here. It includes a graphical user interface, tapering truncation of the atomic potential, CPU multithreading functionality, single/double precision calculations, scanning transmission electron microscopy (STEM) simulations using experimental detector sensitivities, imaging STEM (ISTEM) simulations, energy filtered transmission electron microscopy (EFTEM) simulations, STEM electron energy loss spectroscopy (EELS) simulations along with other improvements in the algorithms. We also present a mixed channeling approach for the calculation of inelastic excitations, which allows one to considerably speed up time consuming EFTEM/STEM-EELS calculations. |
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Address |
EMAT, University of Antwerp, Department of Physics, Groenenborgerlaan 171, B-2020 Antwerp, Belgium |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
English |
Wos |
000380754100003 |
Publication Date |
2016-06-11 |
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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 |
43 |
Open Access |
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|
Notes |
The 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. The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0374.13N, G.0369.15N and G.0368.15N).; esteem2jra3; esteem2na3; esteem2_jra2 |
Approved |
Most recent IF: 2.843 |
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Call Number |
c:irua:134088 c:irua:134088UA @ admin @ c:irua:134088 |
Serial |
4093 |
Permanent link to this record |
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Author |
Alania, M.; Altantzis, T.; De Backer, A.; Lobato, I.; Bals, S.; Van Aert, S. |
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Title |
Depth sectioning combined with atom-counting in HAADF STEM to retrieve the 3D atomic structure |
Type |
A1 Journal article |
|
Year |
2016 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
|
Volume |
177 |
Issue |
177 |
Pages |
36-42 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Aberration correction in scanning transmission electron microscopy (STEM) has greatly improved the lateral and depth resolution. When using depth sectioning, a technique during which a series of images is recorded at different defocus values, single impurity atoms can be visualised in three dimensions. In this paper, we investigate new possibilities emerging when combining depth sectioning and precise atom-counting in order to reconstruct nanosized particles in three dimensions. Although the depth resolution does not allow one to precisely locate each atom within an atomic column, it will be shown that the depth location of an atomic column as a whole can be measured precisely. In this manner, the morphology of a nanoparticle can be reconstructed in three dimensions. This will be demonstrated using simulations and experimental data of a gold nanorod. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000401219800006 |
Publication Date |
2016-11-09 |
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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 |
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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 |
13 |
Open Access |
OpenAccess |
|
Notes |
The 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. S. Bals acknowledges funding from the European Research Council (Starting Grant No. COLOURATOMS 335078). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0374.13N, G.0369.15N and G.0368.15N) and a post-doctoral grant to A. De Backer and T. Altantzis. The authors are grateful to Professor Luis M. Liz-Marzán for providing the sample.; ECAS_Sara; (ROMEO:green; preprint:; postprint:can ; pdfversion:cannot); |
Approved |
Most recent IF: 2.843 |
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Call Number |
EMAT @ emat @ c:irua:138015UA @ admin @ c:irua:138015 |
Serial |
4316 |
Permanent link to this record |
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Author |
Alania, M.; De Backer, A.; Lobato, I.; Krause, F.F.; Van Dyck, D.; Rosenauer, A.; Van Aert, S. |
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Title |
How precise can atoms of a nanocluster be located in 3D using a tilt series of scanning transmission electron microscopy images? |
Type |
A1 Journal article |
|
Year |
2017 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
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Volume |
181 |
Issue |
181 |
Pages |
134-143 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
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Abstract |
In this paper, we investigate how precise atoms of a small nanocluster can ultimately be located in three dimensions (3D) from a tilt series of images acquired using annular dark field (ADF) scanning transmission electron microscopy (STEM). Therefore, we derive an expression for the statistical precision with which the 3D atomic position coordinates can be estimated in a quantitative analysis. Evaluating this statistical precision as a function of the microscope settings also allows us to derive the optimal experimental design. In this manner, the optimal angular tilt range, required electron dose, optimal detector angles, and number of projection images can be determined. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000411170800016 |
Publication Date |
2016-12-15 |
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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 |
3 |
Open Access |
OpenAccess |
|
Notes |
The 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. The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0374.13N, G.0369.15N, G.0368.15N, and WO.010.16N) and a post-doctoral grant to A. De Backer, and from the DFG under contract No. RO-2057/4-2. |
Approved |
Most recent IF: 2.843 |
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Call Number |
EMAT @ emat @ c:irua:144432 |
Serial |
4618 |
Permanent link to this record |
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Author |
Schryvers, D.; Salje, E.K.H.; Nishida, M.; De Backer, A.; Idrissi, H.; Van Aert, S. |
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Title |
Quantification by aberration corrected (S)TEM of boundaries formed by symmetry breaking phase transformations |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
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Volume |
176 |
Issue |
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Pages |
194-199 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The present contribution gives a review of recent quantification work of atom displacements, atom site occupations and level of crystallinity in various systems and based on aberration corrected HR(S)TEM images. Depending on the case studied, picometer range precisions for individual distances can be obtained, boundary widths at the unit cell level determined or statistical evolutions of fractions of the ordered areas calculated. In all of these cases, these quantitative measures imply new routes for the applications of the respective materials. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000403992200026 |
Publication Date |
2017-01-09 |
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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 |
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 |
1 |
Open Access |
OpenAccess |
|
Notes |
The authors acknowledge financial support from the Fund for Scientific Research-Flanders (G.0064.10N, G.0393.11N, G.0374.13N, G.0368.15N, G.0369.15N) and the Flemish Hercules 3 program for large infrastructure as well as financial support from the European Union Seventh Framework Programme (FP7/2007 – 2013) under Grant agreement no. 312483 (ESTEEM2). EKHS thanks EPSRC (EP/ K009702/1) and the Leverhulme trust (EM-2016-004) for support. DS and MN acknowledge financial support from the Japan Society for the Promotion of Science (JSPS, Japan) through the Grant-in-Aid for Scientific Research (A: No. 26249090) and the Strategic Young Researcher Overseas Visits Program for Accelerating Brain Circulation (R2408). |
Approved |
Most recent IF: 2.843 |
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Call Number |
EMAT @ emat @c:irua:149654 |
Serial |
4914 |
Permanent link to this record |
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Author |
van Aarle, W.; Palenstijn, W.J.; De Beenhouwer, J.; Altantzis, T.; Bals, S.; Batenburg, K.J.; Sijbers, J. |
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Title |
The ASTRA Toolbox: A platform for advanced algorithm development in electron tomography |
Type |
A1 Journal article |
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Year |
2015 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
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Volume |
157 |
Issue |
157 |
Pages |
35-47 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
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Abstract |
We present the ASTRA Toolbox as an open platform for 3D image reconstruction in tomography. Most of the software tools that are currently used in electron tomography offer limited flexibility with respect to the geometrical parameters of the acquisition model and the algorithms used for reconstruction. The ASTRA Toolbox provides an extensive set of fast and flexible building blocks that can be used to develop advanced reconstruction algorithms, effectively removing these limitations. We demonstrate this flexibility, the resulting reconstruction quality, and the computational efficiency of this toolbox by a series of experiments, based on experimental dual-axis tilt series. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
English |
Wos |
000361002400005 |
Publication Date |
2015-05-06 |
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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 |
562 |
Open Access |
OpenAccess |
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Notes |
The authors acknowledge financial support from the iMinds ICONMetroCT project,the IWT SBO Tom Food project and from the Netherlands Organisation for Scientific Research (NWO),Project no. 639.072.005. Networking support was provided by the EXTREMA COST Action MP 1207. Sara Bals acknowledges financial support from the European Research Council (ERC Starting Grant #335078 COLOURATOMS).; ECAS_Sara; (ROMEO:green; preprint:; postprint:can ; pdfversion:cannot); |
Approved |
Most recent IF: 2.843; 2015 IF: 2.436 |
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Call Number |
c:irua:127834 |
Serial |
3974 |
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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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
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 |
Permanent link to this record |
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Author |
Martinez, G.T.; van den Bos, K.H.W.; Alania, M.; Nellist, P.D.; Van Aert, S. |
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Title |
Thickness dependence of scattering cross-sections in quantitative scanning transmission electron microscopy |
Type |
A1 Journal article |
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Year |
2018 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
|
Volume |
187 |
Issue |
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Pages |
84-92 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
In quantitative scanning transmission electron microscopy (STEM), scattering cross-sections have been shown to be very sensitive to the number of atoms in a column and its composition. They correspond to the integrated intensity over the atomic column and they outperform other measures. As compared to atomic column peak intensities, which saturate at a given thickness, scattering cross-sections increase monotonically. A study of the electron wave propagation is presented to explain the sensitivity of the scattering cross-sections. Based on the multislice algorithm, we analyse the wave propagation inside the crystal and its link to the scattered signal for the different probe positions contained in the scattering cross-section for detector collection in the low-, middle- and high-angle regimes. The influence to the signal from scattering of neighbouring columns is also discussed. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000428131200011 |
Publication Date |
2018-01-31 |
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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 |
|
Impact Factor |
2.843 |
Times cited |
4 |
Open Access |
Not_Open_Access: Available from 01.02.2020
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|
Notes |
The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings ( G.0374.13N , G.0369.15N , G.0368.15N and WO.010.16N ) and a PhD grant to K.H.W.v.d.B. The research leading to these results has received funding from the European Union 7th Framework Programme [ FP7 /2007-2013] under Grant agreement no. 312483 (ESTEEM2). The authors are grateful to A. Rosenauer for providing access to the StemSim software. |
Approved |
Most recent IF: 2.843 |
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Call Number |
EMAT @ emat @c:irua:149384 |
Serial |
4809 |
Permanent link to this record |
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Author |
Gonnissen, J.; De Backer, A.; den Dekker, A.J.; Sijbers, J.; Van Aert, S. |
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Title |
Detecting and locating light atoms from high-resolution STEM images: The quest for a single optimal design |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
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Volume |
170 |
Issue |
170 |
Pages |
128-138 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
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Abstract |
In the present paper, the optimal detector design is investigated for both detecting and locating light atoms from high resolution scanning transmission electron microscopy (HR STEM) images. The principles of detection theory are used to quantify the probability of error for the detection of light atoms from HR STEM images. To determine the optimal experiment design for locating light atoms, use is made of the so-called Cramer-Rao Lower Bound (CRLB). It is investigated if a single optimal design can be found for both the detection and location problem of light atoms. Furthermore, the incoming electron dose is optimised for both research goals and it is shown that picometre range precision is feasible for the estimation of the atom positions when using an appropriate incoming electron dose under the optimal detector settings to detect light atoms. |
|
Address |
Electron Microscopy for Materials Science (EMAT), University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium. Electronic address: sandra.vanaert@uantwerpen.be |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
English |
Wos |
000386925500014 |
Publication Date |
2016-07-26 |
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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 |
6 |
Open Access |
|
|
Notes |
The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0368.15, G.0369.15 and G.0374.13) and a postdoctoral research grant to A. De Backer. The research leading to these results has also received funding from the European Union Seventh Framework Programme [FP7/2007-2013] under Grant agreement no. 312483 (ESTEEM2). The authors would also like to thank A. Rosenauer for providing access to the STEMsim software and Gerardo T. Martinez for fruitful discussions.; esteem2_jra2 |
Approved |
Most recent IF: 2.843 |
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Call Number |
c:irua:135337 c:irua:135337 |
Serial |
4128 |
Permanent link to this record |
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Author |
van den Bos, K.H.W.; Janssens, L.; De Backer, A.; Nellist, P.D.; Van Aert, S. |
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Title |
The atomic lensing model: new opportunities for atom-by-atom metrology of heterogeneous nanomaterials |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
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Volume |
203 |
Issue |
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Pages |
155 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The atomic lensing model has been proposed as a promising method facilitating atom-counting in heterogeneous nanocrystals [1]. Here, image simulations will validate the model, which describes dynamical diffraction as a superposition of individual atoms focussing the incident electrons. It will be demonstrated that the model is reliable in the annular dark field regime for crystals having columns containing dozens of atoms. By using the principles of statistical detection theory, it will be shown that this model gives new opportunities for detecting compositional differences. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000465021000020 |
Publication Date |
2018-12-06 |
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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 |
4 |
Open Access |
OpenAccess |
|
Notes |
The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0369.15N, G.0502.18N and WO.010.16N), and by personal grants to K.H.W. van den Bos and A. De Backer. This project has received funding from the European Research Council (ERC) under the European Unions Horizon 2020 research and innovation programme (grant agreement No. 770887). |
Approved |
Most recent IF: 2.843 |
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Call Number |
EMAT @ emat @UA @ admin @ c:irua:155721 |
Serial |
5074 |
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 |
|
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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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
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 |
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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 |
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 |
Permanent link to this record |
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Author |
De wael, A.; De Backer, A.; Jones, L.; Nellist, P.D.; Van Aert, S. |
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Title |
Hybrid statistics-simulations based method for atom-counting from ADF STEM images |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
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Volume |
177 |
Issue |
177 |
Pages |
69-77 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
A hybrid statistics-simulations based method for atom-counting from annular dark field scanning transmission electron microscopy (ADF STEM) images of monotype crystalline nanostructures is presented. Different atom-counting methods already exist for model-like systems. However, the increasing relevance of radiation damage in the study of nanostructures demands a method that allows atom-counting from low dose images with a low signal-to-noise ratio. Therefore, the hybrid method directly includes prior knowledge from image simulations into the existing statistics-based method for atom-counting, and accounts in this manner for possible discrepancies between actual and simulated experimental conditions. It is shown by means of simulations and experiments that this hybrid method outperforms the statistics-based method, especially for low electron doses and small nanoparticles. The analysis of a simulated low dose image of a small nanoparticle suggests that this method allows for far more reliable quantitative analysis of beam-sensitive materials. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000401219800010 |
Publication Date |
2017-01-25 |
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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 |
|
|
ISSN |
0304-3991 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
2.843 |
Times cited |
8 |
Open Access |
OpenAccess |
|
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 WO.010.16N), and a postdoctoral 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). The authors are grateful to G.T. Martinez for providing image simulations. |
Approved |
Most recent IF: 2.843 |
|
Call Number |
EMAT @ emat @ c:irua:141718 |
Serial |
4486 |
Permanent link to this record |
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Author |
De Backer, A.; van den Bos, K.H.W.; Van den Broek, W.; Sijbers, J.; Van Aert, S. |
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Title |
StatSTEM: An efficient approach for accurate and precise model-based quantification of atomic resolution electron microscopy images |
Type |
A1 Journal article |
|
Year |
2016 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
|
Volume |
171 |
Issue |
171 |
Pages |
104-116 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
|
Abstract |
An efficient model-based estimation algorithm is introduced to quantify the atomic column positions and intensities from atomic resolution (scanning) transmission electron microscopy ((S)TEM) images. This algorithm uses the least squares estimator on image segments containing individual columns fully accounting for overlap between neighbouring columns, enabling the analysis of a large field of view. For this algorithm, the accuracy and precision with which measurements for the atomic column positions and scattering cross-sections from annular dark field (ADF) STEM images can be estimated, has been investigated. The highest attainable precision is reached even for low dose images. Furthermore, the advantages of the model-based approach taking into account overlap between neighbouring columns are highlighted. This is done for the estimation of the distance between two neighbouring columns as a function of their distance and for the estimation of the scattering cross-section which is compared to the integrated intensity from a Voronoi cell. To provide end-users this well-established quantification method, a user friendly program, StatSTEM, is developed which is freely available under a GNU public license. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000389106200014 |
Publication Date |
2016-09-09 |
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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 |
|
Impact Factor |
2.843 |
Times cited |
43 |
Open Access |
|
|
Notes |
The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0393.11, G.0064.10 and G.0374.13), a Ph.D. research grant to K.H.W. van den Bos, and a postdoctoral 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). A. Rosenauer is acknowledged for providing the STEMsim program.; esteem2_jra2 |
Approved |
Most recent IF: 2.843 |
|
Call Number |
EMAT @ emat @ c:irua:135516 |
Serial |
4280 |
Permanent link to this record |
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Author |
Fatermans, J.; Van Aert, S.; den Dekker, A.J. |
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Title |
The maximum a posteriori probability rule for atom column detection from HAADF STEM images |
Type |
A1 Journal article |
|
Year |
2019 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
|
Volume |
201 |
Issue |
|
Pages |
81-91 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
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Abstract |
Recently, the maximum a posteriori (MAP) probability rule has been proposed as an objective and quantitative method to detect atom columns and even single atoms from high-resolution high-angle annular dark-field (HAADF) scanning transmission electron microscopy (STEM) images. The method combines statistical parameter estimation and model-order selection using a Bayesian framework and has been shown to be especially useful for the analysis of the structure of beam-sensitive nanomaterials. In order to avoid beam damage, images of such materials are usually acquired using a limited incoming electron dose resulting in a low contrast-to-noise ratio (CNR) which makes visual inspection unreliable. This creates a need for an objective and quantitative approach. The present paper describes the methodology of the MAP probability rule, gives its step-by-step derivation and discusses its algorithmic implementation for atom column detection. In addition, simulation results are presented showing that the performance of the MAP probability rule to detect the correct number of atomic columns from HAADF STEM images is superior to that of other model-order selection criteria, including the Akaike Information Criterion (AIC) and the Bayesian Information Criterion (BIC). Moreover, the MAP probability rule is used as a tool to evaluate the relation between STEM image quality measures and atom detectability resulting in the introduction of the so-called integrated CNR (ICNR) as a new image quality measure that better correlates with atom detectability than conventional measures such as signal-to-noise ratio (SNR) and CNR. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000466343800009 |
Publication Date |
2019-02-04 |
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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 |
|
Impact Factor |
2.843 |
Times cited |
1 |
Open Access |
OpenAccess |
|
Notes |
The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (No. W.O.010.16N, No. G.0368.15N, No. G.0502.18N). This project has received funding from the European Research Council (ERC) under the European Unions Horizon 2020 research and innovation programme (Grant Agreement No. 770887). |
Approved |
Most recent IF: 2.843 |
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Call Number |
EMAT @ emat @UA @ admin @ c:irua:157176 |
Serial |
5153 |
Permanent link to this record |
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Author |
Fatermans, J.; den Dekker, Aj.; Müller-Caspary, K.; Gauquelin, N.; Verbeeck, J.; Van Aert, S. |
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Title |
Atom column detection from simultaneously acquired ABF and ADF STEM images |
Type |
A1 Journal article |
|
Year |
2020 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
|
Volume |
219 |
Issue |
|
Pages |
113046 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
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Abstract |
In electron microscopy, the maximum a posteriori (MAP) probability rule has been introduced as a tool to determine the most probable atomic structure from high-resolution annular dark-field (ADF) scanning transmission electron microscopy (STEM) images exhibiting low contrast-to-noise ratio (CNR). Besides ADF imaging, STEM can also be applied in the annular bright-field (ABF) regime. The ABF STEM mode allows to directly visualize light-element atomic columns in the presence of heavy columns. Typically, light-element nanomaterials are sensitive to the electron beam, limiting the incoming electron dose in order to avoid beam damage and leading to images exhibiting low CNR. Therefore, it is of interest to apply the MAP probability rule not only to ADF STEM images, but to ABF STEM images as well. In this work, the methodology of the MAP rule, which combines statistical parameter estimation theory and model-order selection, is extended to be applied to simultaneously acquired ABF and ADF STEM images. For this, an extension of the commonly used parametric models in STEM is proposed. Hereby, the effect of specimen tilt has been taken into account, since small tilts from the crystal zone axis affect, especially, ABF STEM intensities. Using simulations as well as experimental data, it is shown that the proposed methodology can be successfully used to detect light elements in the presence of heavy elements. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000594768500005 |
Publication Date |
2020-06-01 |
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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 |
|
Impact Factor |
2.2 |
Times cited |
9 |
Open Access |
OpenAccess |
|
Notes |
The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (No. W.O.010.16N, No. G.0368.15N, No. G.0502.18N, EOS 30489208). 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 funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 823717 – ESTEEM3. The direct electron detector (Medipix3, Quantum Detectors) was funded by the Hercules fund from the Flemish Government. K. M. C. acknowledges funding from the Initiative and Network Fund of the Helmholtz Association (Germany) under contract VH-NG-1317. The authors thank Mark Huijben from the University of Twente (Enschede, The Netherlands) for providing the LiMn2O4 sample used in section 4.2 of this study. N. G., J. V., and S. V. A. acknowledge funding from the University of Antwerp through the Concerted Research Actions (GOA) project Solarpaint and the TOP project. |
Approved |
Most recent IF: 2.2; 2020 IF: 2.843 |
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Call Number |
EMAT @ emat @c:irua:169706 |
Serial |
6373 |
Permanent link to this record |
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Author |
Fatermans, J.; den Dekker, A. J.; Müller-Caspary, K.; Lobato, I.; O’Leary, C. M.; Nellist, P. D.; Van Aert, S. |
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Title |
Single Atom Detection from Low Contrast-to-Noise Ratio Electron Microscopy Images |
Type |
A1 Journal article |
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Year |
2018 |
Publication |
Physical review letters |
Abbreviated Journal |
Phys Rev Lett |
|
Volume |
121 |
Issue |
5 |
Pages |
056101 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
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Abstract |
Single atom detection is of key importance to solving a wide range of scientific and technological problems. The strong interaction of electrons with matter makes transmission electron microscopy one of the most promising techniques. In particular, aberration correction using scanning transmission electron microscopy has made a significant step forward toward detecting single atoms. However, to overcome radiation damage, related to the use of high-energy electrons, the incoming electron dose should be kept low enough. This results in images exhibiting a low signal-to-noise ratio and extremely weak contrast, especially for light-element nanomaterials. To overcome this problem, a combination of physics-based model fitting and the use of a model-order selection method is proposed, enabling one to detect single atoms with high reliability. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000440143200007 |
Publication Date |
2018-07-30 |
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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 |
|
Impact Factor |
8.462 |
Times cited |
6 |
Open Access |
OpenAccess |
|
Notes |
The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through Project fundings (No. WO.010.16N, No. G.0368.15N, No. G.0502.18N). The authors are grateful to M. Van Bael and P. Lievens (KU Leuven) and to L. M. Liz-Marzán (CIC biomaGUNE and Ikerbasque) for providing the samples. This project has received funding from the European Research Council (ERC) under the European Unions Horizon 2020 research and innovation programme (Grant Agreement No. 770887). |
Approved |
Most recent IF: 8.462 |
|
Call Number |
EMAT @ emat @c:irua:152819 |
Serial |
5004 |
Permanent link to this record |
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Author |
van den Bos, K.H. W.; De Backer, A.; Martinez, G.T.; Winckelmans, N.; Bals, S.; Nellist, P.D.; Van Aert, S. |
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Title |
Unscrambling Mixed Elements using High Angle Annular Dark Field Scanning Transmission Electron Microscopy |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Physical review letters |
Abbreviated Journal |
Phys Rev Lett |
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Volume |
116 |
Issue |
116 |
Pages |
246101 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The development of new nanocrystals with outstanding physicochemical properties requires a full threedimensional (3D) characterization at the atomic scale. For homogeneous nanocrystals, counting the number of atoms in each atomic column from high angle annular dark field scanning transmission electron microscopy images has been shown to be a successful technique to get access to this 3D information. However, technologically important nanostructures often consist of more than one chemical element. In order to extend atom counting to heterogeneous materials, a new atomic lensing model is presented. This model takes dynamical electron diffraction into account and opens up new possibilities for unraveling the 3D composition at the atomic scale. Here, the method is applied to determine the 3D structure of Au@Ag core-shell nanorods, but it is applicable to a wide range of heterogeneous complex nanostructures. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000378059500010 |
Publication Date |
2016-06-17 |
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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 |
0031-9007 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
8.462 |
Times cited |
46 |
Open Access |
OpenAccess |
|
Notes |
The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through Projects No. G.0374.13N, No. G.0368.15N, and No. G.0369.15N, and by grants to K. H.W. van den Bos and A. De Backer. S. Bals and N. Winckelmans acknowledge funding from the European Research Council (Starting Grant No. COLOURATOMS 335078). The research leading to these results has received funding from the European Union Seventh Framework Programme under Grant No. 312483—ESTEEM2. The authors are grateful to A. Rosenauer for providing the STEMsim program.; esteem2jra2; ECASSara; (ROMEO:green; preprint:; postprint:can ; pdfversion:can); |
Approved |
Most recent IF: 8.462 |
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Call Number |
c:irua:133954 c:irua:133954 |
Serial |
4084 |
Permanent link to this record |
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Author |
Cremers, V.; Rampelberg, G.; Barhoum, A.; Walters, P.; Claes, N.; Oliveira, T.M. de; Assche, G.V.; Bals, S.; Dendooven, J.; Detavernier, C. |
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Title |
Oxidation barrier of Cu and Fe powder by Atomic Layer Deposition |
Type |
A1 Journal article |
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Year |
2018 |
Publication |
Surface and coatings technology |
Abbreviated Journal |
Surf Coat Tech |
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Volume |
349 |
Issue |
349 |
Pages |
1032-1041 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Atomic layer deposition (ALD) is a vapor based technique which allows to deposit uniform, conformal films with a thickness control at the atomic scale. In this research, Al 2 O 3 coatings were deposited on micrometer-sized Fe and Cu powder (particles) using the thermal trimethylaluminum (TMA)/ water (H 2 O) process in a rotary pump-type ALD reactor. Rotation of the powder during deposition was required to obtain a pinhole-free ALD coating. The protective nature of the coating was evaluated by quantifying its effectiveness in protecting the metal particles during oxidative annealing treatments. The Al 2 O 3 coated powders were annealed in ambient air while in-situ thermogravimetric analysis (TGA) and in-situ x-ray diffraction (XRD) data were acquired. The thermal stability of a series of Cu and Fe powder with different Al 2 O 3 thicknesses were determined with TGA. In both samples a clear shift in oxidation temperature is visible. For Cu and Fe powder coated with 25 nm Al 2 O 3 , we observed an increase of the oxidation temperature with 300-400°C. For the Cu powder a thin film of only 8 nm is required to obtain an initial increase in oxidation temperature of 200°C. In contrast, for Fe powder a thicker coating of 25 nm is required. In both cases, the oxidation temperature increases with increasing thickness of the Al 2 O 3 coating. These results illustrate that the Al 2 O 3 thin film, deposited by the thermal ALD process (TMA/H 2 O) can be an efficient and pinhole-free barrier layer for micrometer-sized powder particles, provided that the powder is properly agitated during the process to ensure sufficient vapour-solid interaction. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000441492600108 |
Publication Date |
2018-06-25 |
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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 |
0257-8972 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
2.589 |
Times cited |
10 |
Open Access |
OpenAccess |
|
Notes |
The authors acknowledge financial support from the Strategic Initiative Materials in Flanders (SIM, SBO-FUNC project) and the Special Research Fund BOF of Ghent University (GOA 01G01513). J. D. acknowledges the Research Foundation Flanders (FWO-Vlaanderen) for a postdoctoral fellowship. N.C. and S.B. acknowledge financial support from European Research Council (ERC Starting Grant 335078-COLOURATOMS). The authors acknowledge S. Goeteyn for the assistance in preliminary depositions. (ROMEO:green; preprint:; postprint:can ; pdfversion:cannot); ecas_sara |
Approved |
Most recent IF: 2.589 |
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Call Number |
EMAT @ emat @c:irua:152174UA @ admin @ c:irua:152174 |
Serial |
4994 |
Permanent link to this record |
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Author |
Cremers, V.; Rampelberg, G.; Baert, K.; Abrahami, S.; Claes, N.; de Oliveira, T.M.; Terryn, H.; Bals, S.; Dendooven, J.; Detavernier, C. |
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Title |
Corrosion protection of Cu by atomic layer deposition |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Journal of vacuum science and technology: A: vacuum surfaces and films |
Abbreviated Journal |
J Vac Sci Technol A |
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Volume |
37 |
Issue |
37 |
Pages |
060902 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Atomic layer deposition (ALD) is a vapor phase technique that is able to deposit uniform, conformal thin films with an excellent thickness control at the atomic scale. 18 nm thick Al2O3 and TiO2 coatings were deposited conformaly and pinhole-free onto micrometer-sized Cu powder, using trimethylaluminum and tetrakis(dimethylamido)titanium(IV), respectively, as a precursor and de-ionized water as a reactant. The capability of the ALD coating to protect the Cu powder against corrosion was investigated. Therefore, the stability of the coatings was studied in solutions with different pH in the range of 0–14, and in situ raman spectroscopy was used to detect the emergence of corrosion products of Cu as an indication that the protective coating starts to fail. Both ALD coatings provide good protection at standard pH values in the range of 5–7. In general, the TiO2 coating shows a better barrier protection against corrosion than the Al2O3 coating. However, for the most extreme pH conditions, pH 0 and pH 14, the TiO2 coating starts also to degrade. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000517925800003 |
Publication Date |
2019-09-19 |
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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 |
0734-2101 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
1.374 |
Times cited |
7 |
Open Access |
OpenAccess |
|
Notes |
The authors acknowledge financial support from the Strategic Initiative Materials in Flanders (SIM, SBO-FUNC project) and the Special Research Fund BOF of Ghent University (No. GOA 01G01513). J.D. acknowledges the Research Foundation Flanders (FWO-Vlaanderen) for a postdoctoral fellowship. |
Approved |
Most recent IF: 1.374 |
|
Call Number |
EMAT @ emat @c:irua:162640 |
Serial |
5361 |
Permanent link to this record |
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Author |
Degutis, G.; Pobedinskas, P.; Turner, S.; Lu, Y.-G.; Al Riyami, S.; Ruttens, B.; Yoshitake, T.; D'Haen, J.; Haenen, K.; Verbeeck, J.; Hardy, A.; Van Bael, M.K. |
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Title |
CVD diamond growth from nanodiamond seeds buried under a thin chromium layer |
Type |
A1 Journal article |
|
Year |
2016 |
Publication |
Diamond and related materials |
Abbreviated Journal |
Diam Relat Mater |
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Volume |
64 |
Issue |
64 |
Pages |
163-168 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
This work presents a morphological and structural analysis of CVD diamond growth on silicon from nanodiamond seeds covered by a 50 nm thick chromium layer. The role of carbon diffusion as well as chromium and carbon silicide formation is analyzed. The local diamond environment is investigated by scanning transmission electron microscopy in combination with electron energy-loss spectroscopy. The evolution of the diamond phase composition (sp3/sp2) is evaluated by micro-Raman spectroscopy. Raman and X-ray diffraction analysis are used to identify the interfacial phases formed during CVD growth. Based upon the observed morphological and structural evolution, a diamond growth model from nanodiamond seeds buried beneath a thin Cr layer is proposed. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000374608100020 |
Publication Date |
2016-02-20 |
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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 |
0925-9635 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.561 |
Times cited |
11 |
Open Access |
|
|
Notes |
The authors acknowledge financial support provided by Research Program FWO G.056.810 and G0044.13N. A.H. and M.K.V.B are grateful to Hercules Foundation Flanders for financial support. P.P. and S.T. are Postdoctoral Fellows of the Research Foundation – Flanders (FWO). The Titan microscope used for this work was partially funded by the Hercules Foundation. |
Approved |
Most recent IF: 2.561 |
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Call Number |
c:irua:133624UA @ admin @ c:irua:133624 |
Serial |
4091 |
Permanent link to this record |
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Author |
Peters, J.L.; Altantzis, T.; Lobato, I.; Jazi, M.A.; van Overbeek, C.; Bals, S.; Vanmaekelbergh, D.; Sinai, S.B. |
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Title |
Mono- and Multilayer Silicene-Type Honeycomb Lattices by Oriented Attachment of PbSe Nanocrystals: Synthesis, Structural Characterization, and Analysis of the Disorder |
Type |
A1 Journal article |
|
Year |
2018 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
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Volume |
30 |
Issue |
30 |
Pages |
4831-4837 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Nanocrystal (NC) solids are commonly prepared from nonpolar organic NC suspensions. In many cases, the capping on the NC surface is preserved and forms a barrier between the NCs. More recently, superstructures with crystalline connections between the NCs, implying the removal of the capping, have been reported, too. Here, we present large-scale uniform superstructures of attached PbSe NCs with a silicene-type honeycomb geometry, resulting from solvent evaporation under nearly reversible conditions. We also prepared multilayered silicene honeycomb structures by using larger amounts of PbSe NCs. We show that the two-dimensional silicene superstructures can be seen as a crystallographic slice from a 3-D simple cubic structure. We describe the disorder in the silicene lattices in terms of the nanocrystals position and their atomic alignment. The silicene honeycomb sheets are large enough to be used in transistors and optoelectronic devices. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000440105500042 |
Publication Date |
2018-07-24 |
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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 |
|
|
ISSN |
0897-4756 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
9.466 |
Times cited |
33 |
Open Access |
OpenAccess |
|
Notes |
The authors acknowledge funding from the European Commission (Grant EUSMI 731019). S.B. acknowledges funding from the European Research Council (Grant 335078 COLOURATOM). T.A. acknowledges a postdoctoral grant from the Research Foundation Flanders (FWO). The authors acknowledge financial support from the European Commission under the Horizon 2020 Programme by means of the Grant Agreement No. 731019 EUSMI. (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); ecas_sara |
Approved |
Most recent IF: 9.466 |
|
Call Number |
EMAT @ emat @c:irua:152997UA @ admin @ c:irua:152997 |
Serial |
5011 |
Permanent link to this record |
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|
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Author |
Albrecht, W.; Van Aert, S.; Bals, S. |
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Title |
Three-Dimensional Nanoparticle Transformations Captured by an Electron Microscope |
Type |
A1 Journal article |
|
Year |
2021 |
Publication |
Accounts Of Chemical Research |
Abbreviated Journal |
Accounts Chem Res |
|
Volume |
54 |
Issue |
5 |
Pages |
1189-1199 |
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000626269900011 |
Publication Date |
2021-03-02 |
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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 |
0001-4842 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
20.268 |
Times cited |
12 |
Open Access |
OpenAccess |
|
Notes |
The authors acknowledge funding from the European Research Council under the European Union’s Horizon 2020 research and innovation program (ERC Consolidator Grants No. 815128–REALNANO and No. 770887–PICOMETRICS), the Research Foundation Flanders (FWO, G.0267.18N), and the European Commission (EUSMI). The authors furthermore acknowledge funding from the European Union’s Horizon 2020 research and innovation program, ESTEEM3. The authors also acknowledge contributions from all co-workers that have contributed over the years: Thomas Altantzis, Annick De Backer, Joost Batenburg and co-workers, Armand Béché, Eva Bladt, Lewys Jones and co-workers, Luis Liz-Marzán and co-workers, Ivan Lobato, Thais Milagres de Oliveira, Peter Nellist and co-workers, Hugo Pérez Garza and co-workers, Alexander Skorikov, Sara Skrabalak and co-workers, Sandra Van Aert, Alfons van Blaaderen and co-workers, Hans Vanrompay, Staf Van Tendeloo, and Johan Verbeeck.; sygmaSB; |
Approved |
Most recent IF: 20.268 |
|
Call Number |
EMAT @ emat @c:irua:177644 |
Serial |
6752 |
Permanent link to this record |
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Author |
Yuan, R.; Claes, N.; Verheyen, E.; Tuel, A.; Bals, S.; Breynaert, E.; Martens, J.; Kirschhock, C.E.A. |
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Title |
Synthesis of IWW-type germanosilicate zeolite using 5-azonia-spiro[4, 4]nonane as structure directing agent |
Type |
A1 Journal article |
|
Year |
2016 |
Publication |
New journal of chemistry |
Abbreviated Journal |
New J Chem |
|
Volume |
40 |
Issue |
40 |
Pages |
4319-4324 |
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
Abstract |
IWW-type zeolite with Si/Ge of 4.9 is obtained using 5-azonia-spiro[4,4]nonane as template in fluoride-free medium under hydrothermal conditions at 175 °C. In an otherwise identical synthesis, using the related 5-azonia-spiro[4,5]decane as structure directing agent, a mixture of IWW and NON zeolite types was formed. In absence of GeO2 from the reactant mixture, pure NON formed. The IWW zeolite was characterized by XRD, SEM, and HRTEM. IWW zeolite displayed a unique morphology and could be calcined at 600 °C without loss of crystallinity. The Si/Ge ratio of the IWW zeolite was increased by postsynthesis modification. Part of the germanium could be eliminated from the as-synthesized IWW zeolite by acid leaching using 6 M HCl solution. Also the calcined material could be degermanated. Here the presence of a silicon source in the acidic leaching solution minimized structural damage. This way the Si/Ge ratio of the IWW zeolite was increased from 4.9 up to 10. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000375586400038 |
Publication Date |
2016-02-19 |
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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 |
1144-0546 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
3.269 |
Times cited |
8 |
Open Access |
OpenAccess |
|
Notes |
The authors acknowledge FWO/NWO and ESRF for providing beam time at the DUBBLE and SNBL beamlines (ESRF, Grenoble) and P. Abdala for her assistance during the use of the beamline. The authors are grateful to L. Van Tendeloo for taking SEM images. I. Cuppens and K. Houthoofd are thanked for the ICP and AAS measurements. R.Y. acknowledges Chinese Scholarship Council for a CSC doctoral fellowship. JAM and CEAK acknowledge the Flemish government for long-term structural funding (Methusalem). N.C. and S.B. acknowledge financial support from European Research Council (ERC Starting Grant #335078-COLOURATOMS).; ECAS_Sara; (ROMEO:yellow; preprint:; postprint:restricted ; pdfversion:cannot); |
Approved |
Most recent IF: 3.269 |
|
Call Number |
c:irua:133671 |
Serial |
4027 |
Permanent link to this record |
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Author |
Savina, A.A.; Saiutina, V.V.; Morozov, A.V.; Boev, A.O.; Aksyonov, D.A.; Dejoie, C.; Batuk, M.; Bals, S.; Hadermann, J.; Abakumov, A.M. |
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Title |
Chemistry, local molybdenum clustering, and electrochemistry in the Li2+xMo1-xO3 solid solutions |
Type |
A1 Journal article |
|
Year |
2022 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
|
Volume |
61 |
Issue |
14 |
Pages |
5637-5652 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
A broad range of cationic nonstoichiometry has been demonstratedfor the Li-rich layered rock-salt-type oxide Li2MoO3, which has generally been considered as a phase with a well-defined chemical composition. Li2+xMo1-xO3(-0.037 <= x <= 0.124) solid solutions were synthesized via hydrogen reduction ofLi2MoO4in the temperature range of 650-1100 degrees C, withxdecreasing with theincrease of the reduction temperature. The solid solutions adopt a monoclinicallydistorted O3-type layered average structure and demonstrate a robust localordering of the Li cations and Mo3triangular clusters within the mixed Li/Mocationic layers. The local structure was scrutinized in detail by electron diffractionand aberration-corrected scanning transmission electron microcopy (STEM),resulting in an ordering model comprising a uniform distribution of the Mo3clusters compatible with local electroneutrality and chemical composition. The geometry of the triangular clusters with their oxygenenvironment (Mo3O13groups) has been directly visualized using differential phase contrast STEM imaging. The established localstructure was used as input for density functional theory (DFT)-based calculations; they support the proposed atomic arrangementand provide a plausible explanation for the staircase galvanostatic charge profiles upon electrochemical Li+extraction fromLi2+xMo1-xO3in Li cells. According to DFT, all electrochemical capacity in Li2+xMo1-xO3solely originates from the cationic Moredox process, which proceeds via oxidation of the Mo3triangular clusters into bent Mo3chains where the electronic capacity of the clusters depends on the initial chemical composition and Mo oxidation state defining the width of the first charge low-voltageplateau. Further oxidation at the high-voltage plateau proceeds through decomposition of the Mo3chains into Mo2dimers and further into individual Mo6+cations |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000789034200023 |
Publication Date |
2022-04-01 |
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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 |
0020-1669 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
4.6 |
Times cited |
3 |
Open Access |
Not_Open_Access |
|
Notes |
The authors acknowledge Russian Science Foundation (grant 20-43-01012) and Research Foundation Flanders (FWO Vlaanderen, project number G0F1320N) for financial support. The authors are grateful to AICF of Skoltech for providing access to electron microscopy equipment. The authors are grateful to Prof. G. Van Tendeloo for discussing the results. |
Approved |
Most recent IF: 4.6 |
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Call Number |
UA @ admin @ c:irua:188631 |
Serial |
7079 |
Permanent link to this record |
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Author |
Duarte, M.; Daems, N.; Hereijgers, J.; Arenas Esteban, D.; Bals, S.; Breugelmans, T. |
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Title |
Enhanced CO2 electroreduction with metal-nitrogen-doped carbons in a continuous flow reactor |
Type |
A1 Journal article |
|
Year |
2021 |
Publication |
Journal Of Co2 Utilization |
Abbreviated Journal |
J Co2 Util |
|
Volume |
50 |
Issue |
|
Pages |
101583-12 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT) |
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Abstract |
As part of a mitigation and adaptation approach to increasing carbon dioxide atmospheric concentrations, we report superior performance of various metal-nitrogen-doped carbon catalysts, synthesized using an easily up-scalable method, for the electrochemical reduction to carbon monoxide and/or formate at industrially relevant current densities up to 200 mAcm−2. Altering the embedded transition metal (i.e. Sn, Co, Fe, Mn and Ni) allowed to tune the selectivity towards the desired product. Mn-N-C and Fe-N-C performance was compromised by its high CO* binding energy, while Co-N-C catalyzed preferentially the HER. Ni-N-C and Sn-N-C revealed to be promising electrocatalysts, the latter being evaluated for the first time in a flow reactor. A productivity of 589 L CO m-2 h-1 at -1.39 VRHE with Ni-N-C and 751 g HCOO- m-2 h-1 at -1.47 VRHE with Sn-N-C was achieved with no signs of degradation detected after 24 h of operation at industrially relevant current densities (100 mAcm−2). Stable operation at 200 mAcm−2 led to turnover frequencies for the production of carbon products of up to 5176 h-1. These enhanced productivities, in combination with high stability, constitute an essential step towards the scalability and ultimately towards the economical valorization of CO2 electrolyzers using metal-containing nitrogen-doped catalysts. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000670316000002 |
Publication Date |
2021-05-28 |
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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 |
2212-9820 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
4.292 |
Times cited |
14 |
Open Access |
OpenAccess |
|
Notes |
The authors acknowledge sponsoring from the Research Foundation – Flanders (FWO) in the frame of a post-doctoral grant (12Y3919N – ND). This project was co-funded by the Interreg 2 Seas-Program 2014-2020, co-financed by the European Fund for Regional Development in the frame of subsidiary contract nr. 2S03-019. This work was further performed in the framework of the Catalisti MOT project D2M (“Dioxide to Monoxide (D2M): Innovative catalysis for CO2 to CO conversion”). We thank Lien Pacquets for analyzing the samples with SEM-EDX, Saskia Defoss´e for helping with the N2 physisorption measurements and Kitty Baert (VUB) for analyzing the samples with XPS and Raman. |
Approved |
Most recent IF: 4.292 |
|
Call Number |
UA @ admin @ c:irua:178151 |
Serial |
6779 |
Permanent link to this record |
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Author |
Pramanik, G.; Kvakova, K.; Thottappali, M.A.; Rais, D.; Pfleger, J.; Greben, M.; El-Zoka, A.; Bals, S.; Dracinsky, M.; Valenta, J.; Cigler, P. |
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Title |
Inverse heavy-atom effect in near infrared photoluminescent gold nanoclusters |
Type |
A1 Journal article |
|
Year |
2021 |
Publication |
Nanoscale |
Abbreviated Journal |
Nanoscale |
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Volume |
12 |
Issue |
23 |
Pages |
10462-10467 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
Fluorophores functionalized with heavy elements show enhanced intersystem crossing due to increased spin-orbit coupling, which in turn shortens the fluorescence decay lifetime (tau(PL)). This phenomenon is known as the heavy-atom effect (HAE). Here, we report the observation of increased tau(PL) upon functionalisation of near-infrared photoluminescent gold nanoclusters with iodine. The heavy atom-mediated increase in tau(PL) is in striking contrast with the HAE and referred to as inverse HAE. Femtosecond and nanosecond transient absorption spectroscopy revealed overcompensation of a slight decrease in lifetime of the transition associated with the Au core (ps) by a large increase in the long-lived triplet state lifetime associated with the Au shell, which contributed to the observed inverse HAE. This unique observation of inverse HAE in gold nanoclusters provides the means to enhance the triplet excited state lifetime. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000657052500001 |
Publication Date |
2021-06-30 |
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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 |
|
Impact Factor |
7.367 |
Times cited |
1 |
Open Access |
OpenAccess |
|
Notes |
The authors acknowledge support from GACR project no. 18-12533S. G. P. acknowledges support from EUSMI project no. E180200060; J. P. from the Ministry of Education, Youth and Sports of the Czech Republic – Program INTER-EXCELLENCE (LTAUSA19066). |
Approved |
Most recent IF: 7.367 |
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Call Number |
UA @ admin @ c:irua:179052 |
Serial |
6843 |
Permanent link to this record |
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Author |
Pramanik, G.; Kvakova, K.; Thottappali, M.A.; Rais, D.; Pfleger, J.; Greben, M.; El-Zoka, A.; Bals, S.; Dracinsky, M.; Valenta, J.; Cigler, P. |
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Title |
Inverse heavy-atom effect in near infrared photoluminescent gold nanoclusters |
Type |
A1 Journal Article |
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Year |
2021 |
Publication |
Nanoscale |
Abbreviated Journal |
Nanoscale |
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Volume |
13 |
Issue |
23 |
Pages |
10462-10467 |
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Keywords |
A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; |
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Abstract |
Fluorophores functionalized with heavy elements show enhanced intersystem crossing due to increased spin–orbit coupling, which in turn shortens the fluorescence decay lifetime (<italic>τ</italic><sup>PL</sup>). This phenomenon is known as the heavy-atom effect (HAE). Here, we report the observation of increased<italic>τ</italic><sup>PL</sup>upon functionalisation of near-infrared photoluminescent gold nanoclusters with iodine. The heavy atom-mediated increase in<italic>τ</italic><sup>PL</sup>is in striking contrast with the HAE and referred to as inverse HAE. Femtosecond and nanosecond transient absorption spectroscopy revealed overcompensation of a slight decrease in lifetime of the transition associated with the Au core (ps) by a large increase in the long-lived triplet state lifetime associated with the Au shell, which contributed to the observed inverse HAE. This unique observation of inverse HAE in gold nanoclusters provides the means to enhance the triplet excited state lifetime. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
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Publication Date |
2021-05-24 |
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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 |
2040-3364 |
ISBN |
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Additional Links |
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Impact Factor |
7.367 |
Times cited |
7 |
Open Access |
OpenAccess |
|
Notes |
The authors acknowledge support from GACR project Nr.18- 12533S. G. P. acknowledges support from EUSMI project No. E180200060; J.P. from the Ministry of Education, Youth and Sports of the Czech Republic – Program INTER-EXCELLENCE (LTAUSA19066). |
Approved |
Most recent IF: 7.367 |
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Call Number |
EMAT @ emat @ |
Serial |
6950 |
Permanent link to this record |
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Author |
Juchtmans, R.; Verbeeck, J. |
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Title |
Local orbital angular momentum revealed by spiral-phase-plate imaging in transmission-electron microscopy |
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 |
023811 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The orbital angular momentum (OAM) of light and matter waves is a parameter that has been getting increasingly more attention over the past couple of years. Beams with a well-defined OAM, the so-called vortex beams, are applied already in, e.g., telecommunication, astrophysics, nanomanipulation, and chiral measurements in optics and electron microscopy. Also, the OAM of a wave induced by the interaction with a sample has attracted a lot of interest. In all these experiments it is crucial to measure the exact (local) OAM content of the wave, whether it is an incoming vortex beam or an exit wave after interacting with a sample. In this work we investigate the use of spiral phase plates (SPPs) as an alternative to the programmable phase plates used in optics to measure OAM. We derive analytically how these can be used to study the local OAM components of any wave function. By means of numerical simulations we illustrate how the OAM of a pure vortex beam can be measured. We also look at a sum of misaligned vortex beams and show how, by using SPPs, the position and the OAM of each individual beam can be detected. Finally, we look at the OAM induced by a magnetic dipole on a free-electron wave and show how the SPP can be used to localize the magnetic poles and measure their “magnetic charge.” Although our findings can be applied to study the OAM of any wave function, our findings are of particular interest for electron microscopy where versatile programmable phase plates do not yet exist. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000369367700006 |
Publication Date |
2016-02-06 |
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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 |
12 |
Open Access |
|
|
Notes |
The authors acknowledge support from the Aspirant Fonds Wetenschappelijk Onderzoek–Vlaanderen (FPO), the EU un- der the Seventh Framework Program (FP7) under a contract for an Integrated Infrastructure Initiative, Reference No. 312483- ESTEEM2, and the ERC Starting Grant 278510 VORTEX.; esteem2jra2 ECASJO; |
Approved |
Most recent IF: 2.925 |
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Call Number |
c:irua:131613 c:irua:131613UA @ admin @ c:irua:131613 |
Serial |
4030 |
Permanent link to this record |
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Author |
Leusink, D.P.; Coneri, F.; Hoek, M.; Turner, S.; Idrissi, H.; Van Tendeloo, G.; Hilgenkamp, H. |
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Title |
Thin films of the spin ice compound Ho2Ti2O7 |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
APL materials |
Abbreviated Journal |
Apl Mater |
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Volume |
2 |
Issue |
3 |
Pages |
032101-32107 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
The pyrochlore compounds Ho2Ti2O7 and Dy2Ti2O7 show an exotic form of magnetism called the spin ice state, resulting from the interplay between geometrical frustration and ferromagnetic coupling. A fascinating feature of this state is the appearance of magnetic monopoles as emergent excitations above the degenerate ground state. Over the past years, strong effort has been devoted to the investigation of these monopoles and other properties of the spin ice state in bulk crystals. Here, we report the fabrication of Ho2Ti2O7 thin films using pulsed laser deposition on yttria-stabilized ZrO2 substrates. We investigated the structural properties of these films by X-ray diffraction, scanning transmission electron microscopy, and atomic force microscopy, and the magnetic properties by vibrating sample magnetometry at 2 K. The films not only show a high crystalline quality, but also exhibit the hallmarks of a spin ice: a pronounced magnetic anisotropy and an intermediate plateau in the magnetization along the [111] crystal direction. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000334220300002 |
Publication Date |
2014-03-04 |
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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 |
2166-532X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.335 |
Times cited |
18 |
Open Access |
|
|
Notes |
The authors acknowledge support from the Dutch FOM and NWO foundations and from the European Union under the Framework 7 program under a contract from an Integrated Infrastructure Initiative (Reference 312483 ESTEEM2). G.V.T. acknowledges the ERC Grant N246791- COUNTATOMS. S.T. gratefully acknowledges financial support from the Fund for Scientific Research Flanders (FWO). H.I. acknowledges the IAP program of the Belgian State Federal Office for Scientific, Technical and Cultural Affairs under Contract No. P7/21. The microscope used in this study was partially financed by the Hercules Foundation of the Flemish Government. The authors acknowledge fruitful interactions with A. Brinkman, M. G. Blamire, M. Egilmez, F. J. G. Roesthuis, J. N. Beukers, C. G. Molenaar, M. Veldhorst, and X. Renshaw Wang; esteem2_ta |
Approved |
Most recent IF: 4.335; 2014 IF: NA |
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Call Number |
UA @ lucian @ c:irua:115555 |
Serial |
3641 |
Permanent link to this record |
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Author |
Juchtmans, R.; Verbeeck, J. |
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Title |
Orbital angular momentum in electron diffraction and its use to determine chiral crystal symmetries |
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 |
92 |
Issue |
92 |
Pages |
134108 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
In this work we present an alternative way to look at electron diffraction in a transmission electron microscope.
Instead of writing the scattering amplitude in Fourier space as a set of plane waves,we use the cylindrical Fourier transform to describe the scattering amplitude in a basis of orbital angular momentum (OAM) eigenstates. We show how working in this framework can be very convenient when investigating, e.g., rotation and screw-axis symmetries. For the latter we find selection rules on the OAM coefficients that unambiguously reveal the handedness of the screw axis. Detecting the OAM coefficients of the scattering amplitude thus offers the possibility to detect the handedness of crystals without the need for dynamical simulations, the thickness of the sample, nor the exact crystal structure. We propose an experimental setup to measure the OAM components where an image of the crystal is taken after inserting a spiral phase plate in the diffraction plane and perform multislice simulations on α quartz to demonstrate how the method indeed reveals the chirality. The experimental feasibility of the technique is discussed together with its main advantages with respect to chirality determination of screw axes. The method shows how the use of a spiral phase plate can be extended from a simple phase imaging technique to a tool to measure the local OAM decomposition of an electron wave, widening the field of interest well beyond chiral space group determination. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000362893100002 |
Publication Date |
2015-10-14 |
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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 |
|
Impact Factor |
3.836 |
Times cited |
16 |
Open Access |
|
|
Notes |
The authors acknowledge support from the FWO (As- pirant Fonds Wetenschappelijk Onderzoek–Vlaanderen), the EU under the Seventh Framework Program (FP7) under a contract for an Integrated Infrastructure Initiative, Reference No. 312483-ESTEEM2, and ERC Starting Grant No. 278510 VORTEX; esteem2jra1; ECASJO; |
Approved |
Most recent IF: 3.836; 2015 IF: 3.736 |
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Call Number |
c:irua:129417 c:irua:129417UA @ admin @ c:irua:129417 |
Serial |
4089 |
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Author |
Juchtmans, R.; Clark, L.; Lubk, A.; Verbeeck, J. |
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Title |
Spiral phase plate contrast in optical and electron microscopy |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Physical review A |
Abbreviated Journal |
Phys Rev A |
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Volume |
94 |
Issue |
94 |
Pages |
023838 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The use of phase plates in the back focal plane of a microscope is a well-established technique in optical microscopy to increase the contrast of weakly interacting samples and is gaining interest in electron microscopy as well. In this paper we study the spiral phase plate (SPP), also called helical, vortex, or two-dimensional Hilbert phase plate, which adds an angularly dependent phase of the form exp(iℓϕk) to the exit wave in Fourier space. In the limit of large collection angles, we analytically calculate that the average of a pair of l=+-1
SPP filtered images is directly proportional to the gradient squared of the exit wave, explaining the edge contrast previously seen in optical SPP work. We discuss the difference between a clockwise-anticlockwise pair of SPP filtered images and derive conditions under which the modulus of the wave's gradient can be seen directly from one SPP filtered image. This work provides the theoretical background to interpret images obtained with a SPP, thereby opening new perspectives for new experiments to study, for example, magnetic materials in an electron microscope. |
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Wos |
000381882800011 |
Publication Date |
2016-08-22 |
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ISSN |
2469-9926 |
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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 |
10 |
Open Access |
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Notes |
The authors acknowledge support from the FWO (Aspirant Fonds Wetenschappelijk Onderzoek – Vlaanderen) and the EU under the Seventh Framework Program (FP7) under a contract for an Integrated Infrastructure Initiative, Reference No. 312483-ESTEEM2 and ERC Starting Grant No. 278510 VORTEX.; ECASJO_ |
Approved |
Most recent IF: 2.925 |
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Call Number |
EMAT @ emat @ c:irua:140086 |
Serial |
4418 |
Permanent link to this record |