Records |
Author |
Guzzinati, G.; Ghielens, W.; Mahr, C.; Béché, A.; Rosenauer, A.; Calders, T.; Verbeeck, J. |
Title |
Electron Bessel beam diffraction patterns, line scan of Si/SiGe multilayer |
Type |
Dataset |
Year |
2019 |
Publication |
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Abbreviated Journal |
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Volume |
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Issue |
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Pages |
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Keywords |
Dataset; ADReM Data Lab (ADReM); Electron microscopy for materials research (EMAT) |
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Place of Publication |
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Wos |
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Publication Date |
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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 |
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ISBN |
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Additional Links |
UA library record |
Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
no |
Call Number |
UA @ admin @ c:irua:169114 |
Serial |
6865 |
Permanent link to this record |
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Author |
Rosenauer, A.; Gerthsen, D.; Van Aert, S.; van Dyck, D.; den Dekker, A.J. |
Title |
Present state of the composition evaluation of ternary semiconductor nanostructures by lattice fringe analysis |
Type |
A1 Journal article |
Year |
2003 |
Publication |
Institute of physics conference series |
Abbreviated Journal |
|
Volume |
|
Issue |
180 |
Pages |
19-22 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
Abstract |
Semiconductor heterostructures are used for the fabrication of optoelectronic devices. Performance of such devices is governed by their chemical morphology. The composition distribution of quantum wells and dots is influenced by kinetic growth processes which are not understood completely at present. To obtain more information about these effects, methods for composition determination with a spatial resolution at a near atomic scale are necessary. In this paper we focus on the present state of the composition evaluation by the lattice fringe analysis (CELFA) technique and explain the basic ideas, optimum imaging conditions, precision and accuracy. |
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Place of Publication |
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Language |
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Wos |
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Publication Date |
0000-00-00 |
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 |
0-7503-0979-2 |
ISBN |
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Additional Links |
UA library record; WoS full record; |
Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
Most recent IF: NA |
Call Number |
UA @ lucian @ c:irua:95118 |
Serial |
2710 |
Permanent link to this record |
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Author |
Guzzinati, G.; Ghielens, W.; Mahr, C.; Béché, A.; Rosenauer, A.; Calders, T.; Verbeeck, J. |
Title |
Electron Bessel beam diffraction for precise and accurate nanoscale strain mapping |
Type |
A1 Journal article |
Year |
2019 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
Volume |
114 |
Issue |
24 |
Pages |
243501 |
Keywords |
A1 Journal article; ADReM Data Lab (ADReM); Electron microscopy for materials research (EMAT) |
Abstract |
Strain has a strong effect on the properties of materials and the performance of electronic devices. Their ever shrinking size translates into a constant demand for accurate and precise measurement methods with a very high spatial resolution. In this regard, transmission electron microscopes are key instruments thanks to their ability to map strain with a subnanometer resolution. Here, we present a method to measure strain at the nanometer scale based on the diffraction of electron Bessel beams. We demonstrate that our method offers a strain sensitivity better than 2.5 × 10−4 and an accuracy of 1.5 × 10−3, competing with, or outperforming, the best existing methods with a simple and easy to use experimental setup. |
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 |
000472599100019 |
Publication Date |
2019-06-17 |
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 |
0003-6951 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.411 |
Times cited |
17 |
Open Access |
OpenAccess |
Notes |
Deutsche Forschungsgemeinschaft, RO2057/12-2 ; Fonds Wetenschappelijk Onderzoek, G.0934.17N ; |
Approved |
Most recent IF: 3.411 |
Call Number |
EMAT @ emat @UA @ admin @ c:irua:160119 |
Serial |
5181 |
Permanent link to this record |
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Author |
Schowalter, M.; Rosenauer, A.; Lamoen, D.; Kruse, P.; Gerthsen, D. |
Title |
Ab initio computation of the mean inner Coulomb potential of wurtzite-type semiconductors and gold |
Type |
A1 Journal article |
Year |
2006 |
Publication |
Applied Physics Letters |
Abbreviated Journal |
Appl Phys Lett |
Volume |
88 |
Issue |
23 |
Pages |
Artn 232108 |
Keywords |
A1 Journal article; Electron Microscopy for Materials Science (EMAT); |
Abstract |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
Language |
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Wos |
000238914500031 |
Publication Date |
2006-06-19 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0003-6951; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.411 |
Times cited |
8 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.411; 2006 IF: 3.977 |
Call Number |
UA @ lucian @ c:irua:60581 |
Serial |
33 |
Permanent link to this record |
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Author |
Schowalter, M.; Lamoen, D.; Kruse, P.; Gerthsen, D.; Rosenauer, A. |
Title |
First-principles calculations of the mean inner Coulomb potential for sphalerite type II.VI semiconductors |
Type |
A1 Journal article |
Year |
2004 |
Publication |
Applied Physics Letters |
Abbreviated Journal |
Appl Phys Lett |
Volume |
85 |
Issue |
21 |
Pages |
4938-4940 |
Keywords |
A1 Journal article; Electron Microscopy for Materials Science (EMAT); |
Abstract |
|
Address |
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Corporate Author |
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Thesis |
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Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000225300600037 |
Publication Date |
2004-11-24 |
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 |
0003-6951; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.411 |
Times cited |
16 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.411; 2004 IF: 4.308 |
Call Number |
UA @ lucian @ c:irua:49657 |
Serial |
1203 |
Permanent link to this record |
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Author |
Müller, E.; Kruse, P.; Gerthsen, D.; Schowalter, M.; Rosenauer, A.; Lamoen, D.; Kling, R.; Waag, A. |
Title |
Measurement of the mean inner potential of ZnO nanorods by transmission electron holography |
Type |
A1 Journal article |
Year |
2005 |
Publication |
Applied Physics Letters |
Abbreviated Journal |
Appl Phys Lett |
Volume |
86 |
Issue |
15 |
Pages |
|
Keywords |
A1 Journal article; Electron Microscopy for Materials Science (EMAT); |
Abstract |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000228901600121 |
Publication Date |
2005-04-06 |
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 |
0003-6951; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.411 |
Times cited |
5 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.411; 2005 IF: 4.127 |
Call Number |
UA @ lucian @ c:irua:54917 |
Serial |
1963 |
Permanent link to this record |
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Author |
Gonnissen, J.; de Backer, A.; den Dekker, A.J.; Martinez, G.T.; Rosenauer, A.; Sijbers, J.; Van Aert, S. |
Title |
Optimal experimental design for the detection of light atoms from high-resolution scanning transmission electron microscopy images |
Type |
A1 Journal article |
Year |
2014 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
Volume |
105 |
Issue |
6 |
Pages |
063116 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
Abstract |
We report an innovative method to explore the optimal experimental settings to detect light atoms from scanning transmission electron microscopy (STEM) images. Since light elements play a key role in many technologically important materials, such as lithium-battery devices or hydrogen storage applications, much effort has been made to optimize the STEM technique in order to detect light elements. Therefore, classical performance criteria, such as contrast or signal-to-noise ratio, are often discussed hereby aiming at improvements of the direct visual interpretability. However, when images are interpreted quantitatively, one needs an alternative criterion, which we derive based on statistical detection theory. Using realistic simulations of technologically important materials, we demonstrate the benefits of the proposed method and compare the results with existing approaches. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000341188700073 |
Publication Date |
2014-08-14 |
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 |
0003-6951;1077-3118; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.411 |
Times cited |
12 |
Open Access |
|
Notes |
FWO (G.0393.11; G.0064.10; and G.0374.13); European Union Seventh Framework Programme [FP7/2007-2013] under Grant Agreement No. 312483 (ESTEEM2); esteem2_jra2 |
Approved |
Most recent IF: 3.411; 2014 IF: 3.302 |
Call Number |
UA @ lucian @ c:irua:118333 |
Serial |
2482 |
Permanent link to this record |
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|
|
Author |
Titantah, J.T.; Lamoen, D.; Schowalter, M.; Rosenauer, A. |
Title |
Density-functional theory calculations of the electron energy-loss near-edge structure of Li-intercalated graphite |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Carbon |
Abbreviated Journal |
Carbon |
Volume |
47 |
Issue |
10 |
Pages |
2501-2510 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
We have studied the structural and electronic properties of lithium-intercalated graphite (LIG) for various Li content. Atomic relaxation shows that Li above the center of the carbon hexagon in a AAAA stacked graphite is the only stable Li configuration in stage 1 intercalated graphite. Lithium and Carbon 1s energy-loss near-edge structure (ELNES) calculations are performed on the Li-intercalated graphite using the core-excited density-functional theory formulation. Several features of the Li 1s ELNES are correlated with reported experimental features. The ELNES spectra of Li is found to be electron beam orientation sensitive and this property is used to assign the origin of the various Li 1s ELNES features. Information about core-hole screening by the valence electrons and charge transfer in the LIG systems is obtained from the C 1s ELNES and valence charge density difference calculations, respectively. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Oxford |
Editor |
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Language |
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Wos |
000268429000025 |
Publication Date |
2009-05-11 |
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 |
0008-6223; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.337 |
Times cited |
12 |
Open Access |
|
Notes |
Fwo G.0425.05; Esteem 026019 |
Approved |
Most recent IF: 6.337; 2009 IF: 4.504 |
Call Number |
UA @ lucian @ c:irua:77973 |
Serial |
638 |
Permanent link to this record |
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|
|
Author |
Titantah, J.T.; Lamoen, D.; Schowalter, M.; Rosenauer, A. |
Title |
Bond length variation in Ga1-xInxAs crystals from the Tersoff potential |
Type |
A1 Journal article |
Year |
2007 |
Publication |
Journal of applied physics |
Abbreviated Journal |
J Appl Phys |
Volume |
101 |
Issue |
12 |
Pages |
123508,1-4 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
|
Address |
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Corporate Author |
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Thesis |
|
Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
Language |
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Wos |
000247625700034 |
Publication Date |
2007-06-20 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0021-8979; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.068 |
Times cited |
19 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.068; 2007 IF: 2.171 |
Call Number |
UA @ lucian @ c:irua:67460 |
Serial |
247 |
Permanent link to this record |
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|
|
Author |
Titantah, J.T.; Lamoen, D.; Schowalter, M.; Rosenauer, A. |
Title |
Modified atomic scattering amplitudes and size effects on the 002 and 220 electron structure factors of multiple Ga1-xInxAs/GaAs quantum wells |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Journal of applied physics |
Abbreviated Journal |
J Appl Phys |
Volume |
105 |
Issue |
8 |
Pages |
084310,1-084310,8 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The modified atomic scattering amplitudes (MASAs) of mixed Ga<sub>1-x</sub>In<sub>x</sub>As, GaAs<sub>1-x</sub>N<sub>x</sub>, and InAs<sub>1-x</sub>N<sub>x</sub> are calculated using the density functional theory approach and the results are compared with those of the binary counterparts. The MASAs of N, Ga, As, and In for various scattering vectors in various chemical environments and in the zinc-blende structure are compared with the frequently used Doyle and Turner values. Deviation from the Doyle and Turner results is found for small scattering vectors (s<0.3 Å<sup>-1</sup>) and for these scattering vectors the MASAs are found to be sensitive to the orientation of the scattering vector and on the chemical environment. The chemical environment sensitive MASAs are used within zero pressure classical Metropolis Monte Carlo, finite temperature calculations to investigate the effect of well size on the electron 002 and 220 structure factors (SFs). The implications of the use of the 002 (200) spot for the quantification of nanostructured Ga<sub>1-x</sub>In<sub>x</sub>As systems are examined while the 220 SF across the well is evaluated and is found to be very sensitive to the in-plane static displacements. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
Language |
|
Wos |
000268064700149 |
Publication Date |
2009-04-23 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0021-8979; |
ISBN |
|
Additional Links |
UA library record; WoS full record |
Impact Factor |
2.068 |
Times cited |
|
Open Access |
|
Notes |
Fwo G.0425.05; Esteem 026019 |
Approved |
Most recent IF: 2.068; 2009 IF: 2.072 |
Call Number |
UA @ lucian @ c:irua:78282 |
Serial |
2160 |
Permanent link to this record |
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Author |
Mahr, C.; Kundu, P.; Lackmann, A.; Zanaga, D.; Thiel, K.; Schowalter, M.; Schwan, M.; Bals, S.; Wittstock, A.; Rosenauer, A. |
Title |
Quantitative determination of residual silver distribution in nanoporous gold and its influence on structure and catalytic performance |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Journal of catalysis |
Abbreviated Journal |
J Catal |
Volume |
352 |
Issue |
352 |
Pages |
52-58 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Large efforts have been made trying to understand the origin of the high catalytic activity of dealloyed nanoporous gold as a green catalyst for the selective promotion of chemical reactions at low temperatures. Residual silver, left in the sample after dealloying of a gold-silver alloy, has been shown to have a strong influence on the activity of the catalyst. But the question of how the silver is distributed within the porous structure has not finally been answered yet. We show by quantitative energy dispersive X-ray tomography measurements that silver forms clusters that are distributed irregularly, both on the surface and inside the ligaments building up the porous structure. Furthermore, we find that the role of the residual silver is ambiguous. Whereas CO oxidation is supported by more residual silver, methanol oxidation to methyl formate is hindered. Structural characterisation reveals larger ligaments and pores for decreasing residual silver concentration. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
|
Editor |
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Language |
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Wos |
000408299600006 |
Publication Date |
2017-05-29 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0021-9517 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.844 |
Times cited |
42 |
Open Access |
OpenAccess |
Notes |
This work was supported by the Deutsche Forschungsgemeinschaft (DFG) under contracts no. RO2057/12-1 (SP 6) and WI4497/1-1 (SP 2) within the research unit FOR2213 (www.nagocat. de) and the European Research Council (ERC Starting Grant No. 335078-COLOURATOMS). (ROMEO:green; preprint:; postprint:can ; pdfversion:cannot); ecas_sara |
Approved |
Most recent IF: 6.844 |
Call Number |
EMAT @ emat @c:irua:144434UA @ admin @ c:irua:144434 |
Serial |
4623 |
Permanent link to this record |
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|
|
Author |
Müller-Caspary, K.; Grieb, T.; Müßener, J.; Gauquelin, N.; Hille, P.; Schörmann, J.; Verbeeck, J.; Van Aert, S.; Eickhoff, M.; Rosenauer, A. |
Title |
Electrical Polarization in AlN/GaN Nanodisks Measured by Momentum-Resolved 4D Scanning Transmission Electron Microscopy |
Type |
A1 Journal article |
Year |
2019 |
Publication |
Physical review letters |
Abbreviated Journal |
Phys Rev Lett |
Volume |
122 |
Issue |
10 |
Pages |
106102 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
We report the mapping of polarization-induced internal electric fields in AlN/GaN nanowire heterostructures at unit cell resolution as a key for the correlation of optical and structural phenomena in semiconductor optoelectronics. Momentum-resolved aberration-corrected scanning transmission electron microscopy is employed as a new imaging mode that simultaneously provides four-dimensional data in real and reciprocal space. We demonstrate how internal mesoscale and atomic electric fields can be separated in an experiment, which is verified by comprehensive dynamical simulations of multiple electron scattering. A mean difference of 5.3 +- 1.5 MV/cm is found for the polarization-induced electric fields in AlN and GaN, being in accordance with dedicated simulations and photoluminescence measurements in previous publications. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
|
Editor |
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Language |
|
Wos |
000461067700007 |
Publication Date |
2019-03-11 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0031-9007 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
8.462 |
Times cited |
26 |
Open Access |
OpenAccess |
Notes |
The authors gratefully acknowledge the help of Natalie Claes for analyzing the EDX data. K. M.-C. acknowledges funding from the Initiative and Network Fund of the Helmholtz Association within the Helmholtz Young Investigator Group moreSTEM under Contract No. VHNG- 1317 at Forschungszentrum Jülich in Germany. The direct electron detector (Medipix3, Quantum Detectors) was funded by the Hercules fund from the Flemish Government. N. G. and J. V. acknowledge funding from the Geconcentreerde Onderzoekacties project Solarpaint of the University of Antwerp. T. G. and A. R. acknowledge support from the Deutsche Forschungsgemeinschaft (Germany) under Contract No. RO2057/8-3. This work also received funding from the European Research Council under the European Union’s Horizon 2020 research and innovation programme (Contract No. 770887). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project funding (G.0368.15N).; Helmholtz Association, VH-NG-1317 ; Forschungszentrum Jülich; Flemish Government; Universiteit Antwerpen; Deutsche Forschungsgemeinschaft, RO2057/8-3 ; H2020 European Research Council, 770887 ; Fonds Wetenschappelijk Onderzoek, G.0368.15N ; |
Approved |
Most recent IF: 8.462 |
Call Number |
UA @ lucian @UA @ admin @ c:irua:158120 |
Serial |
5157 |
Permanent link to this record |
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|
|
Author |
Schowalter, M.; Rosenauer, A.; Titantah, J.T.; Lamoen, D. |
Title |
Computation and parametrization of the temperature dependence of Debye-Waller factors for group IV, III-V and II-VI semiconductors |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Acta crystallographica: section A: foundations of crystallography |
Abbreviated Journal |
Acta Crystallogr A |
Volume |
65 |
Issue |
1 |
Pages |
5-17 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
We calculated the temperature dependence of the Debye-Waller factors for a variety of group IV, III-V and II-VI semiconductors from 0.1 to 1000 K. The approach used to fit the temperature dependence is described and resulting fit parameters are tabulated for each material. The Debye-Waller factors are deduced from generalized phonon densities of states which were derived from first principles using the WIEN2k and the ABINIT codes. |
Address |
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Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
Copenhagen |
Editor |
|
Language |
|
Wos |
000261799500002 |
Publication Date |
2008-11-05 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0108-7673; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
5.725 |
Times cited |
51 |
Open Access |
|
Notes |
Fwo G.0425.05; Esteem 026019 |
Approved |
Most recent IF: 5.725; 2009 IF: 49.926 |
Call Number |
UA @ lucian @ c:irua:72918 |
Serial |
453 |
Permanent link to this record |
|
|
|
Author |
Schowalter, M.; Rosenauer, A.; Titantah, J.T.; Lamoen, D. |
Title |
Temperature-dependent Debye-Waller factors for semiconductors with the wurtzite-type structure |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Acta crystallographica: section A: foundations of crystallography |
Abbreviated Journal |
Acta Crystallogr A |
Volume |
65 |
Issue |
|
Pages |
227-231 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
We computed Debye-Waller factors in the temperature range from 0.1 to 1000 K for AlN, GaN, InN, ZnO and CdO with the wurtzite-type structure. The Debye-Waller factors were derived from phonon densities of states obtained from Hellmann-Feynman forces computed within the density-functional-theory formalism. The temperature dependences of the Debye-Waller factors were fitted and fit parameters are given. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
Copenhagen |
Editor |
|
Language |
|
Wos |
000264927100006 |
Publication Date |
2009-03-12 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0108-7673; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
5.725 |
Times cited |
23 |
Open Access |
|
Notes |
Fwo G.0425.05; Esteem 026019 |
Approved |
Most recent IF: 5.725; 2009 IF: 49.926 |
Call Number |
UA @ lucian @ c:irua:74565 |
Serial |
3497 |
Permanent link to this record |
|
|
|
Author |
Muller-Caspary, K.; Krause, F.F.; Grieb, T.; Loffler, S.; Schowalter, M.; Béché, A.; Galioit, V.; Marquardt, D.; Zweck, J.; Schattschneider, P.; Verbeeck, J.; Rosenauer, A. |
Title |
Measurement of atomic electric fields and charge densities from average momentum transfers using scanning transmission electron microscopy |
Type |
A1 Journal article |
Year |
2016 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
178 |
Issue |
178 |
Pages |
62-80 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
This study sheds light on the prerequisites, possibilities, limitations and interpretation of high-resolution differential phase contrast (DPC) imaging in scanning transmission electron microscopy (STEM). We draw particular attention to the well-established DPC technique based on segmented annular detectors and its relation to recent developments based on pixelated detectors. These employ the expectation value of the momentum transfer as a reliable measure of the angular deflection of the STEM beam induced by an electric field in the specimen. The influence of scattering and propagation of electrons within the specimen is initially discussed separately and then treated in terms of a two-state channeling theory. A detailed simulation study of GaN is presented as a function of specimen thickness and bonding. It is found that bonding effects are rather detectable implicitly, e.g., by characteristics of the momentum flux in areas between the atoms than by directly mapping electric fields and charge densities. For strontium titanate, experimental charge densities are compared with simulations and discussed with respect to experimental artifacts such as scan noise. Finally, we consider practical issues such as figures of merit for spatial and momentum resolution, minimum electron dose, and the mapping of larger-scale, built-in electric fields by virtue of data averaged over a crystal unit cell. We find that the latter is possible for crystals with an inversion center. Concerning the optimal detector design, this study indicates that a sampling of 5mrad per pixel is sufficient in typical applications, corresponding to approximately 10x10 available pixels. |
Address |
Institut fur Festkr perphysik, Universitat Bremen, Otto-Hahn-Allee 1, 28359 Bremen, Germany |
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
English |
Wos |
000403862900009 |
Publication Date |
2016-05-12 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0304-3991 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.843 |
Times cited |
93 |
Open Access |
|
Notes |
K.M.-C. acknowledges support from the Deutsche Forschungsgemeinschaft (DFG) under contract MU3660/1-1. This work was further supported by the DFG under contract RO2057/4-2 and O2057/11-1. J.V. and A.B. acknowledge funding from the European Research Council (ERC) under the 7th Framework Program (FP7), and ERC Starting Grant No. 278510-VORTEX. Experimental results are obtained on the Qu-Ant-EM microscope partly funded by the Hercules fund from the Flemish government. J.V. also acknowledges funding through a GOA project “Solarpaint” of the University of Antwerp. SL and PS acknowledge financial support by the Austrian Science Fund (FWF) under grants No. I543-N20 and J3732-N27. ECASJO_; |
Approved |
Most recent IF: 2.843 |
Call Number |
c:irua:134125UA @ admin @ c:irua:134125 |
Serial |
4098 |
Permanent link to this record |
|
|
|
Author |
van den Bos, K.H.W.; Krause, F.F.; Béché, A.; Verbeeck, J.; Rosenauer, A.; Van Aert, S. |
Title |
Locating light and heavy atomic column positions with picometer precision using ISTEM |
Type |
A1 Journal article |
Year |
2016 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
172 |
Issue |
172 |
Pages |
75-81 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Recently, imaging scanning transmission electron microscopy (ISTEM) has been proposed as a promising new technique combining the advantages of conventional TEM (CTEM) and STEM [1]. The ability to visualize light and heavy elements together makes it a particularly interesting new, spatially incoherent imaging mode. Here, we evaluate this technique in term of precision with which atomic column locations can be measured. By using statistical parameter estimation theory, we will show that these locations can be accurately measured with a precision in the picometer range. Furthermore, a quantitative comparison is made with HAADF STEM imaging to investigate the advantages of ISTEM. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000390600200009 |
Publication Date |
2016-10-09 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0304-3991 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.843 |
Times cited |
8 |
Open Access |
|
Notes |
The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0374.13N, G.0368.15N, G.0369.15N), and by a Ph.D. grant to K.H.W. van den Bos. The research leading to these results has received funding from the Deutsche Forschungsgemeinschaft under Contract No. RO 2057/4-2 and the European Union Seventh Framework Programme under Grant Agreement 312483 – ESTEEM2. We thank Prof. G. Koster from the University of Twente for kindly providing us with the PbTiO3 test sample. |
Approved |
Most recent IF: 2.843 |
Call Number |
EMAT @ emat @ c:irua:136109UA @ admin @ c:irua:136109 |
Serial |
4288 |
Permanent link to this record |
|
|
|
Author |
Alania, M.; De Backer, A.; Lobato, I.; Krause, F.F.; Van Dyck, D.; Rosenauer, A.; Van Aert, S. |
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 |
Volume |
181 |
Issue |
181 |
Pages |
134-143 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
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. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000411170800016 |
Publication Date |
2016-12-15 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0304-3991 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.843 |
Times cited |
3 |
Open Access |
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 |
Call Number |
EMAT @ emat @ c:irua:144432 |
Serial |
4618 |
Permanent link to this record |
|
|
|
Author |
Gauquelin, N.; van den Bos, K.H.W.; Béché, A.; Krause, F.F.; Lobato, I.; Lazar, S.; Rosenauer, A.; Van Aert, S.; Verbeeck, J. |
Title |
Determining oxygen relaxations at an interface: A comparative study between transmission electron microscopy techniques |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
181 |
Issue |
181 |
Pages |
178-190 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Nowadays, aberration corrected transmission electron microscopy (TEM) is a popular method to characterise nanomaterials at the atomic scale. Here, atomically resolved images of nanomaterials are acquired, where the contrast depends on the illumination, imaging and detector conditions of the microscope. Visualization of light elements is possible when using low angle annular dark field (LAADF) STEM, annular bright field (ABF) STEM, integrated differential phase contrast (iDPC) STEM, negative spherical aberration imaging (NCSI) and imaging STEM (ISTEM). In this work, images of a NdGaO3-La0.67Sr0.33MnO3 (NGO-LSMO) interface are quantitatively evaluated by using statistical parameter estimation theory. For imaging light elements, all techniques are providing reliable results, while the techniques based on interference contrast, NCSI and ISTEM, are less robust in terms of accuracy for extracting heavy column locations. In term of precision, sample drift and scan distortions mainly limits the STEM based techniques as compared to NCSI. Post processing techniques can, however, partially compensate for this. In order to provide an outlook to the future, simulated images of NGO, in which the unavoidable presence of Poisson noise is taken into account, are used to determine the ultimate precision. In this future counting noise limited scenario, NCSI and ISTEM imaging will provide more precise values as compared to the other techniques, which can be related to the mechanisms behind the image recording. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000411170800022 |
Publication Date |
2017-06-03 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0304-3991 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.843 |
Times cited |
34 |
Open Access |
OpenAccess |
Notes |
The authors acknowledge financial support from Flanders (FWO, Belgium) through project fundings (G.0044.13N, G.0374.13N, G.0368.15N, G.0369.15N), and by a Ph.D. grant to K.H.W.v.d.B. The Qu-Ant-EM microscope used for this study was partly funded by the Hercules fund from the Flemish Government. A.B. and N.G. acknowledge the EUROTAPES project (FP7-NMP.2011.2.2-1 Grant no.280432) which partly funded this study. N.G., A.B. and J.V. acknowledge funding from the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant 278510 VORTEX. The research leading to these results has received funding from the Deutsche Forschungsgemeinschaft under Contract No. RO 2057/4-2 and the European Union Seventh Framework Programme under Grant Agreement 312483 – ESTEEM2. We thank Prof. G. Koster from the University of Twente for kindly providing us with the LSMO-NGO test sample. |
Approved |
Most recent IF: 2.843 |
Call Number |
EMAT @ emat @ c:irua:144435UA @ admin @ c:irua:144435 |
Serial |
4620 |
Permanent link to this record |
|
|
|
Author |
Grieb, T.; Krause, F.F.; Mahr, C.; Zillmann, D.; Müller-Caspary, K.; Schowalter, M.; Rosenauer, A. |
Title |
Optimization of NBED simulations for disc-detection measurements |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
181 |
Issue |
|
Pages |
50-60 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Nano-beam electron diffraction (NBED) is a method which can be applied to measure lattice strain and polarisation fields in strained layer heterostructures and transistors. To investigate precision, accuracy and spatial resolution of such measurements in dependence of properties of the specimen as well as electron optical parameters, simulations of NBED patterns are required which allow to predict the result of common disc-detection algorithms. In this paper we demonstrate by focusing on the detection of the central disc in crystalline silicon that such simulations require to take several experimental characteristics into account in order to obtain results which are comparable to those from experimental NBED patterns. These experimental characteristics are the background intensity, the presence of Poisson noise caused by electron statistics and blurring caused by inelastic scattering and by the transfer quality of the microscope camera. By means of these optimized simulations, different effects of specimen properties on disc detection – such as strain, surface morphology and compositional changes on the nanometer scale – are investigated and discussed in the context of misinterpretation in experimental NBED evaluations. It is shown that changes in surface morphology and chemical composition lead to measured shifts of the central disc in the NBED pattern of tens to hundreds of grad. These shifts are of the same order of magnitude or even larger than shifts that could be caused by an electric polarisation field in the range of MV/cm. (C) 2017 Elsevier B.V. All rights reserved. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000411170800006 |
Publication Date |
2017-05-03 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0304-3991 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.843 |
Times cited |
6 |
Open Access |
Not_Open_Access |
Notes |
; This work was supported by the German Research Foundation (DFG) under Contract No. R02057/11-1, R02057/4-2 and MU3660/1-1. ; |
Approved |
Most recent IF: 2.843 |
Call Number |
UA @ lucian @ c:irua:146725 |
Serial |
4792 |
Permanent link to this record |
|
|
|
Author |
Grieb, T.; Tewes, M.; Schowalter, M.; Müller-Caspary, K.; Krause, F.F.; Mehrtens, T.; Hartmann, J.-M.; Rosenauer, A. |
Title |
Quantitative HAADF STEM of SiGe in presence of amorphous surface layers from FIB preparation |
Type |
A1 Journal article |
Year |
2018 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
184 |
Issue |
B |
Pages |
29-36 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
<script type='text/javascript'>document.write(unpmarked('The chemical composition of four Si1-xGex layers grown on silicon was determined from quantitative scanning transmission electron microscopy (STEM). The chemical analysis was performed by a comparison of the high-angle annular dark field (HAADF) intensity with multislice simulations. It could be shown that amorphous surface layers originating from the preparation process by focused-ion beam (FIB) at 30 kV have a strong influence on the quantification: the local specimen thickness is overestimated by approximately a factor of two, and the germanium concentration is substantially underestimated. By means of simulations, the effect of amorphous surface layers on the HAADF intensity of crystalline silicon and germanium is investigated. Based on these simulations, a method is developed to analyze the experimental HAADF-STEM images by taking the influence of the amorphous layers into account which is done by a reduction of the intensities by multiplication with a constant factor. This suggested modified HAADF analysis gives germanium concentrations which are in agreement with the nominal values. The same TEM lamella was treated with low-voltage ion milling which removed the amorphous surface layers completely. The results from subsequent quantitative HAADF analyses are in agreement with the nominal concentrations which validates the applicability of the used frozen-lattice based multislice simulations to describe the HAADF scattering of Si1-xGex in STEM. (C) 2017 Elsevier B.V. All rights reserved.')); |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000417779800004 |
Publication Date |
2017-10-14 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0304-3991 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.843 |
Times cited |
7 |
Open Access |
Not_Open_Access |
Notes |
; This work was supported by the German Research Foundation (DFG) under Contract No. RO2057/11-1. ; |
Approved |
Most recent IF: 2.843 |
Call Number |
UA @ lucian @ c:irua:148500 |
Serial |
4893 |
Permanent link to this record |
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|
|
Author |
Grieb, T.; Krause, F.F.; Schowalter, M.; Zillmann, D.; Sellin, R.; Müller-Caspary, K.; Mahr, C.; Mehrtens, T.; Bimberg, D.; Rosenauer, A. |
Title |
Strain analysis from nano-beam electron diffraction : influence of specimen tilt and beam convergence |
Type |
A1 Journal article |
Year |
2018 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
190 |
Issue |
190 |
Pages |
45-57 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Strain analyses from experimental series of nano-beam electron diffraction (NBED) patterns in scanning transmission electron microscopy are performed for different specimen tilts. Simulations of NBED series are presented for which strain analysis gives results that are in accordance with experiment. This consequently allows to study the relation between measured strain and actual underlying strain. A two-tilt method which can be seen as lowest-order electron beam precession is suggested and experimentally implemented. Strain determination from NBED series with increasing beam convergence is performed in combination with the experimental realization of a probe-forming aperture with a cross inside. It is shown that using standard evaluation techniques, the influence of beam convergence on spatial resolution is lower than the influence of sharp rings around the diffraction disc which occur at interfaces and which are caused by the tails of the intensity distribution of the electron probe. (C) 2018 Elsevier B.V. All rights reserved. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000432868800006 |
Publication Date |
2018-04-12 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0304-3991 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.843 |
Times cited |
1 |
Open Access |
OpenAccess |
Notes |
; This work was supported by the German Research Foundation (DFG) under Contracts RO2057/11-1 and RO2057/12-1. ; |
Approved |
Most recent IF: 2.843 |
Call Number |
UA @ lucian @ c:irua:151454 |
Serial |
5041 |
Permanent link to this record |
|
|
|
Author |
Müller-Caspary, K.; Krause, F.F.; Winkler, F.; Béché, A.; Verbeeck, J.; Van Aert, S.; Rosenauer, A. |
Title |
Comparison of first moment STEM with conventional differential phase contrast and the dependence on electron dose |
Type |
A1 Journal article |
Year |
2019 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
203 |
Issue |
203 |
Pages |
95-104 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
This study addresses the comparison of scanning transmission electron microscopy (STEM) measurements of momentum transfers using the first moment approach and the established method that uses segmented annular detectors. Using an ultrafast pixelated detector to acquire four-dimensional, momentum-resolved STEM signals, both the first moment calculation and the calculation of the differential phase contrast (DPC) signals are done for the same experimental data. In particular, we investigate the ability to correct the segment-based signal to yield a suitable approximation of the first moment for cases beyond the weak phase object approximation. It is found that the measurement of momentum transfers using segmented detectors can approach the first moment measurement as close as 0.13 h/nm in terms of a root mean square (rms) difference in 10 nm thick SrTiO3 for a detector with 16 segments. This amounts to 35% of the rms of the momentum transfers. In addition, we present a statistical analysis of the precision of first moment STEM as a function of dose. For typical experimental settings with recent hardware such as a Medipix3 Merlin camera attached to a probe-corrected STEM, we find that the precision of the measurement of momentum transfers stagnates above certain doses. This means that other instabilities such as specimen drift or scan noise have to be taken into account seriously for measurements that target, e.g., the detection of bonding effects in the charge density. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000465021000013 |
Publication Date |
2018-12-30 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0304-3991 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.843 |
Times cited |
25 |
Open Access |
OpenAccess |
Notes |
; The direct electron detector (Medipix3 Merlin) was funded by the Hercules fund from the Flemish Government. K. Muller-Caspary acknowledges funding from the Initiative and Network Fund of the Helmholtz Association within the framework of the Helmholtz Young Investigator Group moreSTEM (VH-NG-1317) at Forschungszentrum Julich, Germany. F. F. Krause acknowledges funding from the Central Research Development Fund of the University of Bremen, Germany. This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (Grant Agreement No. 770887). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) and the Research Fund of the University of Antwerp. ; |
Approved |
Most recent IF: 2.843 |
Call Number |
UA @ admin @ c:irua:160213 |
Serial |
5242 |
Permanent link to this record |
|
|
|
Author |
de Backer, A.; Martinez, G.T.; Rosenauer, A.; Van Aert, S. |
Title |
Atom counting in HAADF STEM using a statistical model-based approach : methodology, possibilities, and inherent limitations |
Type |
A1 Journal article |
Year |
2013 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
134 |
Issue |
|
Pages |
23-33 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
In the present paper, a statistical model-based method to count the number of atoms of monotype crystalline nanostructures from high resolution high-angle annular dark-field (HAADF) scanning transmission electron microscopy (STEM) images is discussed in detail together with a thorough study on the possibilities and inherent limitations. In order to count the number of atoms, it is assumed that the total scattered intensity scales with the number of atoms per atom column. These intensities are quantitatively determined using model-based statistical parameter estimation theory. The distribution describing the probability that intensity values are generated by atomic columns containing a specific number of atoms is inferred on the basis of the experimental scattered intensities. Finally, the number of atoms per atom column is quantified using this estimated probability distribution. The number of atom columns available in the observed STEM image, the number of components in the estimated probability distribution, the width of the components of the probability distribution, and the typical shape of a criterion to assess the number of components in the probability distribution directly affect the accuracy and precision with which the number of atoms in a particular atom column can be estimated. It is shown that single atom sensitivity is feasible taking the latter aspects into consideration. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000324474900005 |
Publication Date |
2013-05-17 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.843 |
Times cited |
48 |
Open Access |
|
Notes |
FWO; Esteem2; FP 2007-2013; esteem2_jra2 |
Approved |
Most recent IF: 2.843; 2013 IF: 2.745 |
Call Number |
UA @ lucian @ c:irua:109916 |
Serial |
162 |
Permanent link to this record |
|
|
|
Author |
van den Broek, W.; Rosenauer, A.; Goris, B.; Martinez, G.T.; Bals, S.; Van Aert, S.; van Dyck, D. |
Title |
Correction of non-linear thickness effects in HAADF STEM electron tomography |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
116 |
Issue |
|
Pages |
8-12 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
Abstract |
In materials science, high angle annular dark field scanning transmission electron microscopy is often used for tomography at the nanometer scale. In this work, it is shown that a thickness dependent, non-linear damping of the recorded intensities occurs. This results in an underestimated intensity in the interior of reconstructions of homogeneous particles, which is known as the cupping artifact. In this paper, this non-linear effect is demonstrated in experimental images taken under common conditions and is reproduced with a numerical simulation. Furthermore, an analytical derivation shows that these non-linearities can be inverted if the imaging is done quantitatively, thus preventing cupping in the reconstruction. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000304473700002 |
Publication Date |
2012-03-09 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.843 |
Times cited |
67 |
Open Access |
|
Notes |
Fwo |
Approved |
Most recent IF: 2.843; 2012 IF: 2.470 |
Call Number |
UA @ lucian @ c:irua:96558 |
Serial |
518 |
Permanent link to this record |
|
|
|
Author |
Kruse, P.; Schowalter, M.; Lamoen, D.; Rosenauer, A.; Gerthsen, D. |
Title |
Determination of the mean inner potential in III-V semiconductors, Si and Ge by density functional theory and electron holography |
Type |
A1 Journal article |
Year |
2006 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
106 |
Issue |
2 |
Pages |
105-113 |
Keywords |
A1 Journal article; Electron Microscopy for Materials Science (EMAT); |
Abstract |
|
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000234535900005 |
Publication Date |
2005-07-29 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.843 |
Times cited |
50 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.843; 2006 IF: 1.706 |
Call Number |
UA @ lucian @ c:irua:56143 |
Serial |
678 |
Permanent link to this record |
|
|
|
Author |
Rosenauer, A.; Schowalter, M.; Titantah, J.T.; Lamoen, D. |
Title |
An emission-potential multislice approximation to simulate thermal diffuse scattering in high-resolution transmission electron microscopy |
Type |
A1 Journal article |
Year |
2008 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
108 |
Issue |
12 |
Pages |
1504-1513 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Thermal diffuse scattered electrons significantly contribute to high-resolution transmission electron microscopy images. Their intensity adds to the background and is peaked at positions of atomic columns. In this paper we suggest an approximation to simulate intensity of thermal diffuse scattered electrons in plane-wave illumination transmission electron microscopy using an emission-potential multislice algorithm which is computationally less intensive than the frozen lattice approximation or the mutual intensity approach. Intensity patterns are computed for Au and InSb for different crystal orientations. These results are compared with intensities from the frozen lattice approximation based on uncorrelated vibration of atoms as well as with the frozen phonon approximation for Au. The frozen phonon method uses a detailed phonon model based on force constants we computed by a density functional theory approach. The comparison shows that our suggested emission-potential method is in close agreement with both the frozen lattice and the frozen phonon approximations. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000260808300002 |
Publication Date |
2008-04-21 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.843 |
Times cited |
25 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.843; 2008 IF: 2.629 |
Call Number |
UA @ lucian @ c:irua:72919 |
Serial |
1033 |
Permanent link to this record |
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|
|
Author |
Krause, F.F.; Ahl, J.P.; Tytko, D.; Choi, P.P.; Egoavil, R.; Schowalter, M.; Mehrtens, T.; Müller-Caspary, K.; Verbeeck, J.; Raabe, D.; Hertkorn, J.; Engl, K.; Rosenauer, A. |
Title |
Homogeneity and composition of AlInGaN : a multiprobe nanostructure study |
Type |
A1 Journal article |
Year |
2015 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
156 |
Issue |
156 |
Pages |
29-36 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The electronic properties of quaternary AlInGaN devices significantly depend on the homogeneity of the alloy. The identification of compositional fluctuations or verification of random-alloy distribution is hence of grave importance. Here, a comprehensive multiprobe study of composition and compositional homogeneity is presented, investigating AlInGaN layers with indium concentrations ranging from 0 to 17 at% and aluminium concentrations between 0 and 39 at% employing high-angle annular dark field scanning electron microscopy (HAADF STEM), energy dispersive X-ray spectroscopy (EDX) and atom probe tomography (APT). EDX mappings reveal distributions of local concentrations which are in good agreement with random alloy atomic distributions. This was hence investigated with HAADF STEM by comparison with theoretical random alloy expectations using statistical tests. To validate the performance of these tests, HAADF STEM image simulations were carried out for the case of a random-alloy distribution of atoms and for the case of In-rich clusters with nanometer dimensions. The investigated samples, which were grown by metal-organic vapor phase epitaxy (MOVPE), were thereby found to be homogeneous on this nanometer scale. Analysis of reconstructions obtained from APT measurements yielded matching results. Though HAADF STEM only allows for the reduction of possible combinations of indium and aluminium concentrations to the proximity of isolines in the two-dimensional composition space. The observed ranges of composition are in good agreement with the EDX and APT results within the respective precisions. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000361001800006 |
Publication Date |
2015-04-26 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.843 |
Times cited |
11 |
Open Access |
|
Notes |
312483 Esteem2; esteem2_ta |
Approved |
Most recent IF: 2.843; 2015 IF: 2.436 |
Call Number |
c:irua:126965 c:irua:126965UA @ admin @ c:irua:126965 |
Serial |
1485 |
Permanent link to this record |
|
|
|
Author |
Verbeeck, J.; Sc hattschneider, P.; Rosenauer, A. |
Title |
Image simulation of high resolution energy filtered TEM images |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
109 |
Issue |
4 |
Pages |
350-360 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Inelastic image simulation software is presented, implementing the double channeling approximation which takes into account the combination of multiple elastic and single inelastic scattering in a crystal. The approach is described with a density matrix formalism. Two applications in high resolution energy filtered (EFTEM) transmission electron microscopy (TEM) images are presented: thickness-defocus maps for SrTiO3 and exit plane intensities for an (LaAlO3)3(SrTiO3)3 multilayer system. Both systems show a severe breakdown in direct interpretability which becomes worse for higher acceleration voltages, thicker samples and lower excitation edge energies. Since this effect already occurs in the exit plane intensity, it is a fundamental limit and image simulations in EFTEM are indispensable just as they are indispensable for elastic high resolution TEM images. |
Address |
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Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000265345400009 |
Publication Date |
2009-01-17 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.843 |
Times cited |
36 |
Open Access |
|
Notes |
Fwo; Esteem 026019 |
Approved |
Most recent IF: 2.843; 2009 IF: 2.067 |
Call Number |
UA @ lucian @ c:irua:77272UA @ admin @ c:irua:77272 |
Serial |
1552 |
Permanent link to this record |
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|
|
Author |
Van den Broek, W.; Rosenauer, A.; Van Aert, S.; Sijbers, J.; van Dyck, D. |
Title |
A memory efficient method for fully three-dimensional object reconstruction with HAADF STEM |
Type |
A1 Journal article |
Year |
2014 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
141 |
Issue |
|
Pages |
22-31 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
Abstract |
The conventional approach to object reconstruction through electron tomography is to reduce the three-dimensional problem to a series of independent two-dimensional slice-by-slice reconstructions. However, at atomic resolution the image of a single atom extends over many such slices and incorporating this image as prior knowledge in tomography or depth sectioning therefore requires a fully three-dimensional treatment. Unfortunately, the size of the three-dimensional projection operator scales highly unfavorably with object size and readily exceeds the available computer memory. In this paper, it is shown that for incoherent image formation the memory requirement can be reduced to the fundamental lower limit of the object size, both for tomography and depth sectioning. Furthermore, it is shown through multislice calculations that high angle annular dark field scanning transmission electron microscopy can be sufficiently incoherent for the reconstruction of single element nanocrystals, but that dynamical diffraction effects can cause classification problems if more than one element is present. (C) 2014 Elsevier B.V. All rights reserved. |
Address |
|
Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000335766600004 |
Publication Date |
2014-03-22 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.843 |
Times cited |
6 |
Open Access |
|
Notes |
ResearchFoundationFlanders(FWO;G.0393.11; G.0064.10;andG.0374.13); European Union Seventh Frame- workProgramme [FP7/2007-2013]under Grant agreement no. 312483 (ESTEEM2).; esteem2jra2; esteem2jra4 |
Approved |
Most recent IF: 2.843; 2014 IF: 2.436 |
Call Number |
UA @ lucian @ c:irua:117650 |
Serial |
1992 |
Permanent link to this record |
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|
|
Author |
Martinez, G.T.; Rosenauer, A.; de Backer, A.; Verbeeck, J.; Van Aert, S. |
Title |
Quantitative composition determination at the atomic level using model-based high-angle annular dark field scanning transmission electron microscopy |
Type |
A1 Journal article |
Year |
2014 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
137 |
Issue |
|
Pages |
12-19 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
High angle annular dark field scanning transmission electron microscopy (HAADF STEM) images provide sample information which is sensitive to the chemical composition. The image intensities indeed scale with the mean atomic number Z. To some extent, chemically different atomic column types can therefore be visually distinguished. However, in order to quantify the atomic column composition with high accuracy and precision, model-based methods are necessary. Therefore, an empirical incoherent parametric imaging model can be used of which the unknown parameters are determined using statistical parameter estimation theory (Van Aert et al., 2009, [1]). In this paper, it will be shown how this method can be combined with frozen lattice multislice simulations in order to evolve from a relative toward an absolute quantification of the composition of single atomic columns with mixed atom types. Furthermore, the validity of the model assumptions are explored and discussed. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000331092200003 |
Publication Date |
2013-11-09 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.843 |
Times cited |
74 |
Open Access |
|
Notes |
FWO; FP7; ERC Countatoms; ESTEEM2; esteem2_ta |
Approved |
Most recent IF: 2.843; 2014 IF: 2.436 |
Call Number |
UA @ lucian @ c:irua:111579UA @ admin @ c:irua:111579 |
Serial |
2749 |
Permanent link to this record |