Records |
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 |
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Editor |
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Language |
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Wos |
000461067700007 |
Publication Date |
2019-03-11 |
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 |
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 |
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. |
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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 |
|
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 |
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. |
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Corporate Author |
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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 |
000465021000013 |
Publication Date |
2018-12-30 |
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 |
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 |
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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) |
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 |
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Publication Date |
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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 |
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ISBN |
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Additional Links |
UA library record |
Impact Factor |
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Times cited |
|
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 |
Piscopiello, E.; Rosenauer, A.; Passaseo, A.; Montoya Rossi, E.H.; Van Tendeloo, G. |
Title |
Segregation in InxGa1-xAs/GaAs Stranski-Krastanow layers grown by metal-organic chemical vapour deposition |
Type |
A1 Journal article |
Year |
2005 |
Publication |
Philosophical magazine |
Abbreviated Journal |
Philos Mag |
Volume |
85 |
Issue |
32 |
Pages |
3857-3870 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
|
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
London |
Editor |
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Language |
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Wos |
000233171500007 |
Publication Date |
2005-11-10 |
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 |
1478-6435;1478-6443; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.505 |
Times cited |
11 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 1.505; 2005 IF: 1.470 |
Call Number |
UA @ lucian @ c:irua:59054 |
Serial |
2961 |
Permanent link to this record |
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Author |
Titantah, J.T.; Lamoen, D.; Schowalter, M.; Rosenauer, A. |
Title |
Temperature effect on the 002 structure factor of ternary Ga1-xInxAs crystals |
Type |
A1 Journal article |
Year |
2007 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
76 |
Issue |
7 |
Pages |
073303,1-4 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
|
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Lancaster, Pa |
Editor |
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Language |
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Wos |
000249155300011 |
Publication Date |
2007-08-03 |
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 |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
3 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.836; 2007 IF: 3.172 |
Call Number |
UA @ lucian @ c:irua:66116 |
Serial |
3499 |
Permanent link to this record |
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Author |
Rossi, E.H.M.; Van Tendeloo, G.; Rosenauer, A. |
Title |
Influence of strain, specimen orientation and background estimation on composition evaluation of InAs/GaAs by TEM |
Type |
A1 Journal article |
Year |
2007 |
Publication |
Philosophical magazine |
Abbreviated Journal |
Philos Mag |
Volume |
87 |
Issue |
29 |
Pages |
4461-4473 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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 |
London |
Editor |
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Language |
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Wos |
000249890700003 |
Publication Date |
2007-09-04 |
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 |
1478-6435;1478-6443; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.505 |
Times cited |
1 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 1.505; 2007 IF: 1.486 |
Call Number |
UA @ lucian @ c:irua:66612 |
Serial |
1638 |
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 |
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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 |
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 |
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Series Issue |
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Edition |
|
ISSN |
0021-8979; |
ISBN |
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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 |
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 |
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Publisher |
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Place of Publication |
Copenhagen |
Editor |
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Language |
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Wos |
000261799500002 |
Publication Date |
2008-11-05 |
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 |
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 |
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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 |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
000260808300002 |
Publication Date |
2008-04-21 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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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 |
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 |
Titantah, J.T.; Lamoen, D.; Schowalter, M.; Rosenauer, A. |
Title |
Size effects and strain state of Ga1-xInxAs/GaAs multiple quantum wells: Monte Carlo study |
Type |
A1 Journal article |
Year |
2008 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
78 |
Issue |
16 |
Pages |
165326,1-165326,7 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The effect of the size of the GaAs barrier and the Ga1−xInxAs well on the structural properties of a Ga1−xInxAs/GaAs multiple quantum well structure is investigated using the Metropolis Monte Carlo approach based on a well-parametrized Tersoff potential. It is found that within the well the Ga-As and In-As bond lengths undergo contractions whose magnitude increases with increasing In content in sharp contrast with bond-length variations in the bulk Ga1−xInxAs systems. For fixed barrier size and In content, the contraction of the bonds is also found to increase with increasing size of the well. Using the local atomic structure of the heterostructures, a more local analysis of the strain state of the systems is given and comparison with the prediction of macroscopic continuum elasticity theory shows deviations from the latter. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Lancaster, Pa |
Editor |
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Language |
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Wos |
000260574500084 |
Publication Date |
2008-10-28 |
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 |
5 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.836; 2008 IF: 3.322 |
Call Number |
UA @ lucian @ c:irua:72920 |
Serial |
3036 |
Permanent link to this record |
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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 |
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Place of Publication |
Copenhagen |
Editor |
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Language |
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Wos |
000264927100006 |
Publication Date |
2009-03-12 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
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 |
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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 |
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Publisher |
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Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
000265345400009 |
Publication Date |
2009-01-17 |
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 |
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 |
Müller, K.; Schowalter, M.; Jansen, J.; Tsuda, K.; Titantah, J.; Lamoen, D.; Rosenauer, A. |
Title |
Refinement of the 200 structure factor for GaAs using parallel and convergent beam electron nanodiffraction data |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
109 |
Issue |
7 |
Pages |
802-814 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
We present a new method to measure structure factors from electron spot diffraction patterns recorded under almost parallel illumination in transmission electron microscopes. Bloch wave refinement routines have been developed to refine the crystal thickness, its orientation and structure factors by comparison of experimentally recorded and calculated intensities. Our method requires a modicum of computational effort, making it suitable for contemporary personal computers. Frozen lattice and Bloch wave simulations of GaAs diffraction patterns are used to derive optimised experimental conditions. Systematic errors are estimated from the application of the method to simulated diffraction patterns and rules for the recognition of physically reasonable initial refinement conditions are derived. The method is applied to the measurement of the 200 structure factor for GaAs. We found that the influence of inelastically scattered electrons is negligible. Additionally, we measured the 200 structure factor from zero loss filtered two-dimensional convergent beam electron diffraction patterns. The precision of both methods is found to be comparable and the results agree well with each other. A deviation of more than 20% from isolated atom scattering data is observed, whereas close agreement is found with structure factors obtained from density functional theory [A. Rosenauer, M. Schowalter, F. Glas, D. Lamoen, Phys. Rev. B 72 (2005), 085326-1], which account for the redistribution of electrons due to chemical bonding via modified atomic scattering amplitudes. |
Address |
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Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000266787900005 |
Publication Date |
2009-03-23 |
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 |
Fwo; G.0425.05; Esteem; Ant 200611271505 |
Approved |
Most recent IF: 2.843; 2009 IF: 2.067 |
Call Number |
UA @ lucian @ c:irua:77361 |
Serial |
2856 |
Permanent link to this record |
|
|
|
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 |
|
Publisher |
|
Place of Publication |
Oxford |
Editor |
|
Language |
|
Wos |
000268429000025 |
Publication Date |
2009-05-11 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
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 |
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 |
|
Corporate Author |
|
Thesis |
|
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 |
|
|
|
Author |
Titantah, J.T.; Lamoen, D.; Schowalter, M.; Rosenauer, A. |
Title |
Ab initio based atomic scattering amplitudes and {002} electron structure factors of InxGa1-xAs/GaAs quantum wells |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Journal of physics : conference series |
Abbreviated Journal |
|
Volume |
209 |
Issue |
1 |
Pages |
012040,1-012040,6 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The atomic scattering amplitudes of the various atoms of the systems Ga1−xInxAs, GaAs1−xNx and InAs1−xNx are calculated using the density functional theory (DFT) approach. The scattering amplitudes of N, Ga, As and In in the model systems are compared with the frequently used Doyle and Turner values. Deviation from the latter values is found for small scattering vectors (s<0.3Å−1) and for these scattering vectors dependence on the orientation of the scattering vector and the chemical environment is reported. We suggest a parametrization of these modified scattering amplitudes (MASAs) for small scattering vectors (s<1.0Å−1). The MASAs are exploited within zero pressure classical Metropolis Monte Carlo (MC), finite temperature calculations to investigate the effect of quantum well size on the electron {002} structure factor (SF) of Ga1−xInxAs quantum wells. |
Address |
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Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
Bristol |
Editor |
|
Language |
|
Wos |
000283739100040 |
Publication Date |
2010-02-27 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1742-6596; |
ISBN |
|
Additional Links |
UA library record; WoS full record |
Impact Factor |
|
Times cited |
|
Open Access |
|
Notes |
|
Approved |
Most recent IF: NA |
Call Number |
UA @ lucian @ c:irua:85760 |
Serial |
28 |
Permanent link to this record |
|
|
|
Author |
Müller, K.; Schowalter, M.; Rosenauer, A.; Jansen, J.; Tsuda, K.; Titantah, J.T.; Lamoen, D. |
Title |
Refinement of chemically sensitive structure factors using parallel and convergent beam electron nanodiffraction |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Journal of physics : conference series |
Abbreviated Journal |
|
Volume |
209 |
Issue |
1 |
Pages |
012025-012025,4 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
We introduce a new method to measure structure factors from parallel beam electron diffraction (PBED) patterns. Bloch wave refinement routines were developed which can minimise the difference between simulated and experimental Bragg intensities via variation of structure factors, Debye parameters, specimen thickness and -orientation. Due to plane wave illumination, the PBED refinement is highly efficient not only in computational respect, but also concerning the experimental effort since energy filtering is shown to have no significant effect on the refinement results. The PBED method was applied to simulated GaAs diffraction patterns to derive systematic errors and rules for the identification of plausible refinement results. The evaluation of experimental GaAs PBED patterns yields a 200 X-ray structure factor of -6.33±0.14. Additionally, we obtained -6.35±0.13 from two-dimensional convergent beam electron diffraction refinements. Both results confirm density functional theory calculations published by Rosenauer et al. and indicate the inaccuracy of isolated atom scattering data, which is crucial e.g. for the composition evaluation by lattice fringe analysis. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Bristol |
Editor |
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Language |
|
Wos |
|
Publication Date |
2010-02-27 |
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 |
1742-6596; |
ISBN |
|
Additional Links |
UA library record |
Impact Factor |
|
Times cited |
|
Open Access |
|
Notes |
|
Approved |
Most recent IF: NA |
Call Number |
UA @ lucian @ c:irua:85761 |
Serial |
2855 |
Permanent link to this record |
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|
|
Author |
Verbeeck, J.; Van Aert, S.; Zhang, L.; Haiyan, T.; Schattschneider, P.; Rosenauer, A. |
Title |
Computational aspects in quantitative EELS |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Microscopy and microanalysis |
Abbreviated Journal |
Microsc Microanal |
Volume |
16 |
Issue |
S:2 |
Pages |
240-241 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
|
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Cambridge, Mass. |
Editor |
|
Language |
|
Wos |
|
Publication Date |
2010-08-26 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1431-9276;1435-8115; |
ISBN |
|
Additional Links |
UA library record |
Impact Factor |
1.891 |
Times cited |
|
Open Access |
|
Notes |
|
Approved |
Most recent IF: 1.891; 2010 IF: 3.259 |
Call Number |
UA @ lucian @ c:irua:96556UA @ admin @ c:irua:96556 |
Serial |
454 |
Permanent link to this record |
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|
|
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 |
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Corporate Author |
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Thesis |
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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 |