| Records |
| 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 |
|
| Corporate Author |
|
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 |
Schowalter, M.; Rosenauer, A.; Lamoen, D.; Kruse, P.; Gerthsen, D. |
| Title |
Ab initio computation of the mean inner Coulomb potential of technological important semiconductors |
Type |
A1 Journal article |
| Year |
2005 |
Publication |
|
Abbreviated Journal |
|
| Volume |
1007 |
Issue |
|
Pages |
233-236 |
| Keywords |
A1 Journal article; Electron Microscopy for Materials Science (EMAT); |
| Abstract |
|
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Berlin |
Editor |
|
| Language |
|
Wos |
|
Publication Date |
0000-00-00 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0930-8989 |
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:72915 |
Serial |
32 |
| Permanent link to this record |
| |
|
| |
| 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 |
|
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos |
000238914500031 |
Publication Date |
2006-06-19 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| 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 |
| |
|
| |
| 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 |
Mueller, K.; Krause, F.F.; Béché, A.; Schowalter, M.; Galioit, V.; Loeffler, S.; Verbeeck, J.; Zweck, J.; Schattschneider, P.; Rosenauer, A. |
| Title |
Atomic electric fields revealed by a quantum mechanical approach to electron picodiffraction |
Type |
A1 Journal article |
| Year |
2014 |
Publication |
Nature communications |
Abbreviated Journal |
Nat Commun |
| Volume |
5 |
Issue |
|
Pages |
5653 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
By focusing electrons on probes with a diameter of 50 pm, aberration-corrected scanning transmission electron microscopy (STEM) is currently crossing the border to probing subatomic details. A major challenge is the measurement of atomic electric fields using differential phase contrast (DPC) microscopy, traditionally exploiting the concept of a field- induced shift of diffraction patterns. Here we present a simplified quantum theoretical interpretation of DPC. This enables us to calculate the momentum transferred to the STEM probe from diffracted intensities recorded on a pixel array instead of conventional segmented bright- field detectors. The methodical development yielding atomic electric field, charge and electron density is performed using simulations for binary GaN as an ideal model system. We then present a detailed experimental study of SrTiO3 yielding atomic electric fields, validated by comprehensive simulations. With this interpretation and upgraded instrumentation, STEM is capable of quantifying atomic electric fields and high-contrast imaging of light atoms. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000347227700003 |
Publication Date |
2014-12-15 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2041-1723; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
12.124 |
Times cited |
197 |
Open Access |
|
| Notes |
246791 COUNTATOMS; 278510 VORTEX; Hercules; 312483 ESTEEM2; esteem2ta; ECASJO; |
Approved |
Most recent IF: 12.124; 2014 IF: 11.470 |
| Call Number |
UA @ lucian @ c:irua:122835UA @ admin @ c:irua:122835 |
Serial |
166 |
| Permanent link to this record |
| |
|
| |
| 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 |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos |
000247625700034 |
Publication Date |
2007-06-20 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| 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 |
| |
|
| |
| Author |
Schowalter, M.; Rosenauer, A.; Titantah, J.T.; Lamoen, D. |
| Title |
Calculation of Debye-Waller temperature factors for GaAs |
Type |
A1 Journal article |
| Year |
2008 |
Publication |
Springer proceedings in physics |
Abbreviated Journal |
|
| Volume |
120 |
Issue |
|
Pages |
195-198 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
|
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Berlin |
Editor |
|
| Language |
|
Wos |
|
Publication Date |
0000-00-00 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0930-8989 |
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:73966 |
Serial |
266 |
| Permanent link to this record |
| |
|
| |
| 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 |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Copenhagen |
Editor |
|
| Language |
|
Wos |
000261799500002 |
Publication Date |
2008-11-05 |
| Series Editor |
|
Series Title |
|
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 |
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 |
|
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 |
| |
|
| |
| 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 |
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 |
|
| Corporate Author |
|
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 |
| |
|
| |
| 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 |
Martinez, G.T.; de Backer, A.; Rosenauer, A.; Verbeeck, J.; Van Aert, S. |
| Title |
The effect of probe inaccuracies on the quantitative model-based analysis of high angle annular dark field scanning transmission electron microscopy images |
Type |
A1 Journal article |
| Year |
2014 |
Publication |
Micron |
Abbreviated Journal |
Micron |
| Volume |
63 |
Issue |
|
Pages |
57-63 |
| Keywords |
A1 Journal article; Engineering Management (ENM); Electron microscopy for materials research (EMAT) |
| Abstract |
Quantitative structural and chemical information can be obtained from high angle annular dark field scanning transmission electron microscopy (HAADF STEM) images when using statistical parameter estimation theory. In this approach, we assume an empirical parameterized imaging model for which the total scattered intensities of the atomic columns are estimated. These intensities can be related to the material structure or composition. Since the experimental probe profile is assumed to be known in the description of the imaging model, we will explore how the uncertainties in the probe profile affect the estimation of the total scattered intensities. Using multislice image simulations, we analyze this effect for Cs corrected and non-Cs corrected microscopes as a function of inaccuracies in cylindrically symmetric aberrations, such as defocus and spherical aberration of third and fifth order, and non-cylindrically symmetric aberrations, such as 2-fold and 3-fold astigmatism and coma. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Oxford |
Editor |
|
| Language |
|
Wos |
000338402500011 |
Publication Date |
2014-01-02 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0968-4328; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.98 |
Times cited |
25 |
Open Access |
|
| Notes |
FWO (G.0393.11; G.0064.10; G.0374.13; G.0044.13); European Research Council under the 7th Framework Program (FP7); ERC GrantNo. 246791-COUNTATOMS and ERC Starting Grant No. 278510-VORTEX. A.R. thanks the DFG under contract number RO2057/8-1.The research leading to these results has received funding fromthe European Union 7th Framework Programme [FP7/2007-2013]under grant agreement no. 312483 (ESTEEM2).; esteem2ta ECASJO; |
Approved |
Most recent IF: 1.98; 2014 IF: 1.988 |
| Call Number |
UA @ lucian @ c:irua:113857UA @ admin @ c:irua:113857 |
Serial |
831 |
| Permanent link to this record |
| |
|
| |
| Author |
Titantah, J.T.; Lamoen, D.; Schowalter, M.; Rosenauer, A. |
| Title |
Effect of temperature on the 002 electron structure factor and its consequence for the quantification of ternary and quaternary III-V crystals |
Type |
A1 Journal article |
| Year |
2008 |
Publication |
Springer proceedings in physics |
Abbreviated Journal |
|
| Volume |
120 |
Issue |
|
Pages |
189-194 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
|
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Berlin |
Editor |
|
| Language |
|
Wos |
|
Publication Date |
0000-00-00 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0930-8989 |
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:73965 |
Serial |
839 |
| 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 |
| |
|
| |
| Author |
Rosenauer, A.; Schowalter, M.; Glas, F.; Lamoen, D. |
| Title |
First-principles calculations of 002 structure factors for electron scattering in strained InxGa1-xAs |
Type |
A1 Journal article |
| Year |
2005 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
72 |
Issue |
8 |
Pages |
1-10 |
| Keywords |
A1 Journal article; Electron Microscopy for Materials Science (EMAT); |
| Abstract |
This work provides values of electron scattering 002 structure factors for InxGa1-xAs as a function of the In concentration x=0 to 1. These results allow accurate compositional analysis of pseudomorphically grown InxGa1-xAs/GaAs layers by transmission electron microscopy methods relying on the chemical sensitivity of the (002) beam. The calculations go beyond the limits of the isolated atom approximation, because they take into account charge redistribution effects between atomic sites in the crystal, strain, and static atomic displacements. The computations were performed by the full potential linearized augmented plane-wave method using a generalized gradient approximation for the exchange and correlation part of the potential. The calculations of strained InxGa1-xAs correspond to the strain state in specimens with large, small, and intermediate thickness in the electron beam direction. Additionally, the effect of static atomic displacements is taken into account. All results are listed in a parameterized form. The calculated 002 structure factor vanishes at an In concentration of 16.4%. This value is in a good agreement with previously reported experimental measurements. Hence, our results are a significant improvement with respect to the isolated atom approximation which is conventionally applied in transmission electron microscopy simulations, and which predicts a value of 22.5%. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
| Language |
|
Wos |
000231564600106 |
Publication Date |
2005-08-12 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| 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 |
42 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.836; 2005 IF: 3.185 |
| Call Number |
UA @ lucian @ c:irua:54918 |
Serial |
1201 |
| Permanent link to this record |
| |
|
| |
| Author |
Rosenauer, A.; Schowalter, M.; Glas, F.; Lamoen, D. |
| Title |
First-principles calculations of 002 structure factors for electron scattering in strained InxGa1-xAs |
Type |
A1 Journal article |
| Year |
2005 |
Publication |
|
Abbreviated Journal |
|
| Volume |
107 |
Issue |
|
Pages |
151-154 |
| Keywords |
A1 Journal article; Electron Microscopy for Materials Science (EMAT); |
| Abstract |
|
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Berlin |
Editor |
|
| Language |
|
Wos |
|
Publication Date |
0000-00-00 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0930-8989 |
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:72916 |
Serial |
1202 |
| Permanent link to this record |
| |
|
| |
| 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 |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos |
000225300600037 |
Publication Date |
2004-11-24 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| 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 |
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 |
| |
|
| |
| 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 |
|
| Corporate Author |
|
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 |
| |
|
| |
| 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 |
|
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
London |
Editor |
|
| Language |
|
Wos |
000249890700003 |
Publication Date |
2007-09-04 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| 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 |
| |
|
| |
| 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 |
|
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos |
000228901600121 |
Publication Date |
2005-04-06 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| 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 |
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 |
| |
|
| |
| 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 |
|
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 |
| |
|
| |
| 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 |
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 |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos |
000341188700073 |
Publication Date |
2014-08-14 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
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 |
| |
|
| |
| 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. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
|
Publication Date |
0000-00-00 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0-7503-0979-2 |
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:95118 |
Serial |
2710 |
| Permanent link to this record |
| |
|
| |
| Author |
Van Aert, S.; de Backer, A.; Martinez, G.T.; Goris, B.; Bals, S.; Van Tendeloo, G.; Rosenauer, A. |
| Title |
Procedure to count atoms with trustworthy single-atom sensitivity |
Type |
A1 Journal article |
| Year |
2013 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
87 |
Issue |
6 |
Pages |
064107-6 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
We report a method to reliably count the number of atoms from high-angle annular dark field scanning transmission electron microscopy images. A model-based analysis of the experimental images is used to measure scattering cross sections at the atomic level. The high sensitivity of these measurements in combination with a thorough statistical analysis enables us to count atoms with single-atom sensitivity. The validity of the results is confirmed by means of detailed image simulations. We will show that the method can be applied to nanocrystals of arbitrary shape, size, and atom type without the need for a priori knowledge about the atomic structure. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000315144700006 |
Publication Date |
2013-02-20 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| 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 |
106 |
Open Access |
|
| Notes |
FWO; 262348 ESMI; 312483 ESTEEM2;246791 COUNTATOMS; Hercules 3; esteem2_jra2 |
Approved |
Most recent IF: 3.836; 2013 IF: 3.664 |
| Call Number |
UA @ lucian @ c:irua:105674 |
Serial |
2718 |
| Permanent link to this record |
| |
|
| |
| 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 |
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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 |
000331092200003 |
Publication Date |
2013-11-09 |
| 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 |
74 |
Open Access |
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| 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 |
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| 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 |
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Wos |
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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 |
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Series Issue |
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Edition |
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| ISSN |
1742-6596; |
ISBN |
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Additional Links |
UA library record |
| Impact Factor |
|
Times cited |
|
Open Access |
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| Notes |
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Approved |
Most recent IF: NA |
| Call Number |
UA @ lucian @ c:irua:85761 |
Serial |
2855 |
| 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 |
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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 |
000266787900005 |
Publication Date |
2009-03-23 |
| 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 |
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 |
