Records |
Author |
Turner, S.; Lazar, S.; Freitag, B.; Egoavil, R.; Verbeeck, J.; Put, S.; Strauven, Y.; Van Tendeloo, G. |
Title |
High resolution mapping of surface reduction in ceria nanoparticles |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Nanoscale |
Abbreviated Journal |
Nanoscale |
Volume |
3 |
Issue |
8 |
Pages |
3385-3390 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Surface reduction of ceria nano octahedra with predominant {111} and {100} type surfaces is studied using a combination of aberration-corrected Transmission Electron Microscopy (TEM) and spatially resolved electron energy-loss spectroscopy (EELS) at high energy resolution and atomic spatial resolution. The valency of cerium ions at the surface of the nanoparticles is mapped using the fine structure of the Ce M4,5 edge as a fingerprint. The valency of the surface cerium ions is found to change from 4+ to 3+ owing to oxygen deficiency (vacancies) close to the surface. The thickness of this Ce3+ shell is measured using atomic-resolution Scanning Transmission Electron Microscopy (STEM)-EELS mapping over a {111} surface (the predominant facet for this ceria morphology), {111} type surface island steps and {100} terminating planes. For the {111} facets and for {111} surface islands, the reduction shell is found to extend over a single fully reduced surface plane and 12 underlying mixed valency planes. For the {100} facets the reduction shell extends over a larger area of 56 oxygen vacancy-rich planes. This finding provides a plausible explanation for the higher catalytic activity of the {100} surface facets in ceria. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
Cambridge |
Editor |
|
Language |
|
Wos |
000293521700057 |
Publication Date |
2011-06-30 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2040-3364;2040-3372; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
7.367 |
Times cited |
127 |
Open Access |
|
Notes |
Fwo |
Approved |
Most recent IF: 7.367; 2011 IF: 5.914 |
Call Number |
UA @ lucian @ c:irua:90361UA @ admin @ c:irua:90361 |
Serial |
1458 |
Permanent link to this record |
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|
|
Author |
Molina, L.; Tan, H.; Biermans, E.; Batenburg, K.J.; Verbeeck, J.; Bals, S.; Van Tendeloo, G. |
Title |
Barrier efficiency of sponge-like La2Zr2O7 buffer layers for YBCO-coated conductors |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Superconductor science and technology |
Abbreviated Journal |
Supercond Sci Tech |
Volume |
24 |
Issue |
6 |
Pages |
065019-065019,8 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
Abstract |
Solution derived La2Zr2O7 films have drawn much attention for potential applications as thermal barriers or low-cost buffer layers for coated conductor technology. Annealing and coating parameters strongly affect the microstructure of La2Zr2O7, but different film processing methods can yield similar microstructural features such as nanovoids and nanometer-sized La2Zr2O7 grains. Nanoporosity is a typical feature found in such films and the implications for the functionality of the films are investigated by a combination of scanning transmission electron microscopy (STEM), electron energy-loss spectroscopy (EELS) and quantitative electron tomography. Chemical solution based La2Zr2O7 films deposited on flexible Ni5 at.%W substrates with a {100}lang001rang biaxial texture were prepared for an in-depth characterization. A sponge-like structure composed of nanometer-sized voids is revealed by high-angle annular dark-field scanning transmission electron microscopy in combination with electron tomography. A three-dimensional quantification of nanovoids in the La2Zr2O7 film is obtained on a local scale. Mostly non-interconnected highly faceted nanovoids compromise more than one-fifth of the investigated sample volume. The diffusion barrier efficiency of a 170 nm thick La2Zr2O7 film is investigated by STEM-EELS, yielding a 1.8 ± 0.2 nm oxide layer beyond which no significant nickel diffusion can be detected and intermixing is observed. This is of particular significance for the functionality of YBa2Cu3O7 − δ coated conductor architectures based on solution derived La2Zr2O7 films as diffusion barriers. |
Address |
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Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
Bristol |
Editor |
|
Language |
|
Wos |
000290472900021 |
Publication Date |
2011-04-20 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0953-2048;1361-6668; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.878 |
Times cited |
31 |
Open Access |
|
Notes |
Esteem 026019; Fwo |
Approved |
Most recent IF: 2.878; 2011 IF: 2.662 |
Call Number |
UA @ lucian @ c:irua:88639UA @ admin @ c:irua:88639 |
Serial |
221 |
Permanent link to this record |
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|
|
Author |
Boschker, H.; Huijben, M.; Vailinois, A.; Verbeeck, J.; Van Aert, S.; Luysberg, M.; Bals, S.; Van Tendeloo, G.; Houwman, E.P.; Koster, G.; Blank, D.H.A.; Rijnders, G. |
Title |
Optimized fabrication of high-quality La0.67Sr0.33MnO3 thin films considering all essential characteristics |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Journal of physics: D: applied physics |
Abbreviated Journal |
J Phys D Appl Phys |
Volume |
44 |
Issue |
20 |
Pages |
205001-205001,9 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
In this paper, an overview of the fabrication and properties of high-quality La0.67Sr0.33MnO3 (LSMO) thin films is given. A high-quality LSMO film combines a smooth surface morphology with a large magnetization and a small residual resistivity, while avoiding precipitates and surface segregation. In the literature, typically only a few of these issues are adressed. We therefore present a thorough characterization of our films, which were grown by pulsed laser deposition. The films were characterized with reflection high energy electron diffraction, atomic force microscopy, x-ray diffraction, magnetization and transport measurements, x-ray photoelectron spectroscopy and scanning transmission electron microscopy. The films have a saturation magnetization of 4.0 µB/Mn, a Curie temperature of 350 K and a residual resistivity of 60 µΩ cm. These results indicate that high-quality films, combining both large magnetization and small residual resistivity, were realized. A comparison between different samples presented in the literature shows that focussing on a single property is insufficient for the optimization of the deposition process. For high-quality films, all properties have to be adressed. For LSMO devices, the thin-film quality is crucial for the device performance. Therefore, this research is important for the application of LSMO in devices. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
London |
Editor |
|
Language |
|
Wos |
000290150900001 |
Publication Date |
2011-04-29 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0022-3727;1361-6463; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.588 |
Times cited |
99 |
Open Access |
|
Notes |
This research was financially supported by the Dutch Science Foundation, by NanoNed, a nanotechnology program of the Dutch Ministry of Economic Affairs, and by the NanOxide program of the European Science Foundation. This work is supported in part by the Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering, under contract DE-AC02-76SF00515. |
Approved |
Most recent IF: 2.588; 2011 IF: 2.544 |
Call Number |
UA @ lucian @ c:irua:89557UA @ admin @ c:irua:89557 |
Serial |
2491 |
Permanent link to this record |
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|
|
Author |
Eckert, M.; Mortet, V.; Zhang, L.; Neyts, E.; Verbeeck, J.; Haenen, ken; Bogaerts, A. |
Title |
Theoretical investigation of grain size tuning during prolonged bias-enhanced nucleation |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
Volume |
23 |
Issue |
6 |
Pages |
1414-1423 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
In this paper, the effects of prolonged bias-enhanced nucleation (prolonged BEN) on the growth mechanisms of diamond are investigated by molecular dynamics (MD) and combined MD-Metropolis Monte Carlo (MD-MMC) simulations. First, cumulative impacts of CxHy+ and Hx+ on an a-C:H/nanodiamond composite were simulated; second, nonconsecutive impacts of the dominant ions were simulated in order to understand the observed phenomena in more detail. As stated in the existing literature, the growth of diamond structures during prolonged BEN is a process that takes place below the surface of the growing film. The investigation of the penetration behavior of CxHy+ and Hx+ species shows that the carbon-containing ions remain trapped within this amorphous phase where they dominate mechanisms like precipitation of sp3 carbon clusters. The H+ ions, however, penetrate into the crystalline phase at high bias voltages (>100 V), destroying the perfect diamond structure. The experimentally measured reduction of grain sizes at high bias voltage, reported in the literature, might thus be related to penetrating H+ ions. Furthermore, the CxHy+ ions are found to be the most efficient sputtering agents, preventing the build up of defective material. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
Language |
|
Wos |
000288291400011 |
Publication Date |
2011-02-23 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0897-4756;1520-5002; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
9.466 |
Times cited |
9 |
Open Access |
|
Notes |
Iwt; Fwo; Esteem 026019; Iap |
Approved |
Most recent IF: 9.466; 2011 IF: 7.286 |
Call Number |
UA @ lucian @ c:irua:87642 |
Serial |
3605 |
Permanent link to this record |
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|
|
Author |
Boullay, P.; David, A.; Sheets, W.C.; Lüders, U.; Prellier, W.; Tan, H.; Verbeeck, J.; Van Tendeloo, G.; Gatel, C.; Vincze, G.; Radi, Z. |
Title |
Microstructure and interface studies of LaVO3/SrVO3 superlattices |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
83 |
Issue |
12 |
Pages |
125403-125403,6 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The structure and interface characteristics of (LaVO3)6m(SrVO3)m superlattices deposited on a (100)-SrTiO3 substrate were studied using transmission electron microscopy (TEM). Cross-section TEM studies revealed that both LaVO3 (LVO) and SrVO3 (SVO) layers are good single-crystal quality and epitaxially grown with respect to the substrate. It is evidenced that LVO layers are made of two orientational variants of a distorted perovskite compatible with bulk LaVO3, while SVO layers suffers from a tetragonal distortion due to the substrate-induced stain. Electron energy loss spectroscopy investigations indicate changes in the fine structure of the V L23 edge, related to a valence change between the LaVO3 and the SrVO3 layers. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
|
Editor |
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Language |
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Wos |
000288160300006 |
Publication Date |
2011-03-09 |
Series Editor |
|
Series Title |
|
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 |
26 |
Open Access |
|
Notes |
Fwo; Esteem 026019 |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
Call Number |
UA @ lucian @ c:irua:88648UA @ admin @ c:irua:88648 |
Serial |
2054 |
Permanent link to this record |
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Author |
Bertoni, G.; Verbeeck, J.; Brosens, F. |
Title |
Fitting the momentum dependent loss function in EELS |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Microscopy research and technique |
Abbreviated Journal |
Microsc Res Techniq |
Volume |
74 |
Issue |
3 |
Pages |
212-218 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Theory of quantum systems and complex systems |
Abstract |
Momentum dependent inelastic plasmon scattering can be measured by electron energy loss in a transmission electron microscope. From energy filtered diffraction, the characteristic angle of scattering and the cutoff angle are measured, using a thin film of aluminum as a model test. Rather than deconvolving the data (as done in previous works), a fitting technique is used to extract the loss function from angular resolved spectra, starting from a simple model simulation. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000288095200002 |
Publication Date |
2010-07-06 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1059-910X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.147 |
Times cited |
6 |
Open Access |
|
Notes |
Fwo; Esteem; Iap; Goa |
Approved |
Most recent IF: 1.147; 2011 IF: 1.792 |
Call Number |
UA @ lucian @ c:irua:88782UA @ admin @ c:irua:88782 |
Serial |
1222 |
Permanent link to this record |
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|
Author |
Li, Y.; Tan, H.; Yang, X.-Y.; Goris, B.; Verbeeck, J.; Bals, S.; Colson, P.; Cloots, R.; Van Tendeloo, G.; Su, B.-L. |
Title |
Well shaped Mn3O4 nano-octahedra with anomalous magnetic behavior and enhanced photodecomposition properties |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Small |
Abbreviated Journal |
Small |
Volume |
7 |
Issue |
4 |
Pages |
475-483 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Very uniform and well shaped Mn3O4 nano-octahedra are synthesized using a simple hydrothermal method under the help of polyethylene glycol (PEG200) as a reductant and shape-directing agent. The nano-octahedra formation mechanism is monitored. The shape and crystal orientation of the nanoparticles is reconstructed by scanning electron microscopy and electron tomography, which reveals that the nano-octahedra only selectively expose {101} facets at the external surfaces. The magnetic testing demonstrates that the Mn3O4 nano-octahedra exhibit anomalous magnetic properties: the Mn3O4 nano-octahedra around 150 nm show a similar Curie temperature and blocking temperature to Mn3O4 nanoparticles with 10 nm size because of the vertical axis of [001] plane and the exposed {101} facets. With these Mn3O4 nano-octahedra as a catalyst, the photodecomposition of rhodamine B is evaluated and it is found that the photodecomposition activity of Mn3O4 nano-octahedra is much superior to that of commercial Mn3O4 powders. The anomalous magnetic properties and high superior photodecomposition activity of well shaped Mn3O4 nano-octahedra should be related to the special shape of the nanoparticles and the abundantly exposed {101} facets at the external surfaces. Therefore, the shape preference can largely broaden the application of the Mn3O4 nano-octahedra. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Weinheim |
Editor |
|
Language |
|
Wos |
000288080400008 |
Publication Date |
2011-01-21 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1613-6810; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
8.643 |
Times cited |
131 |
Open Access |
|
Notes |
This work was realized in the frame of an Interuniversity Attraction Poles Program (Inanomat-P6/17)-Belgian State-Belgian Science Policy and the project “Redugaz”, financially supported by the European community and the Wallon government in the frame of Interreg IV (France-Wallonie). B. L. S. acknowledges the Chinese Central Government for an “Expert of the State” position in the program of “Thousand talents” and the Chinese Ministry of Education for a Changjiang Scholar position at the Wuhan University of Technology. H. T. acknowledges the financial support from FWO-Vlaanderen (Project nr. G.0147.06). J.V. thanks the financial support from the European Union under Framework 6 program for Integrated Infrastructure Initiative, Reference 026019 ESTEEM. |
Approved |
Most recent IF: 8.643; 2011 IF: 8.349 |
Call Number |
UA @ lucian @ c:irua:87908 |
Serial |
3914 |
Permanent link to this record |
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Author |
Monico, L.; van der Snickt, G.; Janssens, K.; de Nolf, W.; Miliani, C.; Verbeeck, J.; Tian, H.; Tan, H.; Dik, J.; Radepont, M.; Cotte, M. |
Title |
Degradation process of lead chromate in paintings by Vincent van Gogh studied by means of synchrotron X-ray spectromicroscopy and related methods : 1 : artificially aged model samples |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
Volume |
83 |
Issue |
4 |
Pages |
1214-1223 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
On several paintings by artists of the end of the 19th century and the beginning of the 20th Century a darkening of the original yellow areas, painted with the chrome yellow pigment (PbCrO4, PbCrO4·xPbSO4, or PbCrO4·xPbO) is observed. The most famous of these are the various Sunflowers paintings Vincent van Gogh made during his career. In the first part of this work, we attempt to elucidate the degradation process of chrome yellow by studying artificially aged model samples. In view of the very thin (1−3 μm) alteration layers that are formed, high lateral resolution spectroscopic methods such as microscopic X-ray absorption near edge (μ-XANES), X-ray fluorescence spectrometry (μ-XRF), and electron energy loss spectrometry (EELS) were employed. Some of these use synchrotron radiation (SR). Additionally, microscopic SR X-ray diffraction (SR μ-XRD), μ-Raman, and mid-FTIR spectroscopy were employed to completely characterize the samples. The formation of Cr(III) compounds at the surface of the chrome yellow paint layers is particularly observed in one aged model sample taken from a historic paint tube (ca. 1914). About two-thirds of the chromium that is present at the surface has reduced from the hexavalent to the trivalent state. The EELS and μ-XANES spectra are consistent with the presence of Cr2O3·2H2O (viridian). Moreover, as demonstrated by μ-XANES, the presence of another Cr(III) compound, such as either Cr2(SO4)3·H2O or (CH3CO2)7Cr3(OH)2 [chromium(III) acetate hydroxide], is likely. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Washington, D.C. |
Editor |
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Language |
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Wos |
000287176900011 |
Publication Date |
2011-02-14 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0003-2700;1520-6882; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.32 |
Times cited |
113 |
Open Access |
|
Notes |
Iuap; Fwo |
Approved |
Most recent IF: 6.32; 2011 IF: 5.856 |
Call Number |
UA @ lucian @ c:irua:88794UA @ admin @ c:irua:88794 |
Serial |
632 |
Permanent link to this record |
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Author |
Paul, M.; Kufer, D.; Müller, A.; Brück, S.; Goering, E.; Kamp, M.; Verbeeck, J.; Tian, H.; Van Tendeloo, G.; Ingle, N.J.C.; Sing, M.; Claessen, R. |
Title |
Fe3O4/ZnO : a high-quality magnetic oxide-semiconductor heterostructure by reactive deposition |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
Volume |
98 |
Issue |
1 |
Pages |
012512,1-012512,3 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
We demonstrate the epitaxial growth of Fe<sub>3</sub>O<sub>4</sub> films on ZnO by a simple reactive deposition procedure using molecular oxygen as an oxidizing agent. X-ray photoelectron spectroscopy results evidence that the iron-oxide surface is nearly stoichiometric magnetite. X-ray diffraction results indicate monocrystalline epitaxy and almost complete structural relaxation. Scanning transmission electron micrographs reveal that the microstructure consists of domains which are separated by antiphase boundaries or twin boundaries. The magnetite films show rather slow magnetization behavior in comparison with bulk crystals probably due to reduced magnetization at antiphase boundaries in small applied fields. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
Language |
|
Wos |
000286009800055 |
Publication Date |
2011-01-07 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0003-6951; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.411 |
Times cited |
27 |
Open Access |
|
Notes |
The authors acknowledge financial support by DFG through Forschergruppe FOR 1162. |
Approved |
Most recent IF: 3.411; 2011 IF: 3.844 |
Call Number |
UA @ lucian @ c:irua:88653 |
Serial |
3532 |
Permanent link to this record |
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Author |
Rubino, S.; Schattschneider, P.; Rusz, J.; Verbeeck, J.; Leifer, K. |
Title |
Simulation of magnetic circular dichroism in the electron microscope |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Journal of physics: D: applied physics |
Abbreviated Journal |
J Phys D Appl Phys |
Volume |
43 |
Issue |
47 |
Pages |
474005,1-474005,11 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
As electron energy-loss spectroscopy (EELS) and x-ray absorption spectroscopy (XAS) probe the same transitions from coreshell states to unoccupied states above the Fermi energy, it should always be possible to apply the two techniques to the same physical phenomena, such as magnetic dichroism, and obtain the same information. Indeed, the similarity in the expression of the electron and x-ray cross-sections had been already exploited to prove the equivalence of x-ray magnetic linear dichroism and anisotropy in EELS, by noting that the polarization vector of a photon plays the same role as the momentum transfer in electron scattering. Recently, the same was proven true for x-ray magnetic circular dichroism (XMCD) by establishing a new TEM technique called EMCD (electron energy-loss magnetic chiral dichroism) (Schattschneider P et al 2006 Nature 441 4868), which makes use of special electron scattering conditions to force the absorption of a circularly polarized virtual photon. The intrinsic advantage of EMCD over XMCD is the high spatial resolution of electron microscopes, which are readily available. Among the particular obstacles in EMCD that do not exist for synchrotron radiation, is the notoriously low signal and the very particular scattering conditions necessary to observe a chiral dichroic signal. In spite of that, impressive progress has been made in recent years. The signal strength could be considerably increased, and some innovations such as using a convergent beam have been introduced. EMCD has evolved into several techniques, which make full use of the versatility of the TEM and energy filtering, spectroscopy or STEM conditions (Rubino S 2007 Magnetic circular dichroism in the transmission electron microscope PhD Thesis Vienna University of Technology, Vienna, Austria). |
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 |
|
Language |
|
Wos |
000284099700006 |
Publication Date |
2010-11-12 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0022-3727;1361-6463; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.588 |
Times cited |
13 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.588; 2010 IF: 2.109 |
Call Number |
UA @ lucian @ c:irua:85808UA @ admin @ c:irua:85808 |
Serial |
3012 |
Permanent link to this record |
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|
|
Author |
Schattschneider, P.; Verbeeck, J.; Mauchamp, V.; Jaouen, M.; Hamon, A.-L. |
Title |
Real-space simulations of spin-polarized electronic transitions in iron |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
82 |
Issue |
14 |
Pages |
144418-144418,11 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
After the advent of energy-loss magnetic chiral dichroism (EMCD) in 2006, rapid progress in theoretical understanding and in experimental performance was achieved, recently demonstrating a spatial resolution of better than 2 nm. Similar to the x-ray magnetic circular dichroism technique, EMCD is used to study atom specific magnetic moments. The latest generation of electron microscopes opens the road to the mapping of spin moments on the atomic scale with this method. Here the theoretical background to reach this challenging aim is elaborated. Numerical simulations of the L3 transition in an Fe specimen, based on a combination of the density-matrix approach for inelastic electron scattering with the propagation of the probe electron in the lattice potential indicate the feasibility of single spin mapping in the electron microscope. |
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 |
000282678900006 |
Publication Date |
2010-10-08 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
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Series Volume |
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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 |
11 |
Open Access |
|
Notes |
P.S. acknowledges the support of the Austrian Science Fund, Project No. I543-N20. |
Approved |
Most recent IF: 3.836; 2010 IF: 3.774 |
Call Number |
UA @ lucian @ c:irua:85029UA @ admin @ c:irua:85029 |
Serial |
2832 |
Permanent link to this record |
|
|
|
Author |
Burriel, M.; Casa-Cabanas, M.; Zapata, J.; Tan, H.; Verbeeck, J.; Solis, C.; Roqueta, J.; Skinner, S.J.; Kilner, J.A.; Van Tendeloo, G.; Santiso, J. |
Title |
Influence of the microstructure on the high-temperature transport properties of GdBaCo2O5.5+\delta epitaxial films |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
Volume |
22 |
Issue |
19 |
Pages |
5512-5520 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Epitaxial thin films of GdBaCo2O5.5+δ (GBCO) grown by pulsed laser deposition have been studied as a function of deposition conditions. The variation in film structure, domain orientation, and microstructure upon deviations in the cation composition have been correlated with the charge transport properties of the films. The epitaxial GBCO films mainly consist of single- and double-perovskite regions that are oriented in different directions depending on the deposition temperature. Additionally, cobalt depletion induces the formation of a high density of stacking defects in the films, consisting of supplementary GdO planes along the c-axis of the material. The presence of such defects progressively reduces the electrical conductivity. The films closer to the stoichiometric composition have shown p-type electronic conductivity at high pO2 with values as high as 800 S/cm at 330 °C in 1 atm O2, and with a pO2 power dependence with an exponent as low as 1/25, consistent with the behavior reported for bulk GBCO. These values place GBCO thin films as a very promising material to be applied as cathodes in intermediate temperature solid oxide fuel cells. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
Language |
|
Wos |
000282471000013 |
Publication Date |
2010-09-20 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0897-4756;1520-5002; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
9.466 |
Times cited |
17 |
Open Access |
|
Notes |
Fwo; Esteem 026019 |
Approved |
Most recent IF: 9.466; 2010 IF: 6.400 |
Call Number |
UA @ lucian @ c:irua:85412UA @ admin @ c:irua:85412 |
Serial |
1648 |
Permanent link to this record |
|
|
|
Author |
Hadermann, J.; Abakumov, A.M.; Perkisas, T.; d' Hondt, H.; Tan, H.; Verbeeck, J.; Filonenko, V.P.; Antipov, E.V.; Van Tendeloo, G. |
Title |
New perovskite-based manganite Pb2Mn2O5 |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Journal of solid state chemistry |
Abbreviated Journal |
J Solid State Chem |
Volume |
183 |
Issue |
183 |
Pages |
2190-2195 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
A new perovskite based compound Pb2Mn2O5 has been synthesized using a high pressure high temperature technique. The structure model of Pb2Mn2O5 is proposed based on electron diffraction, high angle annular dark field scanning transmission electron microscopy and high resolution transmission electron microscopy. The compound crystallizes in an orthorhombic unit cell with parameters a=5.736(1)Å≈√2a p p p (a p the parameter of the perovskite subcell) and space group Pnma. The Pb2Mn2O5 structure consists of quasi two-dimensional perovskite blocks separated by 1/2[110] p (1̄01) p crystallographic shear planes. The blocks are connected to each other by chains of edge-sharing MnO5 distorted tetragonal pyramids. The chains of MnO5 pyramids and the MnO6 octahedra of the perovskite blocks delimit six-sided tunnels accommodating double chains of Pb atoms. The tunnels and pyramidal chains adopt two mirror-related configurations (left L and right R) and layers consisting of chains and tunnels of the same configuration alternate in the structure according to an -LRLR-sequence. The sequence is sometimes locally violated by the appearance of -LL- or -RR-fragments. A scheme is proposed with a JahnTeller distortion of the MnO6 octahedra with two long and two short bonds lying in the ac plane, along two perpendicular orientations within this plane, forming a d-type pattern. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
London |
Editor |
|
Language |
|
Wos |
000282139600041 |
Publication Date |
2010-07-25 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0022-4596; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.299 |
Times cited |
8 |
Open Access |
|
Notes |
Fwo; Bof; Esteem 026019 |
Approved |
Most recent IF: 2.299; 2010 IF: 2.261 |
Call Number |
UA @ lucian @ c:irua:85472UA @ admin @ c:irua:85472 |
Serial |
2332 |
Permanent link to this record |
|
|
|
Author |
Verbeeck, J.; Tian, H.; Schattschneider, P. |
Title |
Production and application of electron vortex beams |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Nature |
Abbreviated Journal |
Nature |
Volume |
467 |
Issue |
7313 |
Pages |
301-304 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Vortex beams (also known as beams with a phase singularity) consist of spiralling wavefronts that give rise to angular momentum around the propagation direction. Vortex photon beams are widely used in applications such as optical tweezers to manipulate micrometre-sized particles and in micro-motors to provide angular momentum1, 2, improving channel capacity in optical3 and radio-wave4 information transfer, astrophysics5 and so on6. Very recently, an experimental realization of vortex beams formed of electrons was demonstrated7. Here we describe the creation of vortex electron beams, making use of a versatile holographic reconstruction technique in a transmission electron microscope. This technique is a reproducible method of creating vortex electron beams in a conventional electron microscope. We demonstrate how they may be used in electron energy-loss spectroscopy to detect the magnetic state of materials and describe their properties. Our results show that electron vortex beams hold promise for new applications, in particular for analysing and manipulating nanomaterials, and can be easily produced. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
London |
Editor |
|
Language |
|
Wos |
000281824900033 |
Publication Date |
2010-09-14 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0028-0836;1476-4687; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
40.137 |
Times cited |
626 |
Open Access |
|
Notes |
Esteem 026019; Fwo |
Approved |
Most recent IF: 40.137; 2010 IF: 36.104 |
Call Number |
UA @ lucian @ c:irua:84878UA @ admin @ c:irua:84878 |
Serial |
2720 |
Permanent link to this record |
|
|
|
Author |
Gehrke, K.; Moshnyaga, V.; Samwer, K.; Lebedev, O.I.; Verbeeck, J.; Kirilenko, D.; Van Tendeloo, G. |
Title |
Interface controlled electronic variations in correlated heterostructures |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
82 |
Issue |
11 |
Pages |
113101,1-113101,4 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
An interface modification of (LaCa)MnO3-BaTiO3 superlattices was found to massively influence magnetic and magnetotransport properties. Moreover it determines the crystal structure of the manganite layers, changing it from orthorhombic (Pnma) for the conventional superlattice (cSL), to rhombohedral (R3̅ c) for the modified one (mSL). While the cSL shows extremely nonlinear ac transport, the mSL is an electrically homogeneous material. The observations go beyond an oversimplified picture of dead interface layers and evidence the importance of electronic correlations at perovskite interfaces. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000281643200001 |
Publication Date |
2010-09-07 |
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 |
9 |
Open Access |
|
Notes |
This work was supported by DFG via SFB 602, TPA2. |
Approved |
Most recent IF: 3.836; 2010 IF: 3.774 |
Call Number |
UA @ lucian @ c:irua:84249UA @ admin @ c:irua:84249 |
Serial |
1691 |
Permanent link to this record |
|
|
|
Author |
Schattschneider, P.; Ennen, I.; Stoger-Pollach, M.; Verbeeck, J.; Mauchamp, V.; Jaouen, M. |
Title |
Real space maps of magnetic moments on the atomic scale: theory and feasibility |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
110 |
Issue |
8 |
Pages |
1038-1041 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The recently discovered EMCD technique (energy loss magnetic chiral dichroism) can detect atom specific magnetic moments with nanometer resolution, exploiting the spin selectivity of electronic transitions in energy loss spectroscopy. Yet, direct imaging of magnetic moments on the atomic scale is not possible. In this paper we present an extension of EMCD that can overcome this limit. As a model system we chose bcc Fe. We present image simulations of the L3 white line signal, based on the kinetic equation for the density matrix of the 200 kV probe electron. With actual progress in instrumentation (high brightness sources, aberration corrected lenses) this technique should allow direct imaging of spin moments on the atomic scale. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000281216600016 |
Publication Date |
2009-12-07 |
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 |
10 |
Open Access |
|
Notes |
--- |
Approved |
Most recent IF: 2.843; 2010 IF: 2.063 |
Call Number |
UA @ lucian @ c:irua:84439UA @ admin @ c:irua:84439 |
Serial |
2830 |
Permanent link to this record |
|
|
|
Author |
Hadermann, J.; Abakumov, A.M.; Tsirlin, A.A.; Filonenko, V.P.; Gonnissen, J.; Tan, H.; Verbeeck, J.; Gemmi, M.; Antipov, E.V.; Rosner, H. |
Title |
Direct space structure solution from precession electron diffraction data: resolving heavy and light scatterers in Pb13Mn9O25 |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
110 |
Issue |
7 |
Pages |
881-890 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The crystal structure of a novel compound Pb13Mn9O25 has been determined through a direct space structure solution with a Monte-Carlo-based global optimization using precession electron diffraction data (a=14.177(3) Å, c=3.9320(7) Å, SG P4/m, RF=0.239) and compositional information obtained from energy dispersive X-ray analysis and electron energy loss spectroscopy. This allowed to obtain a reliable structural model even despite the simultaneous presence of both heavy (Pb) and light (O) scattering elements and to validate the accuracy of the electron diffraction-based structure refinement. This provides an important benchmark for further studies of complex structural problems with electron diffraction techniques. Pb13Mn9O25 has an anion- and cation-deficient perovskite-based structure with the A-positions filled by the Pb atoms and 9/13 of the B positions filled by the Mn atoms in an ordered manner. MnO6 octahedra and MnO5 tetragonal pyramids form a network by sharing common corners. Tunnels are formed in the network due to an ordered arrangement of vacancies at the B-sublattice. These tunnels provide sufficient space for localization of the lone 6s2 electron pairs of the Pb2+ cations, suggested as the driving force for the structural difference between Pb13Mn9O25 and the manganites of alkali-earth elements with similar compositions. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000280050900023 |
Publication Date |
2010-04-01 |
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 |
24 |
Open Access |
|
Notes |
Fwo; Bof; Esteem |
Approved |
Most recent IF: 2.843; 2010 IF: 2.063 |
Call Number |
UA @ lucian @ c:irua:84085UA @ admin @ c:irua:84085 |
Serial |
721 |
Permanent link to this record |
|
|
|
Author |
Li, Y.; Tan, H.; Lebedev, O.; Verbeeck, J.; Biermans, E.; Van Tendeloo, G.; Su, B.-L. |
Title |
Insight into the growth of multiple branched MnOOH nanorods |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Crystal growth & design |
Abbreviated Journal |
Cryst Growth Des |
Volume |
10 |
Issue |
7 |
Pages |
2969-2976 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Multiple branched manganese oxide hydroxide (MnOOH) nanorods prepared by a hydrothermal process were extensively studied by transmission electron microscopy (TEM). A model of the branch formation is proposed together with a study of the interface structure. The sword-like tip plays a crucial role for the nanorods to form different shapes. Importantly, the branching occurs at an angle of around either 57 degrees or 123 degrees. Specifically, a (111) twin plane can only be formed at the interface with a 123 degrees angle. The interfaces formed with a 57 degrees angle usually contain edge dislocations. Electron energy loss spectroscopy (EELS) demonstrates that the whole crystal has a uniform chemical composition. Interestingly, an epitaxial growth of Mn3O4 at the radial surface was also observed under electron beam irradiation; this is because of the rough purification of the products. The proposed mechanism is expected to shed light on the branched/dendrite nanostructure growth and to provide opportunities for further novel nanomaterial structure growth and design. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000279422700027 |
Publication Date |
2010-06-08 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1528-7483;1528-7505; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.055 |
Times cited |
41 |
Open Access |
|
Notes |
Fwo; Esteem 026019 |
Approved |
Most recent IF: 4.055; 2010 IF: 4.390 |
Call Number |
UA @ lucian @ c:irua:83886UA @ admin @ c:irua:83886 |
Serial |
1672 |
Permanent link to this record |
|
|
|
Author |
Schattschneider, P.; Ennen, I.; Stoger-Pollach, M.; Verbeeck, J. |
Title |
Circular dichroism in the electron microscope: progress and applications (invited) |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Journal of applied physics |
Abbreviated Journal |
J Appl Phys |
Volume |
107 |
Issue |
9 |
Pages |
09d311,1-09d311,6 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
According to theory, x-ray magnetic circular dichroism in a synchrotron is equivalent to energy loss magnetic chiral dichroism (EMCD) in a transmission electron microscope (TEM). After a synopsis of the development of EMCD, the theoretical background is reviewed and recent results are presented, focusing on the study of magnetic nanoparticles for ferrofluids and Heusler alloys for spintronic devices. Simulated maps of the dichroic strength as a function of atom position in the crystal allow evaluating the influence of specimen thickness and sample tilt on the experimental EMCD signal. Finally, the possibility of direct observation of chiral electronic transitions with atomic resolution in a TEM is discussed. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
Language |
|
Wos |
000277834300276 |
Publication Date |
2010-05-12 |
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 |
28 |
Open Access |
|
Notes |
Esteem |
Approved |
Most recent IF: 2.068; 2010 IF: 2.079 |
Call Number |
UA @ lucian @ c:irua:83653UA @ admin @ c:irua:83653 |
Serial |
361 |
Permanent link to this record |
|
|
|
Author |
Jorissen, K.; Rehr, J.J.; Verbeeck, J. |
Title |
Multiple scattering calculations of relativistic electron energy loss spectra |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
81 |
Issue |
15 |
Pages |
155108,1-155108,6 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
A generalization of the real-space Greens-function approach is presented for ab initio calculations of relativistic electron energy loss spectra (EELS) which are particularly important in anisotropic materials. The approach incorporates relativistic effects in terms of the transition tensor within the dipole-selection rule. In particular, the method accounts for relativistic corrections to the magic angle in orientation resolved EELS experiments. The approach is validated by a study of the graphite C K edge, for which we present an accurate magic angle measurement consistent with the predicted value. |
Address |
|
Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000277210500038 |
Publication Date |
2010-04-13 |
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 |
24 |
Open Access |
|
Notes |
Fwo; Esteem 026019 |
Approved |
Most recent IF: 3.836; 2010 IF: 3.774 |
Call Number |
UA @ lucian @ c:irua:82805UA @ admin @ c:irua:82805 |
Serial |
2230 |
Permanent link to this record |
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|
|
Author |
Afanasov, I.M.; Shornikova, O.N.; Kirilenko, D.A.; Vlasov, I.I.; Zhang, L.; Verbeeck, J.; Avdeev, V.V.; Van Tendeloo, G. |
Title |
Graphite structural transformations during intercalation by HNO3 and exfoliation |
Type |
L1 Letter to the editor |
Year |
2010 |
Publication |
Carbon |
Abbreviated Journal |
Carbon |
Volume |
48 |
Issue |
6 |
Pages |
1862-1865 |
Keywords |
L1 Letter to the editor; Electron microscopy for materials research (EMAT) |
Abstract |
Expandable graphite of two types was synthesized by (1) hydrolysis of graphite nitrate of II stage and (2) anodic polarization of graphite in 60% HNO3. Exfoliated graphite samples were produced by thermal shock of expandable graphite samples in air at 900 °C. A comparative study of microstructural distinctions of both expandable and exfoliated graphite samples was carried out using X-ray diffraction, Raman spectroscopy, electron energy loss spectroscopy and high resolution transmission electron microscopy. |
Address |
|
Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
Oxford |
Editor |
|
Language |
|
Wos |
000276132800021 |
Publication Date |
2010-02-02 |
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 |
43 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 6.337; 2010 IF: 4.896 |
Call Number |
UA @ lucian @ c:irua:82315UA @ admin @ c:irua:82315 |
Serial |
1379 |
Permanent link to this record |
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|
|
Author |
Verbeeck, J.; Bals, S.; Lamoen, D.; Luysberg, M.; Huijben, M.; Rijnders, G.; Brinkman, A.; Hilgenkamp, H.; Blank, D.H.A.; Van Tendeloo, G. |
Title |
Electronic reconstruction at n-type SrTiO3/LaAlO3 interfaces |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
81 |
Issue |
8 |
Pages |
085113,1-085113,6 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Electron-energy-loss spectroscopy (EELS) is used to investigate single layers of LaAlO3 grown on SrTiO3 having an n-type interface as well as multilayers of LaAlO3 and SrTiO3 in which both n- and p-type interfaces occur. Only minor changes in Ti valence at the n-type interface are observed. This finding seems to contradict earlier experiments for other SrTiO3/LaAlO3 systems where large deviations in Ti valency were assumed to be responsible for the conductivity of these interfaces. Ab initio calculations have been carried out in order to interpret our EELS results. Using the concept of Bader charges, it is demonstrated that the so-called polar discontinuity is mainly resolved by lattice distortions and to a far lesser extent by changes in valency for both single layer and multilayer geometries. |
Address |
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Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000275053300040 |
Publication Date |
2010-02-18 |
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 |
25 |
Open Access |
|
Notes |
Esteem 026019; Fwo |
Approved |
Most recent IF: 3.836; 2010 IF: 3.774 |
Call Number |
UA @ lucian @ c:irua:81768UA @ admin @ c:irua:81768 |
Serial |
1005 |
Permanent link to this record |
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|
|
Author |
Zhang, L.; Turner, S.; Brosens, F.; Verbeeck, J. |
Title |
Model-based determination of dielectric function by STEM low-loss EELS |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
81 |
Issue |
3 |
Pages |
035102 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Theory of quantum systems and complex systems |
Abstract |
Dielectric properties of materials are crucial in describing the electromagnetic response of materials. As devices are becoming considerably smaller than the optical wavelength, the conventional measuring methods based on optical response are limited by their spatial resolution. Electron energy loss spectroscopy performed in a scanning transmission electron microscope is a good alternative to obtain the dielectric properties with excellent spatial resolution. Due to the overlap of diffraction discs in scanning transmission electron microscopy, it is difficult to apply conventional experimental settings to suppress retardation losses. In this contribution, a relativistic dielectric model for the loss function is presented which is used in a model based optimization scheme to estimate the complex dielectric function of a material. The method is applied to experiments on bulk diamond and SrTiO3 and shows a good agreement with optical reference data when retardation effects are included. Application of this technique to nanoparticles is possible but several theoretical assumptions made in the model of the loss function are violated and interpretation becomes problematic. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
Language |
|
Wos |
000274002300027 |
Publication Date |
2010-01-08 |
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 |
9 |
Open Access |
|
Notes |
Esteem – 026019; Fwo |
Approved |
Most recent IF: 3.836; 2010 IF: 3.774 |
Call Number |
UA @ lucian @ c:irua:81258UA @ admin @ c:irua:81258 |
Serial |
2098 |
Permanent link to this record |
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Author |
Bach, D.; Schneider, R.; Gerthsen, D.; Verbeeck, J.; Sigle, W. |
Title |
EELS of niobium and stoichiometric niobium-oxide phases: part 1: plasmon and Near-edges fine structure |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Microscopy and microanalysis |
Abbreviated Journal |
Microsc Microanal |
Volume |
15 |
Issue |
6 |
Pages |
505-523 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
A comprehensive electron energy-loss spectroscopy study of niobium (Nb) and stable Nb-oxide phases (NbO, NbO2, Nb2O5) was carried out. In this work (Part I), the plasmons and energy-loss near-edge structures (ELNES) of all relevant Nb edges (Nb-N2,3, Nb-M4,5, Nb-M2,3, Nb-M1, and Nb-L2,3) up to energy losses of about 2600 eV and the O-K edge are analyzed with respect to achieving characteristic fingerprints of Nb in different formal oxidation states (0 for metallic Nb, +2 for NbO, +4 for NbO2, and +5 for Nb2O5). Chemical shifts of the Nb-N2,3, Nb-M4,5, Nb-M2,3, and Nb-L2,3 edges are extracted from the spectra that amount to about 4 eV as the oxidation state increases from 0 for Nb to +5 for Nb2O5. Four different microscopes, including a 200 keV ZEISS Libra with monochromator, were used. The corresponding wide range of experimental parameters with respect to the primary electron energy, convergence, and collection semi-angles as well as energy resolution allows an assessment of the influence of the experimental setup on the ELNES of the different edges. Finally, the intensity of the Nb-L2,3 white-line edges is correlated with niobium 4d-state occupancy in the different reference materials. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Cambridge, Mass. |
Editor |
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Language |
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Wos |
000272433200005 |
Publication Date |
2009-10-27 |
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 |
1431-9276;1435-8115; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.891 |
Times cited |
55 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 1.891; 2009 IF: 3.035 |
Call Number |
UA @ lucian @ c:irua:80320UA @ admin @ c:irua:80320 |
Serial |
790 |
Permanent link to this record |
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Author |
Verbeeck, J.; Bertoni, G. |
Title |
Deconvolution of core electron energy loss spectra |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
109 |
Issue |
11 |
Pages |
1343-1352 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Different deconvolution methods for removing multiple scattering and instrumental broadening from core loss electron energy loss spectra are compared with special attention to the artefacts they introduce. The Gaussian modifier method, Wiener filter, maximum entropy, and model based methods are described. Their performance is compared on virtual spectra where the true single scattering distribution is known. A test on experimental spectra confirms the good performance of model based deconvolution in comparison to maximum entropy methods and shows the advantage of knowing the estimated error bars from a single spectrum acquisition. |
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 |
000270765800005 |
Publication Date |
2009-07-01 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
|
Edition |
|
ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.843 |
Times cited |
13 |
Open Access |
|
Notes |
Fwo; Esteem 026019 |
Approved |
Most recent IF: 2.843; 2009 IF: 2.067 |
Call Number |
UA @ lucian @ c:irua:79073UA @ admin @ c:irua:79073 |
Serial |
610 |
Permanent link to this record |
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Author |
Van Aert, S.; Verbeeck, J.; Erni, R.; Bals, S.; Luysberg, M.; van Dyck, D.; Van Tendeloo, G. |
Title |
Quantitative atomic resolution mapping using high-angle annular dark field scanning transmission electron microscopy |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
109 |
Issue |
10 |
Pages |
1236-1244 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
Abstract |
A model-based method is proposed to relatively quantify the chemical composition of atomic columns using high angle annular dark field (HAADF) scanning transmission electron microscopy (STEM) images. The method is based on a quantification of the total intensity of the scattered electrons for the individual atomic columns using statistical parameter estimation theory. In order to apply this theory, a model is required describing the image contrast of the HAADF STEM images. Therefore, a simple, effective incoherent model has been assumed which takes the probe intensity profile into account. The scattered intensities can then be estimated by fitting this model to an experimental HAADF STEM image. These estimates are used as a performance measure to distinguish between different atomic column types and to identify the nature of unknown columns with good accuracy and precision using statistical hypothesis testing. The reliability of the method is supported by means of simulated HAADF STEM images as well as a combination of experimental images and electron energy-loss spectra. It is experimentally shown that statistically meaningful information on the composition of individual columns can be obtained even if the difference in averaged atomic number Z is only 3. Using this method, quantitative mapping at atomic resolution using HAADF STEM images only has become possible without the need of simultaneously recorded electron energy loss spectra. |
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 |
000270015200004 |
Publication Date |
2009-05-28 |
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 |
|
ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.843 |
Times cited |
166 |
Open Access |
|
Notes |
Fwo; Esteem 026019 |
Approved |
Most recent IF: 2.843; 2009 IF: 2.067 |
Call Number |
UA @ lucian @ c:irua:78585UA @ admin @ c:irua:78585 |
Serial |
2748 |
Permanent link to this record |
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Author |
Abakumov, A.M.; Hadermann, J.; Tsirlin, A.A.; Tan, H.; Verbeeck, J.; Zhang, H.; Dikarev, E.V.; Shpanchenko, R.V.; Antipov, E.V. |
Title |
Original close-packed structure and magnetic properties of the Pb4Mn9O20 manganite |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Journal of solid state chemistry |
Abbreviated Journal |
J Solid State Chem |
Volume |
182 |
Issue |
8 |
Pages |
2231-2238 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The crystal structure of the Pb4Mn9O20 compound (previously known as Pb0.43MnO2.18) was solved from powder X-ray diffraction, electron diffraction, and high resolution electron microscopy data (S.G. Pnma, a=13.8888(2) Å, b=11.2665(2) Å, c=9.9867(1) Å, RI=0.016, RP=0.047). The structure is based on a 6H (cch)2 close packing of pure oxygen h-type (O16) layers alternating with mixed c-type (Pb4O12) layers. The Mn atoms occupy octahedral interstices formed by the oxygen atoms of the close-packed layers. The MnO6 octahedra share edges within the layers, whereas the octahedra in neighboring layers are linked through corner sharing. The relationship with the closely related Pb3Mn7O15 structure is discussed. Magnetization measurements reveal a peculiar magnetic behavior with a phase transition at 52 K, a small net magnetization below the transition temperature, and a tendency towards spin freezing. |
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 |
000269066400035 |
Publication Date |
2009-06-12 |
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 |
0022-4596; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.299 |
Times cited |
5 |
Open Access |
|
Notes |
The authors are grateful to Christoph Geibel for the help in magnetization measurements. A.Ts. acknowledges MPI CKS for hospitality and financial support during the stay. E.D. thanks the National Science Foundation (CHE-0718900) for financial support. This work was supported by the Russian Foundation of Basic Research (RFBR Grants 07-03-00664-a, 06-03-90168-a and 07-03-00890-a). The authors acknowledge financial support from the European Union under the Framework 6 program under a contract for an Integrated Infrastructure Initiative. Reference 026019 ESTEEM. |
Approved |
Most recent IF: 2.299; 2009 IF: 2.340 |
Call Number |
UA @ lucian @ c:irua:78935UA @ admin @ c:irua:78935 |
Serial |
2529 |
Permanent link to this record |
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Author |
Turner, S.; Lebedev, O.I.; Shenderova, O.; Vlasov, I.I.; Verbeeck, J.; Van Tendeloo, G. |
Title |
Determination of size, morphology, and nitrogen impurity location in treated detonation nanodiamond by transmission electron microscopy |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Advanced functional materials |
Abbreviated Journal |
Adv Funct Mater |
Volume |
19 |
Issue |
13 |
Pages |
2116-2124 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Size, morphology, and nitrogen impurity location, all of which are all thought to be related to the luminescent properties of detonation nanodiamonds, are determined in several detonation nanodiamond samples using a combination of transmission electron microscopy techniques. Results obtained from annealed and cleaned detonation nanodiamond samples are compared to results from conventionally purified detonation nanodiamond. Detailed electron energy loss spectroscopy combined with model-based quantification provides direct evidence for the sp3 like embedding of nitrogen impurities into the diamond cores of all the studied nanodiamond samples. Simultaneously, the structure and morphology of the cleaned detonation nanodiamond particles are studied using high resolution transmission electron microscopy. The results show that the size and morphology of detonation nanodiamonds can be modified by temperature treatment and that by applying a special cleaning procedure after temperature treatment, nanodiamond particles with clean facets almost free from sp2 carbon can be prepared. These clean facets are clear evidence that nanodiamond cores are not necessarily in coexistence with a graphitic shell of non-diamond carbon. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Weinheim |
Editor |
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Language |
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Wos |
000268297800012 |
Publication Date |
2009-05-12 |
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 |
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ISSN |
1616-301X;1616-3028; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
12.124 |
Times cited |
100 |
Open Access |
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Notes |
Esteem 026019 |
Approved |
Most recent IF: 12.124; 2009 IF: 6.990 |
Call Number |
UA @ lucian @ c:irua:78261UA @ admin @ c:irua:78261 |
Serial |
674 |
Permanent link to this record |
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Author |
Schattschneider, P.; Verbeeck, J.; Hamon, A.L. |
Title |
Real space maps of atomic transitions |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
109 |
Issue |
7 |
Pages |
781-787 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Considering the rapid technical development of transmission electron microscopes, we investigate the possibility to map electronic transitions in real space on the atomic scale. To this purpose, we analyse the information carried by the scatterer's initial and final state wave functions and the role of the different atomic transition channels for the inelastic scattering cross section. It is shown that the change in the magnetic quantum number in the transition can be mapped. Two experimental set-ups are proposed, one blocking half the diffraction plane, the other one using a cylinder lens for imaging. Both methods break the conventional circular symmetry in the electron microscope making it possible to detect the handedness of electronic transitions as an asymmetry in the image intensity. This finding is of important for atomic resolution energy-loss magnetic chiral dichroism (EMCD), allowing to obtain the magnetic moments of single atoms. |
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 |
000266787900002 |
Publication Date |
2009-03-01 |
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 |
10 |
Open Access |
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Notes |
J.V. acknowledges the FWO-Vlaanderen for support (contract no. G.0147.06) and the European Union under the Framework 6 program under a contract for an Integrated Infrastructure Initiative. Reference 026019 ESTEEM. |
Approved |
Most recent IF: 2.843; 2009 IF: 2.067 |
Call Number |
UA @ lucian @ c:irua:77360UA @ admin @ c:irua:77360 |
Serial |
2829 |
Permanent link to this record |
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Author |
Moshnyaga, V.; Gehrke, K.; Sudheendra, L.; Belenchuk, A.; Raabe, S.; Shapoval, O.; Verbeeck, J.; Van Tendeloo, G.; Samwer, K. |
Title |
Electrical nonlinearity in colossal magnetoresistance manganite films: relevance of correlated polarons |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Physical review : B : solid state |
Abbreviated Journal |
Phys Rev B |
Volume |
79 |
Issue |
13 |
Pages |
134413,1-134413,8 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The metal-insulator (MI) transition in epitaxial thin films of La0.75Ca0.25MnO3 (LCMO) is accompanied by the appearance of an intrinsic electrical nonlinearity. The latter, probed by electrical third harmonic voltage, U3, or resistance, R3=dU3/dJ, is drastically enhanced in the vicinity of the MI transition, TMI=267 K. Applied magnetic field, B=5 T, suppresses the nonlinearity, resulting in a huge nonlinear CMR3(TMI)~105%. R3 shows a peculiar low-frequency (1 kHz) dependence, R3~(-0)n, with exponent, n, changing across the MI transition from n~1,52 for TTMI to n=1 (T<TMI). The observed electrical nonlinearity in LCMO reflects the behavior of correlated polarons, the number of which dramatically enhances in the vicinity of TMI. We argued that correlated polarons, considered as electric-elastic quadrupoles, provide a nonlinear (quadratic) coupling to the electric field, yielding a third harmonic electric nonlinearity in LCMO. The reference film of La0.7Sr0.3MnO3 (LSMO), a prototypic double exchange system with second-order phase transition, is characterized as a linear metallic material in the whole range of temperatures (T=10400 K), magnetic fields (B=05 T), and frequencies (=11000 Hz). |
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 |
000265942800074 |
Publication Date |
2009-04-09 |
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 |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
28 |
Open Access |
|
Notes |
Esteem 026019 |
Approved |
Most recent IF: 3.836; 2009 IF: 3.475 |
Call Number |
UA @ lucian @ c:irua:77022UA @ admin @ c:irua:77022 |
Serial |
893 |
Permanent link to this record |