| Records |
| Author |
de Nolf, W.; Dik, J.; van der Snickt, G.; Wallert, A.; Janssens, K. |
| Title |
High energy X-ray powder diffraction for the imaging of (hidden) paintings |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Journal of analytical atomic spectrometry |
Abbreviated Journal |
J Anal Atom Spectrom |
| Volume |
26 |
Issue |
5 |
Pages |
910-916 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
Over the past few years a number of innovative imaging techniques have been introduced for the visualization of hidden paint layers in Old Master Paintings. These include X-ray fluorescence scanning, TeraHertz imaging, optical coherence tomography and other acoustics-based forms of visualization. All of these techniques are usually a trade-off between their penetrative capability on the one side and their analytical precision in terms of spatial resolution and material identification on the other. Here, we present the first-time use of High-Energy X-ray Powder Diffraction imaging (HE-XRPD) in the study of hidden layers in paintings. As an imaging tool, it combines high-depth sensitivity with fingerprint identification of most inorganic painting materials. The potential as well as some limitations of this technique are demonstrated using model paintings as well as an authentic 16th century painting. |
| 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 |
|
| Language |
|
Wos |
000289731900005 |
Publication Date |
2011-03-17 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0267-9477 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor  |
3.379 |
Times cited |
34 |
Open Access |
|
| Notes |
; ; |
Approved |
Most recent IF: 3.379; 2011 IF: 3.220 |
| Call Number |
UA @ admin @ c:irua:89922 |
Serial |
5640 |
| Permanent link to this record |
| |
|
| |
| Author |
van der Snickt, G.; Miliani, C.; Janssens, K.; Brunetti, B.G.; Romani, A.; Rosi, F.; Walter, P.; Castaing, J.; de Nolf, W.; Klaassen, L.; Labarque, I.; Wittermann, R. |
| Title |
Material analyses of “Christ with singing and music-making Angels”, a late 15th-C panel painting attributed to Hans Memling and assistants : part 1 : non-invasive in situ investigations |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Journal of analytical atomic spectrometry |
Abbreviated Journal |
J Anal Atom Spectrom |
| Volume |
26 |
Issue |
11 |
Pages |
2216-2229 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
In cultural heritage science, compositional data is traditionally obtained from works of art through the analysis of samples by means of various bench-top instruments (scanning electron microscope, Raman spectrometer, etc.). Alternatively, the object can be transported to a laboratory where it may be examined, usually by spectroscopic methods working in reflection mode. However, this paper describes how a complementary set of mobile and portable instruments was deployed in situ to gain a comprehensive view on the materials and related ageing compounds of an (almost) unmovable 15th-C polyptych, prior to and in preparation of the extraction of a limited number of samples. In line with the methodological approach discussed, PXRF was first employed as an efficient screening tool. The ensuing elemental data was supplemented by more specific information on both organic as inorganic materials supplied by reflection near- and mid-FTIR spectroscopy and fluorimetry. In completion, a limited number of diffraction patterns were collected with a mobile XRD instrument in order to identify the constituent crystalline phases in pigments, grounding materials and degradation products. In this way, it could be demonstrated how a rich array of colours was obtained by means of a limited palette of pigments: lead white, lead tin yellow, azurite, natural ultramarine, bone black, vermillion, madder lake, and a green copper-organo complex were detected and situated on the panels. Remarkably, next to chalk also gypsum was found in the ground layer(s) of this Western European easel painting. The relatively large surface of the background was covered with gold leaf; the analyses seem to point towards the labour-intensive water gilding technique. The versatility of this combination of analytical techniques was further illustrated by the accurate characterisation of degradation products affecting the readability and conservation of the painting: the overall presence of a calcium oxalate-based film of variable thickness was established. Nevertheless, further analysis of cross-sectioned samples was considered desirable in order to study the stratigraphy, to gain direct access to altered and sub-imposed layers and to allow highly detailed analysis of micrometric degradation products by state-of-the art techniques (i.e. synchrotron radiation). |
| 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 |
|
| Language |
|
Wos |
000296021800010 |
Publication Date |
2011-09-23 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0267-9477 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.379 |
Times cited |
32 |
Open Access |
|
| Notes |
; This research was supported by the Interuniversity Attraction Poles Programme – Belgian Science Policy (IUAP VI/16). The text also presents results of GOA “XANES meets ELNES” (Research Fund University of Antwerp, Belgium) and from FWO (Brussels, Belgium) projects no. G.0103.04, G.0689.06 and G.0704.08. The staff of the Royal Museum of Fine Arts Antwerp is acknowledged for this pleasant cooperation and the authorisation for the publication of the images in this article. Therefore, a word of gratitude to Paul Huvenne, Yolande Deckers, Stef Antonissen and Gwen Borms. In addition, the authors would like to thank the MOLAB's team operators Chiari Anselmi and Federica Presciutti. MOLAB analyses have been carried out through the support of the EU within the 6th Framework Programme (Contract Eu-ARTECH, RII3-CT-2004-506171). ; |
Approved |
Most recent IF: 3.379; 2011 IF: 3.220 |
| Call Number |
UA @ admin @ c:irua:93680 |
Serial |
5705 |
| Permanent link to this record |
| |
|
| |
| Author |
Alfeld, M.; Janssens, K.; Dik, J.; de Nolf, W.; van der Snickt, G. |
| Title |
Optimization of mobile scanning macro-XRF systems for the in situ investigation of historical paintings |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Journal of analytical atomic spectrometry |
Abbreviated Journal |
J Anal Atom Spectrom |
| Volume |
26 |
Issue |
5 |
Pages |
899-909 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
Elemental distribution maps are of great interest in the study of historical paintings, as they allow to investigate the pigment use of the artist, to image changes made in the painting during or after its creation and in some cases to reveal discarded paintings that were later over painted. Yet a method that allows to record such maps of a broad range of elements in a fast, non-destructive and in situ manner is not yet commonly available; a dedicated mobile scanning XRF instrument might fill this gap. In this paper we present three self-built scanning macro-XRF instruments, each based on the experience gained with its precursor. These instruments are compared in terms of sensitivity and limits of detection, which includes a discussion of the use of polycapillary optics and pinhole collimators as beam defining devices. Furthermore, the imaging capabilities of the instruments are demonstrated in three exemplary cases: (parts of) historical paintings from the 15th to the 19th century are examined. These cases illustrate the value of element specific distribution maps in the study of historical paintings and allow in the case of Vincent van Gogh's Patch of Grass a direct comparison between in situ and synchrotron based scanning macro-XRF. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000289731900004 |
Publication Date |
2011-03-21 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0267-9477 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.379 |
Times cited |
107 |
Open Access |
|
| Notes |
; The investigation of the “Triptych of the Seven Sacraments'' was done in collaboration with Griet Steyaert, independent restorer, and Lizet Klaassen, Royal Museum of Fine Arts (Antwerp, Belgium). The investigation of ”Patch of Grass'' was realized in collaboration with Luuk van der Loeff, Kroller-Muller-Museum (Otterlo, The Netherlands). M. Alfeld is a PhD fellowship of the Research Foundation-Flanders (FWO). This research was supported by the Interuniversity Attraction Poles Programme-Belgian Science Policy (IUAP VI/16) NACHO. The text also presents results of GOA "XANES meets ELNES'' (Research Fund University of Antwerp, Belgium) and from FWO (Brussels, Belgium) projects no. G.0103.04, G.0689.06 and G.0704.08. Further, the work presented was sponsored by the Innovational Research Incentives Scheme of the Netherlands Organization for Scientific Research, NWO (proj. no. 016.118.303). ; |
Approved |
Most recent IF: 3.379; 2011 IF: 3.220 |
| Call Number |
UA @ admin @ c:irua:89919 |
Serial |
5758 |
| Permanent link to this record |
| |
|
| |
| Author |
Janssens, K. |
| Title |
Synchrotron radiation in art and archaeology |
Type |
Editorial |
| Year |
2011 |
Publication |
Journal of analytical atomic spectrometry |
Abbreviated Journal |
J Anal Atom Spectrom |
| Volume |
26 |
Issue |
5 |
Pages |
883-884 |
| Keywords |
Editorial; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
|
| Address |
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| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000289731900001 |
Publication Date |
2011-04-13 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0267-9477 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.379 |
Times cited |
5 |
Open Access |
|
| Notes |
; ; |
Approved |
Most recent IF: 3.379; 2011 IF: 3.220 |
| Call Number |
UA @ admin @ c:irua:89918 |
Serial |
5864 |
| Permanent link to this record |
| |
|
| |
| Author |
Radepont, M.; de Nolf, W.; Janssens, K.; van der Snickt, G.; Coquinot, Y.; Klaassen, L.; Cotte, M. |
| Title |
The use of microscopic X-ray diffraction for the study of HgS and its degradation products corderoite (\alpha-Hg3S2Cl2), kenhsuite (\gamma-Hg3S2Cl2) and calomel (Hg2Cl2) in historical paintings |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Journal of analytical atomic spectrometry |
Abbreviated Journal |
J Anal Atom Spectrom |
| Volume |
26 |
Issue |
5 |
Pages |
959-968 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
Since antiquity, the red pigment mercury sulfide (α-HgS), called cinnabar in its natural form or vermilion red when synthetic, was very often used in frescoes and paintings, even if it was known to suffer occasionally from degradation. The paint hereby acquires a black or silver-grey aspect. The chemical characterization of these alteration products is rather challenging mainly because of the micrometric size and heterogeneity of the surface layers that develop and that are responsible for the color change. Methods such as electron microscopy, synchrotron-based microscopic X-ray fluorescence, microscopic X-ray absorption near edge spectroscopy, Raman microscopy and secondary ion microscopy have been previously employed to identify the (Hg- and S-) compounds present and to study their co-localization. Next to these, also microscopic X-ray diffraction (XRD) (either by making use of laboratory X-ray sources or when used at a synchrotron facility) allows the identification of the crystal phases that are present in degraded HgS paint layers. In this paper we employ these various forms of micro-XRD to analyze degraded red paint in different paintings and compare the results with other X-ray based methods. Whereas the elemental analyses of the degradation products revealed, next to mercury and sulfur, the presence of chlorine, X-ray diffraction allowed the identification, next to α-HgS, of the Hg and S-containing compound calomel (Hg2Cl2) but also of the Hg, S and Cl-containing minerals corderoite (α-Hg3S2Cl2) and kenhsuite (γ-Hg3S2Cl2). These observations are consistent with X-ray absorption spectroscopy measurements performed at the S- and Cl-edges. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000289731900011 |
Publication Date |
2011-03-03 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0267-9477 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.379 |
Times cited |
40 |
Open Access |
|
| Notes |
; The authors gratefully acknowledge GOA programme “XANES meets EELS'' (University of Antwerp Research Council), the IUAP VI/P16 programme ”Nacho'' (BELSPO, Brussels, Belgium) and FWO (Brussels, Belgium) projects no. G.0689.06, G.0704.08 and G017909N for financial support, the ESRF for granting beamtime under proposals no. EC442 and EC720, and Gema Martinez-Criado for practical help on ID18F. The KMSKA staff is also gratefully acknowledged for their help and interest. Javier Chillida is thanked for providing us with the Pedralbes samples. The authors are also indebted to the CHARISMA project (grant agreement 228330) for financial support. ; |
Approved |
Most recent IF: 3.379; 2011 IF: 3.220 |
| Call Number |
UA @ admin @ c:irua:89927 |
Serial |
5896 |
| Permanent link to this record |
| |
|
| |
| Author |
Verbeeck, J.; Schattschneider, P.; Lazar, S.; Stöger-Pollach, M.; Löffler, S.; Steiger-Thirsfeld, A.; Van Tendeloo, G. |
| Title |
Atomic scale electron vortices for nanoresearch |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
| Volume |
99 |
Issue |
20 |
Pages |
203109-203109,3 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Electron vortex beams were only recently discovered and their potential as a probe for magnetism in materials was shown. Here we demonstrate a method to produce electron vortex beams with a diameter of less than 1.2 Å. This unique way to prepare free electrons to a state resembling atomic orbitals is fascinating from a fundamental physics point of view and opens the road for magnetic mapping with atomic resolution in an electron microscope. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos |
000297786500058 |
Publication Date |
2011-11-17 |
| 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 |
90 |
Open Access |
|
| Notes |
Hercules |
Approved |
Most recent IF: 3.411; 2011 IF: 3.844 |
| Call Number |
UA @ lucian @ c:irua:93625UA @ admin @ c:irua:93625 |
Serial |
184 |
| Permanent link to this record |
| |
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| |
| Author |
Houssa, M.; Scalise, E.; Sankaran, K.; Pourtois, G.; Afanas'ev, V.V.; Stesmans, A. |
| Title |
Electronic properties of hydrogenated silicene and germanene |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
| Volume |
98 |
Issue |
22 |
Pages |
223107 |
| Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
| Abstract |
The electronic properties of hydrogenated silicene and germanene, so called silicane and germanane, respectively, are investigated using first-principles calculations based on density functional theory. Two different atomic configurations are found to be stable and energetically degenerate. Upon the adsorption of hydrogen, an energy gap opens in silicene and germanene. Their energy gaps are next computed using the HSE hybrid functional as well as the G(0)W(0) many-body perturbation method. These materials are found to be wide band-gap semiconductors, the type of gap in silicane (direct or indirect) depending on its atomic configuration. Germanane is predicted to be a direct-gap material, independent of its atomic configuration, with an average energy gap of about 3.2 eV, this material thus being potentially interesting for optoelectronic applications in the blue/violet spectral range. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3595682] |
| 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 |
000291405700057 |
Publication Date |
2011-06-03 |
| 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 |
63 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.411; 2011 IF: 3.844 |
| Call Number |
UA @ lucian @ c:irua:105586 |
Serial |
1003 |
| Permanent link to this record |
| |
|
| |
| Author |
Yusupov, M.; Bultinck, E.; Depla, D.; Bogaerts, A. |
| Title |
Elucidating the asymmetric behavior of the discharge in a dual magnetron sputter deposition system |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
| Volume |
98 |
Issue |
13 |
Pages |
131502-131502,3 |
| Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
| Abstract |
A magnetron discharge is characterized by drifts of the charged particles guiding center, caused by the magnetic field, in contrast to unmagnetized discharges. Because of these drifts, a pronounced asymmetry of the discharge can be observed in a dual magnetron setup. In this work, it is found that the shape of the discharge in a dual magnetron configuration depends on the magnetic field configuration. In a closed configuration, strong drifts were observed in one preferential direction, whereas in a mirror configuration the deflection of the discharge was not so pronounced. Our calculations confirm experimental observations. |
| 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 |
000289153600017 |
Publication Date |
2011-04-01 |
| Series Editor |
|
Series Title |
|
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 |
4 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.411; 2011 IF: 3.844 |
| Call Number |
UA @ lucian @ c:irua:87867 |
Serial |
1026 |
| Permanent link to this record |
| |
|
| |
| Author |
Vandenberghe, W.G.; Sorée, B.; Magnus, W.; Groeseneken, G.; Fischetti, M.V. |
| Title |
Impact of field-induced quantum confinement in tunneling field-effect devices |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
| Volume |
98 |
Issue |
14 |
Pages |
143503,1-143503,3 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Being the working principle of a tunnel field-effect transistor, band-to-band tunneling is given a rigorous quantum mechanical treatment to incorporate confinement effects, multiple electron and hole valleys, and interactions with phonons. The model reveals that the strong band bending near the gate dielectric, required to create short tunnel paths, results in quantization of the energy bands. Comparison with semiclassical models reveals a big shift in the onset of tunneling. The effective mass difference of the distinct valleys is found to reduce the subthreshold swing steepness. |
| 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 |
000289297800074 |
Publication Date |
2011-04-06 |
| 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 |
76 |
Open Access |
|
| Notes |
; The authors acknowledge Anne Verhulst for useful discussions. William Vandenberghe gratefully acknowledges the support of a Ph.D. stipend from the Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT-Vlaanderen). This work was supported by IMEC's Industrial Affiliation Program. ; |
Approved |
Most recent IF: 3.411; 2011 IF: 3.844 |
| Call Number |
UA @ lucian @ c:irua:89297 |
Serial |
1559 |
| Permanent link to this record |
| |
|
| |
| Author |
Scalise, E.; Houssa, M.; Pourtois, G.; Afanas'ev, V.V.; Stesmans, A. |
| Title |
Inelastic electron tunneling spectroscopy of HfO2 gate stacks : a study based on first-principles modeling |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
| Volume |
99 |
Issue |
13 |
Pages |
132101,1-132101,3 |
| Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
| Abstract |
A first-principles modeling approach is used to investigate the vibrational properties of HfO2. The calculated phonon density of states is compared to experimental results obtained from inelastic electron tunneling spectroscopy (IETS) of various metal-oxide-semiconductor devices with HfO2 gate stacks. This comparison provides deep insights into the nature of the signatures of the complicated IETS spectra and provides valuable structural information about the gate stack, such as the possible presence of oxygen vacancies in jet-vapour deposited HfO2. Important structural differences between the interface of atomic-layer or molecular-beam deposited HfO2 and the Si substrate are also revealed. |
| Address |
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| Corporate Author |
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Thesis |
|
| Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos |
000295618000036 |
Publication Date |
2011-09-26 |
| 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 |
1 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.411; 2011 IF: 3.844 |
| Call Number |
UA @ lucian @ c:irua:93611 |
Serial |
1606 |
| Permanent link to this record |
| |
|
| |
| Author |
Sorée, B.; Magnus, W.; Vandenberghe, W. |
| Title |
Low-field mobility in ultrathin silicon nanowire junctionless transistors |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
| Volume |
99 |
Issue |
23 |
Pages |
233509-233509,3 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We theoretically investigate the phonon, surface roughness and ionized impurity limited low-field mobility of ultrathin silicon n-type nanowire junctionless transistors in the long channel approximation with wire radii ranging from 2 to 5 nm, as function of gate voltage. We show that surface roughness scattering is negligible as long as the wire radius is not too small and ionized impurity scattering is the dominant scattering mechanism. We also show that there exists an optimal radius where the ionized impurity limited mobility exhibits a maximum. |
| 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 |
000298006100095 |
Publication Date |
2011-12-09 |
| 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 |
20 |
Open Access |
|
| Notes |
; This work is supported by the EU project SQWIRE (FP7-ICT-STREP nr. 257111). William Vandenberghe gratefully acknowledges the Ph.D. stipend from the Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT-Vlaanderen). ; |
Approved |
Most recent IF: 3.411; 2011 IF: 3.844 |
| Call Number |
UA @ lucian @ c:irua:92865 |
Serial |
1850 |
| Permanent link to this record |
| |
|
| |
| Author |
Kalkert, C.; Krisponeit, J.-O.; Esseling, M.; Lebedev, O.I.; Moshnyaga, V.; Damaschke, B.; Van Tendeloo, G.; Samwer, K. |
| Title |
Resistive switching at manganite/manganite interfaces |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
| Volume |
99 |
Issue |
13 |
Pages |
132512-132512,3 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
We report bipolar resistive switching between the interfaces of manganite nanocolumns. La0.7Sr0.3MnO3 films were prepared on Al2O3 substrates, where the films grow in nanocolumns from the substrate to the surface. Conductive atomic force microscopy directly detects that the resistive switching is located at the boundaries of the grains. Furthermore, mesoscopic transport measurements reveal a tunnel magnetoresistance. In combination with the resistive switching, this leads to a total of four different resistive states. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos |
000295618000052 |
Publication Date |
2011-09-29 |
| 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 |
10 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.411; 2011 IF: 3.844 |
| Call Number |
UA @ lucian @ c:irua:91884 |
Serial |
2881 |
| Permanent link to this record |
| |
|
| |
| Author |
Wu, Z.; Peeters, F.M.; Chang, K. |
| Title |
Spin and momentum filtering of electrons on the surface of a topological insulator |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
| Volume |
98 |
Issue |
16 |
Pages |
162101,1-162101,3 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We investigate theoretically the transport properties of Dirac fermions on the surface of a three-dimensional topological insulator. Dirac electrons can be totally reflected in front of a magnetic/electric p-n junction. For a p-n-p structure, multiple total internal reflections at the interfaces result in the bound states in the channel, which behaves like an electronic waveguide. This p-n-p like structure exhibits spin and momentum filtering features and could be used as a spin and/or charge diode. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos |
000289842700032 |
Publication Date |
2011-04-18 |
| 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 |
33 |
Open Access |
|
| Notes |
; ; |
Approved |
Most recent IF: 3.411; 2011 IF: 3.844 |
| Call Number |
UA @ lucian @ c:irua:89971 |
Serial |
3076 |
| Permanent link to this record |
| |
|
| |
| Author |
Scalise, E.; Houssa, M.; Pourtois, G.; Afanas'ev, V.V.; Stesmans, A. |
| Title |
Structural and vibrational properties of amorphous GeO2 from first-principles |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
| Volume |
98 |
Issue |
20 |
Pages |
202110,1-202110,3 |
| Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
| Abstract |
The structural and vibrational properties of amorphous germanium oxide (a-GeO<sub>2</sub>) are investigated using first-principles calculations based on density functional theory. We first generate an a-GeO<sub>2</sub> structure by first-principles molecular dynamics and analyze its structural properties. The vibrational spectra is then calculated within a density-functional approach. Both static and dynamic properties are in good agreement with experimental data. We next generate defects in our structure (oxygen vacancies with several density and charge states) and consider the most stable atomic configurations, focusing on the vibrational features of threefold coordinated O and divalent Ge centers. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos |
000290812100038 |
Publication Date |
2011-05-20 |
| 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 |
226 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.411; 2011 IF: 3.844 |
| Call Number |
UA @ lucian @ c:irua:90222 |
Serial |
3202 |
| Permanent link to this record |
| |
|
| |
| 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 |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos |
000286009800055 |
Publication Date |
2011-01-07 |
| 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 |
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 |
| |
|
| |
| Author |
Nasirpouri, F.; Engbarth, M.A.; Bending, S.J.; Peter, L.M.; Knittel, A.; Fangohr, H.; Milošević, M.V. |
| Title |
Three-dimensional ferromagnetic architectures with multiple metastable states |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
| Volume |
98 |
Issue |
22 |
Pages |
222506,1-222506,3 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We demonstrate controllable dual-bath electrodeposition of nickel on architecture-tunable three-dimensional (3D) silver microcrystals. Magnetic hysteresis loops of individual highly faceted Ag-Ni core-shell elements reveal magnetization reversal that comprises multiple sharp steps corresponding to different stable magnetic states. Finite-element micromagnetic simulations on smaller systems show several jumps during magnetization reversal which correspond to transitions between different magnetic vortex states. Structures of this type could be realizations of an advanced magnetic data storage architecture whereby each element represents one multibit, storing a combination of several conventional bits depending on the overall number of possible magnetic states associated with the 3D core-shell shape. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos |
000291405700044 |
Publication Date |
2011-06-03 |
| 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 |
; This work was supported by EPSRC in the U.K. under Grant Nos. EP/E039944/1 and EP/E040063/1, DYNAMAG project (EU FP7/2007-2013 Grant No. 233552), and FWO-Vlaanderen. ; |
Approved |
Most recent IF: 3.411; 2011 IF: 3.844 |
| Call Number |
UA @ lucian @ c:irua:90008 |
Serial |
3652 |
| Permanent link to this record |
| |
|
| |
| Author |
Liu, Y.; Cheng, F.; Li, X.J.; Peeters, F.M.; Chang, K. |
| Title |
Tuning of anisotropy in two-electron quantum dots by spin-orbit interactions |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
| Volume |
99 |
Issue |
3 |
Pages |
032102,1-032102,3 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We investigate the influence of the spin-orbit interactions (SOIs) on the electron distribution and the optical absorption of a two-electron quantum dot. It is shown that the interplay between the SOIs makes the two-electron quantum dot behave like two laterally coupled quantum dots and the anisotropic distribution can be rotated from [110] to [11®0] by reversing the direction of the perpendicular electric field and detect it through the optical absorption spectrum. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos |
000293679000026 |
Publication Date |
2011-07-18 |
| 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 |
; This work was supported by NSFC Grants No. 16760525405, 10874175 and 11004017 and the Belgian Science Policy 168(IAP). ; |
Approved |
Most recent IF: 3.411; 2011 IF: 3.844 |
| Call Number |
UA @ lucian @ c:irua:92473 |
Serial |
3749 |
| Permanent link to this record |
| |
|
| |
| Author |
Peelaers, H.; Hernández-Nieves, A.D.; Leenaerts, O.; Partoens, B.; Peeters, F.M. |
| Title |
Vibrational properties of graphene fluoride and graphane |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
| Volume |
98 |
Issue |
5 |
Pages |
051914 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The vibrational properties of graphene fluoride and graphane are studied using ab initio calculations. We find that both sp(3) bonded derivatives of graphene have different phonon dispersion relations and phonon densities of states as expected from the different masses associated with the attached atoms of fluorine and hydrogen, respectively. These differences manifest themselves in the predicted temperature behavior of the constant-volume specific heat of both compounds. (C) 2011 American Institute of Physics. [doi:10.1063/1.3551712] |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos |
000286988400027 |
Publication Date |
2011-02-02 |
| 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 |
66 |
Open Access |
|
| Notes |
; This work was supported by the Flemish Science Foundation (FWO-V1), the Belgian Science Policy (IAP), and the collaborative project FWO-MINCyT (Contract No. FW /08/01). A.D.H.-N. is also supported by ANPCyT (under Grant No. PICT2008-2236) ; |
Approved |
Most recent IF: 3.411; 2011 IF: 3.844 |
| Call Number |
UA @ lucian @ c:irua:105604 |
Serial |
3844 |
| Permanent link to this record |
| |
|
| |
| Author |
Cooper, D.; Rouvière, J.-L.; Béché, A.; Kadkhodazadeh, S.; Semenova, E.S.; Dunin-Borkowsk, R. |
| Title |
Quantitative strain mapping of InAs/InP quantum dots with 1 nm spatial resolution using dark field electron holography |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
| Volume |
99 |
Issue |
|
Pages |
261911-261913 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
The optical properties of semiconductor quantum dots are greatly influenced by their strain state. Dark field electron holography has been used to measure the strain in InAsquantum dotsgrown in InP with a spatial resolution of 1 nm. A strain value of 5.4% ± 0.1% has been determined which is consistent with both measurements made by geometrical phase analysis of high angle annular dark field scanning transmission electron microscopy images and with simulations. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos |
000298638500027 |
Publication Date |
2012-01-03 |
| 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 |
26 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.411; 2011 IF: 3.844 |
| Call Number |
UA @ lucian @ c:irua:136428 |
Serial |
4507 |
| Permanent link to this record |
| |
|
| |
| Author |
Simon, Q.; Barreca, D.; Bekermann, D.; Gasparotto, A.; Maccato, C.; Comini, E.; Gombac, V.; Fornasiero, P.; Lebedev, O.I.; Turner, S.; Devi, A.; Fischer, R.A.; Van Tendeloo, G. |
| Title |
Plasma-assisted synthesis of Ag/ZnO nanocomposites : first example of photo-induced H2 production and sensing |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
International journal of hydrogen energy |
Abbreviated Journal |
Int J Hydrogen Energ |
| Volume |
36 |
Issue |
24 |
Pages |
15527-15537 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Ag/ZnO nanocomposites were developed by a plasma-assisted approach. The adopted strategy exploits the advantages of Plasma Enhanced-Chemical Vapor Deposition (PE-CVD) for the growth of columnar ZnO arrays on Si(100) and Al2O3 substrates, in synergy with the infiltration power of the Radio Frequency (RF)-sputtering technique for the subsequent dispersion of different amounts of Ag nanoparticles (NPs). The resulting composites, both as-prepared and after annealing in air, were thoroughly characterized with particular attention on their morphological organization, structure and composition. For the first time, the above systems have been used as catalysts in the production of hydrogen by photo-reforming of alcoholic solutions, yielding a stable H2 evolution even by the sole use of simulated solar radiation. In addition, Ag/ZnO nanocomposites presented an excellent response in the gas-phase detection of H2, opening attractive perspectives for advanced technological applications. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Oxford |
Editor |
|
| Language |
|
Wos |
000297089700006 |
Publication Date |
2011-10-14 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0360-3199; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.582 |
Times cited |
62 |
Open Access |
|
| Notes |
Esteem 026019; Fwo |
Approved |
Most recent IF: 3.582; 2011 IF: 4.054 |
| Call Number |
UA @ lucian @ c:irua:91901 |
Serial |
2627 |
| Permanent link to this record |
| |
|
| |
| Author |
de Clippel, F.; Harkiolakis, A.; Vosch, T.; Ke, X.; Giebeler, L.; Oswald, S.; Houthoofd, K.; Jammaer, J.; Van Tendeloo, G.; Martens, J.A.; Jacobs, P.A.; Baron, G.V.; Sels, B.F.; Denayer, J.F.M. |
| Title |
Graphitic nanocrystals inside the pores of mesoporous silica : synthesis, characterization and an adsorption study |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Microporous and mesoporous materials: zeolites, clays, carbons and related materials |
Abbreviated Journal |
Micropor Mesopor Mat |
| Volume |
144 |
Issue |
1/3 |
Pages |
120-133 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
This work presents a new carbonsilica hybrid material, denoted as CSM, with remarkable sorption properties. It consists of intraporous graphitic nanocrystals grown in the pores of mesoporous silica. CSM is obtained by a subtle incipient wetness impregnation of Al-containing mesoporous silica with furfuryl alcohol (FA)/hemelitol solutions. Both the volume match of the impregnation solution with that of the silica template pore volume, and the presence of Al3+ in the silica, are crucial to polymerize FA selectively inside the mesopores. Carbonization of the intraporous polymer was then performed by pyrolysis under He up to 1273 K. The resulting CSMs were examined by SEM, HRTEM, 27Al MAS NMR, N2 adsorption, XRD, TGA, TPD, XPS, pycnometry and Raman spectroscopy. Mildly oxidized graphitic-like carbon nanoblocks, consisting of a few graphene-like sheets, were thus identified inside the template mesopores. Random stacking of these carbon crystallites generates microporosity resulting in biporous materials at low carbon content and microporous materials at high carbon loadings. Very narrow pore distributions were obtained when pyrolysis was carried out under slow heating rate, viz. 1 K min−1. Adsorption and shape selective properties of the carbon filled mesoporous silica were studied by performing pulse chromatography and breakthrough experiments, and by measuring adsorption isotherms of linear and branched alkanes. Whereas the parent mesoporous silica shows unselective adsorption, their CSM analogues preferentially adsorb linear alkanes. The sorption capacity and selectivity can be adjusted by changing the pore size of the template or by varying the synthesis conditions. A relation between the carbon crystallites size and the shape selective behaviour of the corresponding CSM for instance is demonstrated. Most interestingly, CSM shows separation factors for linear and branched alkanes up to values comparable to those of zeolitic molecular sieves. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000293435400016 |
Publication Date |
2011-04-15 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1387-1811; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.615 |
Times cited |
15 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.615; 2011 IF: 3.285 |
| Call Number |
UA @ lucian @ c:irua:92325 |
Serial |
1380 |
| Permanent link to this record |
| |
|
| |
| Author |
Fang, C.M.; van Huis, M.A.; Zandbergen, H.W. |
| Title |
Stability and structures of the \epsilon-phases of iron nitrides and iron carbides from first principles |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Scripta materialia |
Abbreviated Journal |
Scripta Mater |
| Volume |
64 |
Issue |
3 |
Pages |
296-299 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
First-principles calculations were performed for the ε-phases and other iron carbides/nitrides with hexagonal close-packed Fe sublattices. Although these nitrides/carbides have similar crystal structures, they exhibit different chemical and physical properties. Relative to α-Fe, graphite and N2, all the ε-type nitrides are stable, while all the carbides are metastable. The lattice parameters of the ε-iron nitrides vary differently from those of the ε-carbides, as a function of the concentration of X (Xdouble bond; length as m-dashN, C). The structural relationships of ε-Fe2X with η-Fe2X and ζ-Fe2X are discussed. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Oxford |
Editor |
|
| Language |
|
Wos |
000285323300022 |
Publication Date |
2010-09-02 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1359-6462; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.747 |
Times cited |
29 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.747; 2011 IF: 2.699 |
| Call Number |
UA @ lucian @ c:irua:86974 |
Serial |
3120 |
| Permanent link to this record |
| |
|
| |
| Author |
Yusupov, M.; Bultinck, E.; Depla, D.; Bogaerts, A. |
| Title |
Behavior of electrons in a dual-magnetron sputter deposition system : a Monte Carlo model |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
New journal of physics |
Abbreviated Journal |
New J Phys |
| Volume |
13 |
Issue |
|
Pages |
033018-033018,17 |
| Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
| Abstract |
A Monte Carlo model has been developed for investigating the electron behavior in a dual-magnetron sputter deposition system. To describe the three-dimensional (3D) geometry, different reference frames, i.e. a local and a global coordinate system, were used. In this study, the influence of both closed and mirror magnetic field configurations on the plasma properties is investigated. In the case of a closed magnetic field configuration, the calculated electron trajectories show that if an electron is emitted in (or near) the center of the cathode, where the influence of the magnetic field is low, it is able to travel from one magnetron to the other. On the other hand, when an electron is created at the race track area, it is more or less trapped in the strong magnetic field and cannot easily escape to the second magnetron region. In the case of a mirror magnetic field configuration, irrespective of where the electron is emitted from the cathode, it cannot travel from one magnetron to the other because the magnetic field lines guide the electron to the substrate. Moreover, the electron density and electron impact ionization rate have been calculated and studied in detail for both configurations. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Bristol |
Editor |
|
| Language |
|
Wos |
000289064600001 |
Publication Date |
2011-03-15 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1367-2630; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.786 |
Times cited |
12 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.786; 2011 IF: 4.177 |
| Call Number |
UA @ lucian @ c:irua:87544 |
Serial |
224 |
| Permanent link to this record |
| |
|
| |
| Author |
Dixit, H.; Tandon, N.; Cottenier, S.; Saniz, R.; Lamoen, D.; Partoens, B.; van Speybroeck, V.; Waroquier, M. |
| Title |
Electronic structure and band gap of zinc spinel oxides beyond LDA : ZnAl2O4, ZnGa2O4 and ZnIn2O4 |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
New journal of physics |
Abbreviated Journal |
New J Phys |
| Volume |
13 |
Issue |
6 |
Pages |
063002-063002,11 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
| Abstract |
We examine the electronic structure of the family of ternary zinc spinel oxides ZnX2O4 (X=Al, Ga and In). The band gap of ZnAl2O4 calculated using density functional theory (DFT) is 4.25 eV and is overestimated compared with the experimental value of 3.83.9 eV. The DFT band gap of ZnGa2O4 is 2.82 eV and is underestimated compared with the experimental value of 4.45.0 eV. Since DFT typically underestimates the band gap in the oxide system, the experimental measurements for ZnAl2O4 probably require a correction. We use two first-principles techniques capable of describing accurately the excited states of semiconductors, namely the GW approximation and the modified BeckeJohnson (MBJ) potential approximation, to calculate the band gap of ZnX2O4. The GW and MBJ band gaps are in good agreement with each other. In the case of ZnAl2O4, the predicted band gap values are >6 eV, i.e. ~2 eV larger than the only reported experimental value. We expect future experimental work to confirm our results. Our calculations of the electron effective masses and the second band gap indicate that these compounds are very good candidates to act as transparent conducting host 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 |
Bristol |
Editor |
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| Language |
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Wos |
000292137500002 |
Publication Date |
2011-06-03 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1367-2630; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.786 |
Times cited |
98 |
Open Access |
|
| Notes |
Iwt; Fwo; Bof-Noi |
Approved |
Most recent IF: 3.786; 2011 IF: 4.177 |
| Call Number |
UA @ lucian @ c:irua:89555 |
Serial |
1008 |
| Permanent link to this record |
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| |
| Author |
Vernimmen, J.; Guidotti, M.; Silvestre-Albero, J.; Jardim, E.O.; Mertens, M.; Lebedev, O.I.; Van Tendeloo, G.; Psaro, R.; Rodríguez-Reinoso, F.; Meynen, V.; Cool, P. |
| Title |
Immersion calorimetry as a tool to evaluate the catalytic performance of titanosilicate materials in the epoxidation of cyclohexene |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Langmuir: the ACS journal of surfaces and colloids |
Abbreviated Journal |
Langmuir |
| Volume |
27 |
Issue |
7 |
Pages |
3618-3625 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA) |
| Abstract |
Different types of titanosilicates are synthesized, structurally characterized, and subsequently catalytically tested in the liquid-phase epoxidation of cyclohexene. The performance of three types of combined zeolitic/mesoporous materials is compared with that of widely studied Ti-grafted-MCM-41 molecular sieve and the TS-1 microporous titanosilicate. The catalytic test results are correlated with the structural characteristics of the different catalysts. Moreover, for the first time, immersion calorimetry with the same substrate molecule as in the catalytic test reaction is applied as an extra means to interpret the catalytic results. A good correlation between catalytic performance and immersion calorimetry results is found. This work points out that the combination of catalytic testing and immersion calorimetry can lead to important insights into the influence of the materials structural characteristics on catalysis. Moreover, the potential of using immersion calorimetry as a screening tool for catalysts in epoxidation reactions is shown. |
| 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 |
000288970900054 |
Publication Date |
2011-02-23 |
| 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 |
|
Edition |
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| ISSN |
0743-7463;1520-5827; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.833 |
Times cited |
19 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.833; 2011 IF: 4.186 |
| Call Number |
UA @ lucian @ c:irua:88366 |
Serial |
1557 |
| Permanent link to this record |
| |
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| |
| Author |
Barreca, D.; Carraro, G.; Gasparotto, A.; Maccato, C.; Lebedev, O.I.; Parfenova, A.; Turner, S.; Tondello, E.; Van Tendeloo, G. |
| Title |
Tailored vapor-phase growth of CuxO-TiO2(x=1,2) nanomaterials decorated with Au particles |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Langmuir: the ACS journal of surfaces and colloids |
Abbreviated Journal |
Langmuir |
| Volume |
27 |
Issue |
10 |
Pages |
6409-6417 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
We report on the fabrication of CuxOTiO2 (x = 1, 2) nanomaterials by an unprecedented vapor-phase approach. The adopted strategy involves the growth of porous CuxO matrices by means of chemical vapor deposition (CVD), followed by the controlled dispersion of TiO2 nanoparticles. The syntheses are performed on Si(100) substrates at temperatures of 400550 °C under wet oxygen atmospheres, adopting Cu(hfa)2·TMEDA (hfa =1,1,1,5,5,5-hexafluoro-2,4-pentanedionate; TMEDA = N,N,N′,N′-tetramethylethylenediamine) and Ti(O-iPr)2(dpm)2 (O-iPr = isopropoxy; dpm = 2,2,6,6-tetramethyl-3,5-heptanedionate) as copper and titanium precursors, respectively. Subsequently, finely dispersed gold nanoparticles are introduced in the as-prepared systems via radio frequency (RF)-sputtering under mild conditions. The synthesis process results in the formation of systems with chemical composition and nano-organization strongly dependent on the nature of the initial CuxO matrix and on the deposited TiO2 amount. The decoration with low-size gold clusters paves the way to the engineering of hierarchically organized nanomaterials. |
| 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 |
000290292900082 |
Publication Date |
2011-04-25 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
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| ISSN |
0743-7463;1520-5827; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.833 |
Times cited |
36 |
Open Access |
|
| Notes |
Fwo |
Approved |
Most recent IF: 3.833; 2011 IF: 4.186 |
| Call Number |
UA @ lucian @ c:irua:88940 |
Serial |
3467 |
| Permanent link to this record |
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| |
| Author |
Matulis, A.; Masir, M.R.; Peeters, F.M. |
| Title |
Application of optical beams to electrons in graphene |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
83 |
Issue |
11 |
Pages |
115458-115458,7 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The technique of beam optics is applied to the description of the wave function of Dirac electrons. This approach is illustrated by considering electron transmission through simple nonhomogeneous structures, such as flat and bent p-n junctions and superlattices. We found that a convex p-n junction compresses the beam waist, while a concave interface widens it without loosing its focusing properties. At a flat p-n junction the waist of the transmitted Gaussian beam can be narrowed or widened, depending on the angle of incidence. A general condition is derived for the occurrence of beam collimation in a superlattice which is less stringent than previous 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 |
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Editor |
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| Language |
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Wos |
000288896400013 |
Publication Date |
2011-03-29 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
13 |
Open Access |
|
| Notes |
; This research was supported by the Flemish Science Foundation (Grant No. FWO-Vl), by the Belgian Science policy (IAP), and (in part) by the Lithuanian Science Council under project No. MIP-79/2010. ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
| Call Number |
UA @ lucian @ c:irua:89377 |
Serial |
142 |
| Permanent link to this record |
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| |
| Author |
Zarenia, M.; Pereira, J.M.; Farias, G.A.; Peeters, F.M. |
| Title |
Chiral states in bilayer graphene : magnetic field dependence and gap opening |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
84 |
Issue |
12 |
Pages |
125451-125451,13 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
At the interface of electrostatic potential kink profiles, one-dimensional chiral states are found in bilayer graphene (BLG). Such structures can be created by applying an asymmetric potential to the upper and the lower layers of BLG. We found the following: (i) due to the strong confinement by the single kink profile, the unidirectional states are only weakly affected by a magnetic field; (ii) increasing the smoothness of the kink potential results in additional bound states, which are topologically different from those chiral states; and (iii) in the presence of a kink-antikink potential, the overlap between the oppositely moving chiral states results in the appearance of crossing and anticrossing points in the energy spectrum. This leads to the opening of tunable minigaps in the spectrum of the unidirectional topological states. |
| 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 |
000295484300016 |
Publication Date |
2011-09-30 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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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 |
50 |
Open Access |
|
| Notes |
; This work was supported by the Flemish Science Foundation (FWO-VI), the Belgian Science Policy (IAP), the European Science Foundation (ESF) under the EUROCORES program EuroGRAPHENE (project CONGRAN), the Brazilian agency CNPq (Pronex), and the bilateral projects between Flanders and Brazil and the collaboration project FWO-CNPq. ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
| Call Number |
UA @ lucian @ c:irua:92915 |
Serial |
358 |
| Permanent link to this record |
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| |
| Author |
Chaves, A.; Komendová, L.; Milošević, M.V.; Andrade, J.S.; Farias, G.A.; Peeters, F.M. |
| Title |
Conditions for nonmonotonic vortex interaction in two-band superconductors |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
83 |
Issue |
21 |
Pages |
214523-214523,6 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We describe a semianalytic approach to the two-band Ginzburg-Landau theory, which predicts the behavior of vortices in two-band superconductors. We show that the character of the short-range vortex-vortex interaction is determined by the sign of the normal domain-superconductor interface energy, in analogy with the conventional differentiation between type I and type II superconductors. However, we also show that the long-range interaction is determined by a modified Ginzburg-Landau parameter κ*, different from the standard κ of a bulk superconductor. This opens the possibility for nonmonotonic vortex-vortex interaction, which is temperature dependent, and can be further tuned by alterations of the material on the microscopic scale. |
| 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 |
000292252300009 |
Publication Date |
2011-06-30 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1098-0121;1550-235X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
46 |
Open Access |
|
| Notes |
; Discussions with A. Moreira, A. Shanenko, R. Prozorov, and A. Golubov are gratefully acknowledged. This work was supported by the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), the bilateral project FWO-CNPq, CAPES, and PRONEX/CNPq/FUNCAP. ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
| Call Number |
UA @ lucian @ c:irua:90922 |
Serial |
477 |
| Permanent link to this record |
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| Author |
Peelaers, H.; Partoens, B.; Giantomassi, M.; Rangel, T.; Goossens, E.; Rignanese, G.-M.; Gonze, X.; Peeters, F.M. |
| Title |
Convergence of quasiparticle band structures of Si and Ge nanowires in the GW approximation and the validity of scissor shifts |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
83 |
Issue |
4 |
Pages |
045306-045306,6 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Starting from fully converged density-functional theory calculations, the quasiparticle corrections are calculated for different sized Si and Ge nanowires using the GW approximation. The effectiveness of recently developed techniques in speeding up the convergence of the quasiparticle calculations is demonstrated. The complete quasiparticle band structures are also obtained using an interpolation technique based on maximallylocalized Wannier functions. From the quasiparticle results, we assess the correctness of the commonly applied scissor-shift correction. Dispersion changes are observed, which are also reflected in changes in the effective band masses calculated taking into account quasiparticle corrections. |
| 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 |
000286771400004 |
Publication Date |
2011-01-21 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1098-0121;1550-235X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
18 |
Open Access |
|
| Notes |
; We are grateful to Yann Pouillon for valuable technical support with the build system of ABINIT, related to the WANNIER90 library. This work was supported by the Flemish Science Foundation (FWO-Vl) and by the Interuniversity Attraction Poles Program (P6/42)-Belgian State-Belgian Science Policy. X. G. and G.-M. R. acknowledge funding from the EU's 7th Framework Programme through the ETSF I3 e-Infrastructure project (Grant No. 211956), the Communaute francaise de Belgique through the Action de Recherche Concertee 07/12-003 “Nanosystemes hybrides metal-organiques,” and the Wallon Region Project No. 816849 “ European Theoretical Spectroscopy Facility” (WALL ETSF). M. G. acknowledges funding from the FRFC Project No. 2.4.589.09.F. ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
| Call Number |
UA @ lucian @ c:irua:86905 |
Serial |
510 |
| Permanent link to this record |
