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Author |
Galván Moya, J.E.; Nelissen, K.; Peeters, F.M. |
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Title |
Structural transitions in vertically and horizontally coupled parabolic channels of Wigner crystals |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
86 |
Issue |
18 |
Pages |
184102-184109 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Structural phase transitions in two vertically or horizontally coupled channels of strongly interacting particles are investigated. The particles are free to move in the x direction but are confined by a parabolic potential in the y direction. They interact with each other through a screened power-law potential (r(-n)e(-r/lambda)). In vertically coupled systems, the channels are stacked above each other in the direction perpendicular to the (x, y) plane, while in horizontally coupled systems both channels are aligned in the confinement direction. Using Monte Carlo (MC) simulations we obtain the ground-state configurations and the structural transitions as a function of the linear particle density and the separation between the channels. At zero temperature, the vertically coupled system exhibits a rich phase diagram with continuous and discontinuous transitions. On the other hand, the horizontally coupled system exhibits only a very limited number of phase transitions due to its symmetry. Further, we calculated the normal modes for the Wigner crystals in both cases. From MC simulations, we found that in the case of vertically coupled systems, the zigzag transition is only possible for low densities. A Ginzburg-Landau theory for the zigzag transition is presented, which predicts correctly the behavior of this transition from which we interpret the structural phase transition of the Wigner crystal through the reduction of the Brillouin zone. |
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Wos |
000310683600002 |
Publication Date |
2012-11-05 |
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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 |
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Impact Factor |
3.836 |
Times cited |
6 |
Open Access |
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Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl). ; |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
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Call Number |
UA @ lucian @ c:irua:105150 |
Serial |
3271 |
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Author |
Muñoz, W.A.; Covaci, L.; Peeters, F.M. |
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Title |
Tight-binding study of bilayer graphene Josephson junctions |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
86 |
Issue |
18 |
Pages |
184505-184507 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Using highly efficient simulations of the tight-binding Bogoliubov-de-Gennes model, we solved self-consistently for the pair correlation and the Josephson current in a superconducting-bilayer graphene-superconducting Josephson junction. Different doping levels for the non-superconducting link are considered in the short- and long-junction regimes. Self-consistent results for the pair correlation and superconducting current resemble those reported previously for single-layer graphene except at the Dirac point, where remarkable differences in the proximity effect are found, as well as a suppression of the superconducting current in the long-junction regime. Inversion symmetry is broken by considering a potential difference between the layers and we found that the supercurrent can be switched if the junction length is larger than the Fermi length. |
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Wos |
000310840400005 |
Publication Date |
2012-11-07 |
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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 |
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Impact Factor |
3.836 |
Times cited |
13 |
Open Access |
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Notes |
; This work was supported by the Flemish Science Foundation (FWO-VI). ; |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
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Call Number |
UA @ lucian @ c:irua:105149 |
Serial |
3661 |
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Author |
Ati, M.; Sathiya, M.; Boulineau, S.; Reynaud, M.; Abakumov, A.; Rousse, G.; Melot, B.; Van Tendeloo, G.; Tarascon, J.-M. |
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Title |
Understanding and promoting the rapid preparation of the triplite-phase of LiFeSO4F for use as a large-potential Fe cathode |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
Journal of the American Chemical Society |
Abbreviated Journal |
J Am Chem Soc |
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Volume |
134 |
Issue |
44 |
Pages |
18380-18387 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The development of new electrode materials, which are composed of Earth-abundant elements and that can be made via eco-efficient processes, is becoming absolutely necessary for reasons of sustainable production. The 3.9 V triplite-phase of LiFeSO4F, compared to the 3.6 V tavorite-phase, could satisfy this requirement provided the currently complex synthetic pathway can be simplified. Here, we present our work aiming at better understanding the reaction mechanism that govern its formation as a way to optimize its preparation. We first demonstrate, using complementary X-ray diffraction and transmission electron microscopy studies, that triplite-LiFeSO4F can nucleate from tavorite-LiFeSO4F via a reconstructive process whose kinetics are significantly influenced by moisture and particle morphology. Perhaps the most spectacular finding is that it is possible to prepare electrochemically active triplite-LiFeSO4F from anhydrous precursors using either reactive spark plasma sintering (SPS) synthesis in a mere 20 min at 320 degrees C or room temperature ball milling for 3 h. These new pathways appear to be strongly driven by the easy formation of a disordered phase with higher entropy, as both techniques trigger disorder via rapid annealing steps or defect creation. Although a huge number of phases adopts the tavorite structure-type, this new finding offers both a potential way to prepare new compositions in the triplite structure and a wealth of opportunities for the synthesis of new materials which could benefit many domains beyond energy storage. |
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Place of Publication |
Washington, D.C. |
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Wos |
000310720900041 |
Publication Date |
2012-10-12 |
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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 |
0002-7863;1520-5126; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
13.858 |
Times cited |
36 |
Open Access |
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Notes |
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Approved |
Most recent IF: 13.858; 2012 IF: 10.677 |
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Call Number |
UA @ lucian @ c:irua:105147 |
Serial |
3802 |
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Author |
Retuerto, M.; Li, M.R.; Go, Y.B.; Ignatov, A.; Croft, M.; Ramanujachary, K.V.; Hadermann, J.; Hodges, J.P.; Herber, R.H.; Nowik, I.; Greenblatt, M.; |
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Title |
Magnetic and structural studies of the multifunctional material SrFe0.75Mo0.25O3-\text{\textgreek{d}} |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
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Volume |
51 |
Issue |
22 |
Pages |
12273-12280 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
SrFe0.75Mo0.25O3-delta has been recently discovered as an extremely efficient electrode for intermediate temperature solid oxide fuel cells (IT-SOFCs). We have performed structural and magnetic studies to fully characterize this multifunctional material. We have observed by powder neutron diffraction (PND) and transmission electron microscopy (TEM) that its crystal symmetry is better explained with a tetragonal symmetry (I4/mcm space group) than with the previously reported orthorhombic symmetry (Pnma space group). The temperature dependent magnetic properties indicate an exceptionally high magnetic ordering temperature (T-N similar to 750 K), well above room temperature. The ordered magnetic structure at low temperature was determined by PND to be an antiferromagnetic coupling of the Fe cations. Mossbauer spectroscopy corroborated the PND results. A detailed study, with X-ray absorption spectroscopy (XAS), in agreement with the Mossbauer results, confirmed the formal oxidation states of the cations to be mixed valence Fe3+/4+ and Mo6+. |
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Place of Publication |
Easton, Pa |
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Wos |
000311173700024 |
Publication Date |
2012-10-26 |
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Abbreviated Series Title |
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ISSN |
0020-1669;1520-510X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.857 |
Times cited |
12 |
Open Access |
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Notes |
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Approved |
Most recent IF: 4.857; 2012 IF: 4.593 |
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Call Number |
UA @ lucian @ c:irua:105142 |
Serial |
1862 |
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Author |
Bittencourt, C.; Krüger, P.; Lagos, M.J.; Ke, X.; Van Tendeloo, G.; Ewels, C.; Umek, P.; Guttmann, P. |
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Title |
Towards atomic resolution in sodium titanate nanotubes using near-edge X-ray-absorption fine-structure spectromicroscopy combined with multichannel multiple-scattering calculations |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
Beilstein journal of nanotechnology |
Abbreviated Journal |
Beilstein J Nanotech |
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Volume |
3 |
Issue |
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Pages |
789-797 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
Recent advances in near-edge X-ray-absorption fine-structure spectroscopy coupled with transmission X-ray microscopy (NEXAFS-TXM) allow large-area mapping investigations of individual nano-objects with spectral resolution up to E/Delta E = 104 and spatial resolution approaching 10 nm. While the state-of-the-art spatial resolution of X-ray microscopy is limited by nanostructuring process constrains of the objective zone plate, we show here that it is possible to overcome this through close coupling with high-level theoretical modelling. Taking the example of isolated bundles of hydrothermally prepared sodium titanate nanotubes ((Na,H)TiNTs) we are able to unravel the complex nanoscale structure from the NEXAFS-TXM data using multichannel multiple-scattering calculations, to the extent of being able to associate specific spectral features in the O K-edge and Ti L-edge with oxygen atoms in distinct sites within the lattice. These can even be distinguished from the contribution of different hydroxyl groups to the electronic structure of the (Na,H)TiNTs. |
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Wos |
000311482400001 |
Publication Date |
2012-11-23 |
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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 |
2190-4286; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.127 |
Times cited |
13 |
Open Access |
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Notes |
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Approved |
Most recent IF: 3.127; 2012 IF: 2.374 |
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Call Number |
UA @ lucian @ c:irua:105140 |
Serial |
3684 |
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Author |
Beheshtian, J.; Sadeghi, A.; Neek-Amal, M.; Michel, K.H.; Peeters, F.M. |
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Title |
Induced polarization and electronic properties of carbon-doped boron nitride nanoribbons |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
86 |
Issue |
19 |
Pages |
195433-195438 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The electronic properties of boron nitride nanoribbons (BNNRs) doped with a line of carbon atoms are investigated using density functional calculations. By replacing a line of alternating B and N atoms with carbons, three different configurations are possible depending on the type of the atoms which bond to the carbons. We found very different electronic properties for these configurations: (i) the NCB arrangement is strongly polarized with a large dipole moment having an unexpected direction, (ii) the BCB and NCN arrangements are nonpolar with zero dipole moment, (iii) the doping by a carbon line reduces the band gap regardless of the local arrangement of the borons and the nitrogens around the carbon line, and (iv) the polarization and energy gap of the carbon-doped BNNRs can be tuned by an electric field applied parallel to the carbon line. Similar effects were found when either an armchair or zigzag line of carbon was introduced. |
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Wos |
000311694200006 |
Publication Date |
2012-11-29 |
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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 |
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Impact Factor |
3.836 |
Times cited |
41 |
Open Access |
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Notes |
; We would like to thank J. M. Pereira and S. Goedecker for helpful discussions. This work was supported by the Flemish Science Foundation (FWO-Vl), the ESF-EuroGRAPHENE project CONGRAN. M. N.-A is supported by EU-Marie Curie IIF postdoc Fellowship/299522. ; |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
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Call Number |
UA @ lucian @ c:irua:105136 |
Serial |
1603 |
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Author |
Croitoru, M.D.; Vagov, A.; Shanenko, A.A.; Axt, V.M. |
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Title |
The Cooper problem in nanoscale : enhancement of the coupling due to confinement |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
Superconductor science and technology |
Abbreviated Journal |
Supercond Sci Tech |
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Volume |
25 |
Issue |
12 |
Pages |
124001-124005 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
In 1956 Cooper demonstrated (1956 Phys. Rev. 104 1189) that, no matter how weak the attraction is, two electrons in three-dimensional (3D) space just above the Fermi sea could be bound. In this work we investigate the influence of confinement on the binding energy of a Cooper pair. We show that confinement-induced modification of the Fermi sea results in a significant increase of the binding energy, when the bottom of an energy subband is very close to the Fermi surface. |
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Publisher |
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Place of Publication |
Bristol |
Editor |
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Wos |
000311418100004 |
Publication Date |
2012-11-08 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0953-2048;1361-6668; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.878 |
Times cited |
9 |
Open Access |
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Notes |
; MDC acknowledges support by the European Community under the Marie Curie IEF Action (Grant Agreement No. PIEF-GA-2009-235486-ScQSR). ; |
Approved |
Most recent IF: 2.878; 2012 IF: 2.758 |
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Call Number |
UA @ lucian @ c:irua:105121 |
Serial |
3573 |
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Author |
Bogaerts, A.; Aerts, R.; Snoeckx, R.; Somers, W.; Van Gaens, W.; Yusupov, M.; Neyts, E. |
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Title |
Modeling of plasma and plasma-surface interactions for medical, environmental and nano applications |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
Journal of physics : conference series |
Abbreviated Journal |
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Volume |
399 |
Issue |
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Pages |
012011 |
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Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
In this paper, an overview is given of modeling investigations carried out in our research group for a better understanding of plasmas used for medical, environmental and nano applications. The focus is both on modeling the plasma chemistry and the plasma-surface interactions. The plasma chemistry provides the densities and fluxes of the important plasma species. This information can be used as input when modeling the plasma-surface interactions. The combination of plasma simulations and plasma – surface interaction simulations provides a more comprehensive understanding of the underlying processes for these applications. |
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Place of Publication |
Bristol |
Editor |
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Wos |
000312261700011 |
Publication Date |
2012-11-26 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1742-6588;1742-6596; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
7 |
Open Access |
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Notes |
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Approved |
Most recent IF: NA |
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Call Number |
UA @ lucian @ c:irua:104727 |
Serial |
2130 |
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Author |
Smits, M.; Ling, Y.; Lenaerts, S.; Van Doorslaer, S. |
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Title |
Photocatalytic removal of soot : unravelling of the reaction mechanism by EPR and in situ FTIR spectroscopy |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
ChemPhysChem : a European journal of chemical physics and physical chemistry |
Abbreviated Journal |
Chemphyschem |
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Volume |
13 |
Issue |
18 |
Pages |
4251-4257 |
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Keywords |
A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
Photocatalytic soot oxidation is studied on P25 TiO2 as an important model reaction for self-cleaning processes by means of electron paramagnetic resonance (EPR) and Fourier transform infrared (FTIR) spectroscopy. Contacting of carbon black with P25 leads on the one hand to a reduction of the local dioxygen concentration in the powder. On the other hand, the weakly adsorbed radicals on the carbon particles are likely to act as alternative traps for the photogenerated conduction-band electrons. We find furthermore that the presence of dioxygen and oxygen-related radicals is vital for the photocatalytic soot degradation. The complete oxidation of soot to CO2 is evidenced by in situ FTIR spectroscopy, no intermediate CO is detected during the photocatalytic process. |
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Wos |
000313692600026 |
Publication Date |
2012-11-13 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1439-4235 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.075 |
Times cited |
9 |
Open Access |
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Notes |
; This work was supported by the University of Antwerp (PhD grants of M. S. and Y.L.). We would like to thank Birger Hauchecorne for the scientific discussion. ; |
Approved |
Most recent IF: 3.075; 2012 IF: 3.349 |
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Call Number |
UA @ admin @ c:irua:104568 |
Serial |
5980 |
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Author |
Krekels, T.; Zou, H.; Van Tendeloo, G.; Wagener, D.; Buchgeister, M.; Hosseini, S.M.; Herzog, P. |
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Title |
Ortho-II structure in ABa2Cu3O7-\delta compounds (A=Er, Nd, Pr, Sm, Yb) |
Type |
A1 Journal article |
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Year |
1992 |
Publication |
Physica: C : superconductivity |
Abbreviated Journal |
Physica C |
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Volume |
196 |
Issue |
3-4 |
Pages |
363-368 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Oxygen ordering has been investigated in superconducting ABa2Cu3O7-delta ceramic materials with A = Er, Nd, Sm and Yb, as well as in samples of this type with the rate earth A partially substituted by Pr. The critical temperature T(c) was determined as a function of the oxygen deficiency-delta of the compound and the corresponding microstructures were investigated by electron diffraction and electron microscopy. A distinct relationship exists between the width of the 60 K plateau and the ortho II ordering. Our results show that the ortho II ordered phase is the superconducting phase with a characteristic T(c) of 60 K. |
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Place of Publication |
Amsterdam |
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Wos |
A1992JC73400021 |
Publication Date |
2002-10-17 |
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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 |
0921-4534; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
0.942 |
Times cited |
52 |
Open Access |
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Notes |
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Approved |
PHYSICS, APPLIED 28/145 Q1 # |
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Call Number |
UA @ lucian @ c:irua:104547 |
Serial |
2531 |
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Author |
Vanhellemont, J.; Maes, H.E.; Schaekers, M.; Armigliato, A.; Cerva, H.; Cullis, A.; de Sande, J.; Dinges, H.; Hallais, J.; Nayar, V.; Pickering, C.; Stehlé, J.L.; Van Landuyt, J.; Walker, C.; Werner, H.; Salieri, P.; |
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Title |
Round-robin investigation of silicon-oxide on silicon reference materials for ellipsometry |
Type |
A1 Journal article |
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Year |
1993 |
Publication |
Applied surface science
T2 – SYMP ON DIAGNOSTIC TECHNIQUES FOR SEMICONDUCTOR MATERIALS ANALYSIS AND, FABRICATION PROCESS CONTROL, AT THE 1992 SPRING CONF OF THE EUROPEAN, MATERIALS RESEARCH SOC, JUN 02-05, 1992, STRASBOURG, FRANCE |
Abbreviated Journal |
Appl Surf Sci |
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Volume |
63 |
Issue |
1-4 |
Pages |
45-51 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The main results and conclusions are presented of a round robin study of silicon oxide on silicon reference samples for ellipsometry. The oxide films with nominal thicknesses of 10, 50 and 120 nm are grown by thermal oxidation. The oxide film thicknesses have been determined by single wavelength ellipsometry (SWE), by spectroscopic ellipsometry (SE) and by cross-sectional conventional and high-resolution transmission electron microscopy (TEM and HREM) in different laboratories. The main conclusions are that special precautions have to be taken in order to use TEM as a reliable thickness measurement technique; that single wavelength ellipsometry can be used with great accuracy and reproducibility for the 50 and 120 nm film thicknesses but that it shows some inherent problems for the 10 nm films; and that spectroscopic ellipsometry showed for all film thicknesses an accuracy and reproducibility which is clearly superior to that of SWE. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
Elsevier science bv |
Place of Publication |
Amsterdam |
Editor |
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| |
Language |
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Wos |
A1993KF03400009 |
Publication Date |
2002-10-16 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
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Edition |
|
|
| |
ISSN |
0169-4332; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
2.711 |
Times cited |
13 |
Open Access |
|
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| |
Notes |
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Approved |
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| |
Call Number |
UA @ lucian @ c:irua:104539 |
Serial |
2932 |
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| Permanent link to this record |
| |
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| |
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Author |
Martin, C.; Hervieu, M.; Huvé, M.; Michel, C.; Maignan, A.; Van Tendeloo, G.; Raveau, B. |
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| |
Title |
Lead-mercury-based superconductors – the 1212-cuprate Pb0.7Hg0.3Sr2+xCa0.7Nd0.3-xCu2O7-\delta and the new oxycarbonate Pb0.7Hg0.3Sr4Cu2CO3O7 |
Type |
A1 Journal article |
| |
Year |
1994 |
Publication |
Physica: C : superconductivity |
Abbreviated Journal |
Physica C |
|
| |
Volume |
222 |
Issue |
1-2 |
Pages |
19-26 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
A new superconducting mercury oxycarbonate, Pb0.7Hg0.3Sr4Cu2CO3O7, has been synthesized. This tetragonal phase (a = 3.824 angstrom, c= 16.468 angstrom) consists of an intergrowth of two nonsuperconducting compounds, Sr2CuO2CO3 and Pb0.7Hg0.3Sr2CuO5. It exhibits after optimization a critical temperature of 70 K, with a sharp transition and a superconducting volume fraction of 50%. Its behavior can be compared to that of thallium oxycarbonates previously isolated. This study is completed by a reinvestigation of the 1212 cuprate of the system Hg-Pb-Sr-Ca-Nd-Cu. A superconducting phase with the 1212 structure, similar to that previously obtained but with a significantly different composition, Pb0.7Hg0.3Sr2+xCa0.7Nd0.3-xCu2O7, has been obtained, with a T(c onset) of 100 K. The behavior of the latter is compared with other lead-based 1212 cuprates. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Amsterdam |
Editor |
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| |
Language |
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Wos |
A1994NB49400004 |
Publication Date |
2002-10-17 |
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| |
Series Editor |
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Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0921-4534; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
0.942 |
Times cited |
49 |
Open Access |
|
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| |
Notes |
|
Approved |
no |
|
| |
Call Number |
UA @ lucian @ c:irua:104517 |
Serial |
1813 |
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| Permanent link to this record |
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| |
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Author |
Huve, M.; Martin, C.; Maignan, A.; Michel, C.; Van Tendeloo, G.; Hervieu, M.; Raveau, B. |
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| |
Title |
A new cuprate with mercury bilayers : the “2222” oxide Hg2-xMxBa2Pr2Cu2O10-\delta (M= Cu,Pr) |
Type |
A1 Journal article |
| |
Year |
1995 |
Publication |
Journal of solid state chemistry |
Abbreviated Journal |
J Solid State Chem |
|
| |
Volume |
114 |
Issue |
1 |
Pages |
230-235 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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| |
Abstract |
A ''2222'' cuprate with mercury bilayers (Hg1.5Cu0.2Pr0.3)Ba2Pr2Cu2O10-delta, has been synthesized for the first time. It crystallizes in the P4/nmm space group with a = 3.9072(1) Angstrom and c = 17.219(1) Angstrom. The powder XRD and HREM studies of this new cuprate show that its structure consists of an intergrowth of double pyramidal (oxygen-deficient perovskite) copper layers, with double fluorite-type layers and distorted triple rock salt layers (mercury bilayers). The structure of this phase can be deduced from that of the ''2212'' mercury cuprate (Hg1.5Cu0.2Pr0.3)Ba2PrCu2O8-delta by the introduction of one additional [PrO2]infinity fluorite layer. The regular stacking of the metallic layer and the uniform cationic distribution in the mercury bilayers are remarkable features of this cuprate. The stabilization of the mercury bilayers by praseodymium and the absence of superconductivity are discussed. (C) 1995 Academic Press, Inc. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
London |
Editor |
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| |
Language |
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Wos |
A1995QA17000033 |
Publication Date |
2002-10-07 |
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| |
Series Editor |
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Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0022-4596; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
2.133 |
Times cited |
6 |
Open Access |
|
|
| |
Notes |
|
Approved |
PHYSICS, APPLIED 28/145 Q1 # |
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| |
Call Number |
UA @ lucian @ c:irua:104448 |
Serial |
2310 |
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| Permanent link to this record |
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| |
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Author |
Radaelli, P.G.; Marezio, M.; Tholence, J.L.; Debrion, S.; Santoro, A.; Huang, Q.; Capponi, J.J.; Chaillout, C.; Krekels, T.; Van Tendeloo, G. |
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| |
Title |
Crystal-structure of the double-hg-layer copper-oxide superconductor (Hg,Pr)2Ba2(Y,Ca)Cu2O8-\deltaas a function of doping |
Type |
A1 Journal article |
| |
Year |
1995 |
Publication |
The journal of physics and chemistry of solids |
Abbreviated Journal |
J Phys Chem Solids |
|
| |
Volume |
56 |
Issue |
10 |
Pages |
1471-1478 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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| |
Abstract |
The crystal structure of the newly discovered double-Hg-layer copper oxide superconductor (Hg, Pr)(2)Ba-2(Y, Ca)Cu2O8-delta was studied as a function of chemical doping using neutron and electron diffraction and high-resolution transmission electron microscopy (HREM). Rietveld refinements of the structural parameters from neutron powder diffraction data indicate that the oxygen site O3 on the mercury plane is highly defective, being both partially occupied and displaced from the high-symmetry position. The variable concentration of oxygen vacancies partially compensates for the cation doping and, together with the O3 displacement field, makes some of the Hg atoms acquire an unusual pyramidal coordination. HREM images confirm that the structure is of the '2212' type, with very few defects. In some grains, faint superstructure reflections were evidenced by electron diffraction, suggesting that both the oxygen vacancies and the O3 displacement field may order at least on a local scale. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
New York, N.Y. |
Editor |
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| |
Language |
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Wos |
A1995RR95600025 |
Publication Date |
2002-07-26 |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
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| |
ISSN |
0022-3697; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
1.853 |
Times cited |
16 |
Open Access |
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| |
Notes |
|
Approved |
no |
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| |
Call Number |
UA @ lucian @ c:irua:104423 |
Serial |
574 |
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| Permanent link to this record |
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Author |
Shi, J.M.; Koenraad, P.M.; van de Stadt, A.F.W.; Peeters, F.M.; Devreese, J.T.; Wolter, J.H. |
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| |
Title |
Electronic structure of a Si \delta-doped layer in a GaAs/AlxGa1-xAs/GaAs quantum barrier |
Type |
A1 Journal article |
| |
Year |
1996 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
|
| |
Volume |
54 |
Issue |
11 |
Pages |
7996-8004 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems |
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| |
Abstract |
We present a theoretical study of the electronic structure of a heavily Si delta-doped layer in a GaAs/AlxGa1-xAs/GaAs quantum barrier. In this class of structures the effect of DX centers on the electronic properties can be tuned by changing the AlxGa1-xAs barrier width and/or the Al concentration, which leads to a lowering of the DX level with respect to the Fermi energy without disturbing the wave functions much. A self-consistent approach is developed in which the effective confinement potential and the Fermi energy of the system, the energies, the wave functions, and the electron densities of the discrete subbands have been obtained as a function of both the material parameters of the samples and the experimental conditions. The effect of DX centers on such structures at nonzero temperature and under an external pressure is investigated for three different models: (1) the DX(nc)(0) model with no correlation effects, (2) the d(+)/DX(0) model, and (3) the d(+)/DX(-) model with inclusion of correlation effects. In the actual calculation, influences of the background accepters, the discontinuity of the effective mass of the electrons at the interfaces of the different materials, band nonparabolicity, and the exchange-correlation energy of the electrons have been taken into account. We have found that (1) introducing a quantum barrier into delta-doped GaAs makes it possible to control the energy gaps between different electronic; subbands; (2) the electron wave functions are mon spread out when the repellent effect of the barriers is increased as compared to those in delta-doped GaAs; (3) increasing the quantum-barrier height and/or the application of hydrostatic pressure are helpful to experimentally observe the effect of the DX centers through a decrease of the total free-electron density; and (4) the correlation effects of the charged impurities are important for the systems under study. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Lancaster, Pa |
Editor |
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| |
Language |
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Wos |
A1996VL14500066 |
Publication Date |
2002-07-27 |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
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| |
ISSN |
0163-1829;1095-3795; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.736 |
Times cited |
11 |
Open Access |
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| |
Notes |
|
Approved |
no |
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| |
Call Number |
UA @ lucian @ c:irua:104388 |
Serial |
1012 |
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| Permanent link to this record |
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| |
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Author |
Maignan, A.; Martin, C.; Van Tendeloo, G.; Hervieu, M.; Raveau, B. |
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| |
Title |
Size mismatch : a crucial factor for generating a spin-glass insulator in manganites |
Type |
A1 Journal article |
| |
Year |
1999 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
60 |
Issue |
22 |
Pages |
15214-15219 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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| |
Abstract |
Thr structural, electronic, and magnetic properties of the highly mismatched perovskite oxides, Th(0.35)A(0.65)MnO(3), where Ais for the alkaline earth divalent cations (Ca, Ba, Sr), which are all characterized by the same large tolerance factor (t=0.934), have been investigated by using electron microscopy, electrical resistivity, magnetic susceptibility, and magnetization. It is clearly established that a transition from ferromagnetic metallic towards spin-glass insulator samples is induced as the A-site cationic size mismatch is increased. Moreover, the magnetoresistance (MR) properties of these manganites are strongly reduced for the spin-glass insulators, demonstrating that the A-sire cationic disorder is detrimental for the colossal MR properties. Based on these results, a new electronic and magnetic diagram is established that shows that the A-site disorder, rather than the A-site average cationic size (or t) is the relevant factor for generating spin-glass insulating manganites. [S0163-1829(99)01746-4]. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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| |
Language |
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Wos |
000084631600039 |
Publication Date |
2002-07-27 |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
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| |
ISSN |
0163-1829;1095-3795; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.836 |
Times cited |
75 |
Open Access |
|
|
| |
Notes |
|
Approved |
Most recent IF: 3.836; 1999 IF: NA |
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| |
Call Number |
UA @ lucian @ c:irua:104280 |
Serial |
3038 |
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| Permanent link to this record |
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| |
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Author |
Schuddinck, W.; Van Tendeloo, G.; Barnabé, A.; Hervieu, M.; Raveau, B. |
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| |
Title |
Relation between structure, charge ordering and magnetotransport properties in Nd0.5Ca0.5Mn1-xCrxO3 manganites |
Type |
A1 Journal article |
| |
Year |
2000 |
Publication |
Journal of magnetism and magnetic materials
T2 – Symposium G Material Physics Issues and Applications of Magnetic Oxides, at the E-MRS Spring Meeting, JUN 01-04, 1999, Strasbourg, France |
Abbreviated Journal |
J Magn Magn Mater |
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| |
Volume |
211 |
Issue |
1-3 |
Pages |
105-110 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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| |
Abstract |
The relationships between incommensurability, charge ordering and magnetotransport properties in Nd0.5Ca0.5Mn1-xCrxO3 manganites have been studied by electron diffraction and lattice imaging versus temperature with 0.02 less than or equal to x less than or equal to 0.07. All compositions show an incommensurate superstructure over the whole temperature domain, despite the fact that they are ferromagnetic and conductive below 140 K, The q-vector (1/2 – delta)a* decreases with increasing temperature for all compositions x. For a given temperature q also decreases with x. Lattice images obtained at low temperature give a clear view of the characteristics of the incommensurate structure. They also provide a better understanding of the charge ordering process. The low-temperature form of the Cr-doped manganites is not a perfectly doubled cell [[2a(p)root 2 x 2a(p) x a(p)root 2]], but defects inducing a tripled cell occur pseudo-periodically. (C) 2000 Elsevier Science B.V. All rights reserved. |
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Address |
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Corporate Author |
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Thesis |
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| |
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
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| |
Language |
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Wos |
000085772100017 |
Publication Date |
2002-07-25 |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
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| |
ISSN |
0304-8853; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
2.63 |
Times cited |
16 |
Open Access |
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| |
Notes |
|
Approved |
Most recent IF: 2.63; 2000 IF: 0.996 |
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| |
Call Number |
UA @ lucian @ c:irua:104256 |
Serial |
2858 |
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| Permanent link to this record |
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| |
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Author |
Lei, C.H.; Van Tendeloo, G.; Siegert, M.; Schubert, J.; Buchal, C. |
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| |
Title |
Structural investigation of the epitaxial yittria-stabilized zirconia films deposited on (001) silicon by laser ablation |
Type |
A1 Journal article |
| |
Year |
2001 |
Publication |
Journal of crystal growth |
Abbreviated Journal |
J Cryst Growth |
|
| |
Volume |
222 |
Issue |
3 |
Pages |
558-564 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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| |
Abstract |
Yittria-stabilized zirconia (YSZ) films doped with 3 and 9 vol%. Y(2)O(3), respectively, are epitaxially deposited on (0 0 1) silicon substrates by means of pulsed laser deposition (PLD) technique. Transmission electron microscopy (TEM) and X-ray diffraction are mainly combined to study the film microstructure. It is: found that the film structure strongly depends on the amount of Y(2)O(3) dopant. 99/0 Y(2)O(3)-doped films display a near cubic structure; 45 degrees 1/2(1 1 0) dislocations are the main defects in the film and thermal cracks are formed during cooling. The 3% Y(2)O(3)-doped films are dominated by {1 1 0} twin-related tetragonal domains in which monoclinic phase is found. The films are free of thermal cracks even for films thicker than 2 mum. (C) 2001 Elsevier Science B.V. All rights reserved. |
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Address |
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Corporate Author |
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Thesis |
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| |
Publisher |
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Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
000166701500020 |
Publication Date |
2002-07-25 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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| |
Series Volume |
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Series Issue |
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Edition |
|
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| |
ISSN |
0022-0248; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
1.751 |
Times cited |
12 |
Open Access |
|
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| |
Notes |
|
Approved |
Most recent IF: 1.751; 2001 IF: 1.283 |
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| |
Call Number |
UA @ lucian @ c:irua:104211 |
Serial |
3240 |
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| Permanent link to this record |
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| |
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Author |
Tokei, Z.; Lanckmans, F.; van den Bosch, G.; Van Hove, M.; Maex, K.; Bender, H.; Hens, S.; van Landuyt, J. |
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| |
Title |
Reliability of copper dual damascene influenced by pre-clean |
Type |
P1 Proceeding |
| |
Year |
2002 |
Publication |
Analysis Of Integrated Circuits |
Abbreviated Journal |
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| |
Volume |
|
Issue |
|
Pages |
118-123 |
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| |
Keywords |
P1 Proceeding; Electron microscopy for materials research (EMAT) |
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Abstract |
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Address |
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Corporate Author |
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Thesis |
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| |
Publisher |
Ieee |
Place of Publication |
New york |
Editor |
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| |
Language |
|
Wos |
000177689400022 |
Publication Date |
2003-06-25 |
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| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
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| |
ISSN |
|
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
|
Times cited |
5 |
Open Access |
|
|
| |
Notes |
Conference name: |
Approved |
Most recent IF: NA |
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| |
Call Number |
UA @ lucian @ c:irua:104170 |
Serial |
2865 |
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| Permanent link to this record |
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| |
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Author |
Anisimovas, E.; Peeters, F.M. |
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| |
Title |
Correlated few-particle states in artificial bipolar molecule |
Type |
A1 Journal article |
| |
Year |
2002 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
65 |
Issue |
23 |
Pages |
233302-233304 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
We investigate the ground and excited states of a bipolar artificial molecule composed of two vertically coupled quantum dots containing different type of carriers-electrons and holes-in equilibrium. The approach based on exact diagonalization is used and reveals an intricate pattern of ground-state angular momentum switching and a rearrangement of approximate single-particle levels as a function of the interdot coupling strength. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000176767900019 |
Publication Date |
2002-07-27 |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
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| |
ISSN |
0163-1829;1095-3795; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.836 |
Times cited |
14 |
Open Access |
|
|
| |
Notes |
|
Approved |
Most recent IF: 3.836; 2002 IF: NA |
|
| |
Call Number |
UA @ lucian @ c:irua:104154 |
Serial |
519 |
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| Permanent link to this record |
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| |
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Author |
Fleurov, V.; Ivanov, V.A.; Peeters, F.M.; Vagner, I.D. |
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| |
Title |
Spin-engineered quantum dots |
Type |
A1 Journal article |
| |
Year |
2002 |
Publication |
Physica. E: Low-dimensional systems and nanostructures |
Abbreviated Journal |
Physica E |
|
| |
Volume |
14 |
Issue |
4 |
Pages |
361-365 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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| |
Abstract |
Spatially nonhomogeneously spin polarized nuclei are proposed as a new mechanism to monitor electron states in a nanostructure, or as a means to create and, if necessary, reshape such nanostructures in the course of the experiment. We found that a polarization of nuclear spins may lift the spin polarization of the electron states in a nanostructure and, if sufficiently strong, leads to a polarization of the electron spins. Polarized nuclear spins may form an energy landscape capable of binding electrons with energy up to several meV and the localization radius > 100 Angstrom. (C) 2002 Elsevier Science B.V. All rights reserved. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
North-Holland |
Place of Publication |
Amsterdam |
Editor |
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| |
Language |
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Wos |
000177511900003 |
Publication Date |
2002-10-15 |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
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Edition |
|
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| |
ISSN |
1386-9477; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
2.221 |
Times cited |
12 |
Open Access |
|
|
| |
Notes |
|
Approved |
Most recent IF: 2.221; 2002 IF: 1.107 |
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| |
Call Number |
UA @ lucian @ c:irua:104150 |
Serial |
3088 |
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| Permanent link to this record |
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| |
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Author |
Vodolazov, D.Y.; Baelus, B.J.; Peeters, F.M. |
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| |
Title |
Stationary-phase slip state in quasi-one-dimensional rings |
Type |
A1 Journal article |
| |
Year |
2002 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
|
| |
Volume |
66 |
Issue |
5 |
Pages |
054531-54536 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
The nonuniform superconducting state in a ring in which the order parameter vanishing at one point is studied. This state is characterized by a jump of the phase by pi at the point where the order parameter becomes zero. In uniform rings such a state is a saddle-point state and consequently unstable. However, for nonuniform rings with, e.g., variations of geometrical or physical parameters or with attached wires this state can be stabilized and may be realized experimentally. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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| |
Language |
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Wos |
000177873000137 |
Publication Date |
2002-10-01 |
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| |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
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| |
ISSN |
0163-1829;1095-3795; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.836 |
Times cited |
29 |
Open Access |
|
|
| |
Notes |
|
Approved |
Most recent IF: 3.836; 2002 IF: NA |
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| |
Call Number |
UA @ lucian @ c:irua:104147 |
Serial |
3152 |
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| Permanent link to this record |
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| |
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Author |
Peeters, F.M.; Vasilopoulos, P.; Shi, J. |
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| |
Title |
Density of states and Fermi level of a periodically modulated two-dimensional electron gas |
Type |
A1 Journal article |
| |
Year |
2002 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
|
| |
Volume |
14 |
Issue |
38 |
Pages |
8803-8816 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
Explicit analytic expressions are obtained for the density of states D(E) and Fermi energy E-F of a two-dimensional electron gas in the presence of a weak and periodic unidirectional electric or magnetic modulation and of a uniform perpendicular magnetic field B. The Landau levels broaden into bands and their width, proportional to the modulation strength, oscillates with B and gives rise to Weiss oscillations in D(E), E-F and the transport coefficients. When both electric and magnetic modulations are present the position of the resulting oscillations depends on the ratio delta between the two modulation strengths. When the modulations are out of phase there is no shift in the position of the oscillations when delta varies and for a particular value of delta the oscillations are suppressed. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
London |
Editor |
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| |
Language |
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Wos |
000178678400008 |
Publication Date |
2002-09-18 |
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| |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
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| |
ISSN |
0953-8984; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
2.649 |
Times cited |
8 |
Open Access |
|
|
| |
Notes |
|
Approved |
Most recent IF: 2.649; 2002 IF: 1.775 |
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| |
Call Number |
UA @ lucian @ c:irua:104140 |
Serial |
640 |
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| Permanent link to this record |
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Author |
Bogaerts, A.; Grozeva, M. |
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| |
Title |
Effect of helium/argon gas ratio in a He-Ar-Cu+ IR hollow-cathode discharge laser : modeling study and comparison with experiments |
Type |
A1 Journal article |
| |
Year |
2003 |
Publication |
Applied physics B : lasers and optics |
Abbreviated Journal |
Appl Phys B-Lasers O |
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| |
Volume |
76 |
Issue |
3 |
Pages |
299-306 |
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| |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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| |
Abstract |
The He-Ar-Cu+ IR laser operates in a hollow-cathode discharge, typically in a mixture of helium with a few-% Ar. The population inversion of the Cu+ ion levels, responsible for laser action, is attributed to asymmetric charge transfer between He+ ions and sputtered Cu atoms. The Ar gas is added to promote sputtering of the Cu cathode. In this paper, a hybrid modeling network consisting of several different models for the various plasma species present in a He-Ar-Cu hollow-cathode discharge is applied to investigate the effect of Ar concentration in the gas mixture on the discharge behavior, and to find the optimum He/Ar gas ratio for laser operation. It is found that the densities of electrons, Ar+ ions, Ar-m* metastable atoms, sputtered Cu atoms and Cu+ ions increase upon the addition of more Ar gas, whereas the densities of He+ ions, He-2(+) ions and He-m* metastable atoms drop considerably. The product of the calculated Cu atom and He+ ion densities, which determines the production rate of the upper laser levels, and hence probably also the laser output power, is found to reach a maximum around 1-5% Ar addition. This calculation result is compared to experimental measurements, and reasonable agreement has been reached. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Berlin |
Editor |
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| |
Language |
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Wos |
000182758000017 |
Publication Date |
2004-03-19 |
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| |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
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| |
ISSN |
0946-2171;1432-0649; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
1.696 |
Times cited |
6 |
Open Access |
|
|
| |
Notes |
|
Approved |
Most recent IF: 1.696; 2003 IF: 2.012 |
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| |
Call Number |
UA @ lucian @ c:irua:104125 |
Serial |
812 |
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| Permanent link to this record |
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| |
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Author |
Ferreira, W.P.; Matulis, A.; Farias, G.A.; Peeters, F.M. |
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| |
Title |
Structure and correlations in two-dimensional classical artificial atoms confined by a Coulomb potential |
Type |
A1 Journal article |
| |
Year |
2003 |
Publication |
Physical review : E : statistical, nonlinear, and soft matter physics |
Abbreviated Journal |
Phys Rev E |
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| |
Volume |
67 |
Issue |
4Part 2 |
Pages |
046601-46608 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
The ordering of N equally charged particles (-e) moving in two dimensions and confined by a Coulomb potential, resulting from a displaced positive charge Ze is discussed. This is a classical model system for atoms. We obtain the configurations of charged particles which, depending on the value of N and Z, may result in ring structures, hexagonal-type configurations, and for N/Z approximate to 1 in an inner structure of particles which is separated by an outer ring of particles. For N/Z << 1, the Hamiltonian of the parabolic confinement case is recovered. For N/Z approximate to 1, the configurations are very different from those found in the case of a parabolic confinement potential. A hydrodynamic analysis is presented in order to highlight the correlations effects. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
American Institute of Physics |
Place of Publication |
Woodbury (NY) |
Editor |
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| |
Language |
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Wos |
000182825400087 |
Publication Date |
2003-04-03 |
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| |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
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| |
ISSN |
1063-651X;1095-3787; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
2.366 |
Times cited |
14 |
Open Access |
|
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| |
Notes |
|
Approved |
Most recent IF: 2.366; 2003 IF: 2.202 |
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| |
Call Number |
UA @ lucian @ c:irua:104123 |
Serial |
3273 |
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| Permanent link to this record |
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Author |
Vasilopoulos, P.; Wang, X.F.; Peeters, F.M.; Chowdhury, S.; Long, A.R.; Davies, J.H. |
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| |
Title |
Magneto resistance oscillations in a modulated 2DEG periodic in the ratio h/e to flux per unit cell |
Type |
A1 Journal article |
| |
Year |
2004 |
Publication |
Physica. E: Low-dimensional systems and nanostructures
T2 – 15th International Conference on Electronic Properties of, Two-Dimensional Systems (EP2DS-15), JUL 14-18, 2003, Nara, JAPAN |
Abbreviated Journal |
Physica E |
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| |
Volume |
22 |
Issue |
1-3 |
Pages |
389-393 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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| |
Abstract |
Transport properties of the 2DEG are studied in the presence of a normal magnetic field B and of a weak, two-dimensional periodic potential modulation. A tight-binding treatment has shown that each Landau level splits into several subbands with exponentially small gaps between them. Assuming the latter are closed due to disorder gives analytical wave functions and simplifies the evaluation of the magnetoresistance tensor p(muv) The relative phase of the oscillations in p(xx) and p(yy) depends on the modulation strengths and periods. For short periods less than or equal to 100 nm, in addition to the Weiss oscillations, the collisional contribution to the conductivity and the corresponding resistivity contribution show prominent peaks when one flux quantum h/e passes through an integral number of unit cells in good agreement with experiments. For periods 300-400 nm long used in early experiments, these peaks occur at fields 10-25 times smaller than those of the Weiss oscillations and are not resolved. (C) 2003 Elsevier B.V. All rights reserved. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
North-Holland |
Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
000221140800094 |
Publication Date |
2004-02-10 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1386-9477; |
ISBN |
|
Additional Links |
UA library record; WoS full record |
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| |
Impact Factor |
2.221 |
Times cited |
|
Open Access |
|
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| |
Notes |
|
Approved |
Most recent IF: 2.221; 2004 IF: 0.898 |
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| |
Call Number |
UA @ lucian @ c:irua:104107 |
Serial |
1911 |
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| Permanent link to this record |
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Author |
Krstajic, P.; Peeters, F.M. |
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Title |
Spin-dependent tunneling in diluted magnetic semiconductor trilayer structures |
Type |
A1 Journal article |
| |
Year |
2005 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
72 |
Issue |
12 |
Pages |
125350-125356 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Tunneling of holes through a trilayer structure made of two diluted magnetic semiconductors, (Ga,Mn)As, separated by a thin layer of nonmagnetic AlAs is investigated. The problem is treated within the 6x6 Luttinger-Kohn model for valence bands with the split-off band included. The influence of the spin-orbit coupling is pronounced as the spin-splitting Delta(ex) is comparable with the split-off Delta(SO) splitting. It is assumed that direct tunneling is the dominant mechanism due to the high quality of the tunnel junctions. Our theoretical results predict the correct order of magnitude for the tunneling magnetoresistance ratio, but various other effects, such as scattering on impurities and defects, should be included in order to realize a quantitative agreement with experiment. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000232229400116 |
Publication Date |
2005-09-30 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1098-0121;1550-235X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.836 |
Times cited |
8 |
Open Access |
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| |
Notes |
|
Approved |
Most recent IF: 3.836; 2005 IF: 3.185 |
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| |
Call Number |
UA @ lucian @ c:irua:104068 |
Serial |
3086 |
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| Permanent link to this record |
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| |
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Author |
Ferreira, W.P.; Peeters, F.M.; Farias, G.A. |
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Title |
Melting and evaporation in classical two-dimensional clusters confined by a Coulomb potential |
Type |
A1 Journal article |
| |
Year |
2005 |
Publication |
Physical review : E : statistical, nonlinear, and soft matter physics |
Abbreviated Journal |
Phys Rev E |
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| |
Volume |
72 |
Issue |
4 Part 1 |
Pages |
041502-41507 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The thermal properties of a two-dimensional classical cluster of negatively charged particles bound by a punctual positive charge are presented. The melting phenomenon is analyzed and the features which characterize such a solid-liquid transition are highlighted. We found that the presence of metastable states strongly modifies the melting scenario, and that the melting temperature of the system is determined by the height of the saddle point energy separating the ground state and the metastable state. Due to the particular type of confinement potential considered in this paper, we also found that, at sufficiently large temperature, the cluster can become thermally ionized. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
American Institute of Physics |
Place of Publication |
Woodbury (NY) |
Editor |
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Language |
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Wos |
000232930600030 |
Publication Date |
2005-10-06 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
1539-3755;1550-2376; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
2.366 |
Times cited |
4 |
Open Access |
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| |
Notes |
|
Approved |
Most recent IF: 2.366; 2005 IF: 2.418 |
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| |
Call Number |
UA @ lucian @ c:irua:104067 |
Serial |
1983 |
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| Permanent link to this record |
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Author |
Krsmanovic, R.; Morozov, V.A.; Lebedev, O.I.; Polizzi, S.; Speghini, A.; Bettinelli, M.; Van Tendeloo, G. |
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Title |
Structural and luminescence investigation on gadolinium gallium garnet nanocrystalline powders prepared by solution combustion synthesis |
Type |
A1 Journal article |
| |
Year |
2007 |
Publication |
Nanotechnology |
Abbreviated Journal |
Nanotechnology |
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| |
Volume |
18 |
Issue |
32 |
Pages |
325604-325609 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
Nanocrystalline powders of undoped and lanthanide (Pr3+, Tm3+)- doped gadolinium gallium garnet, Gd3Ga5O12 (GGG), were prepared by propellant synthesis and studied by x-ray powder diffraction (XRD), electron diffraction (ED), high-resolution electron microscopy (HREM) and luminescence spectroscopy. The x-ray diffraction patterns of the GGG samples were analysed using the Rietveld method. The Rietveld refinement reveals the existence of two garnet-type phases: both are cubic (space group Ia $(3) over bar $d) with a slightly different lattice parameter and probably a slightly different composition. Electron diffraction and electron microscopy measurements confirm the x-ray diffraction results. EDX measurements for lanthanide-doped samples show that stable solid solutions with composition Gd(3-x)Ln(x)Ga(5)O(12), x approximate to 0.3 ( Ln = Pr; Tm) have been obtained. The luminescence properties of the Tm3+ -doped nanocrystalline GGG samples were measured and analysed. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Bristol |
Editor |
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Language |
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Wos |
000248231300010 |
Publication Date |
2007-07-14 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
0957-4484;1361-6528; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.44 |
Times cited |
33 |
Open Access |
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| |
Notes |
Iap5-01 |
Approved |
Most recent IF: 3.44; 2007 IF: 3.310 |
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| |
Call Number |
UA @ lucian @ c:irua:104042 |
Serial |
3195 |
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| Permanent link to this record |
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| |
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Author |
Dzhurakhalov, A.A.; Atanasov, I.; Hou, M. |
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| |
Title |
Calculation of binary and ternary metallic immiscible clusters with icosahedral structures |
Type |
A1 Journal article |
| |
Year |
2008 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
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Issue |
|
Pages |
115415 |
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Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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| |
Abstract |
Recently, core-shell Ag-Co, Ag-Cu, and “onionlike” Cu-Co equilibrium configurations were predicted in the case of isolated face centered cubic (fcc) bimetallic clusters, and three shell onionlike configurations were predicted in the case of ternary metallic clusters with spherical and truncated octahedral morphologies. In the present paper, immiscible binary CuCo and ternary AgCuCo clusters with icosahedral structures are studied as functions of their size and composition. Clusters studied are formed by 13, 55, 147, 309, and 561 atoms corresponding to the five smallest possible closed shell icosahedral structures. An embedded atom model potential is used to describe their cohesion. Equilibrium configurations are investigated by means of Metropolis Monte Carlo free energy minimization in the (NPT) canonical ensemble. Most simulations are achieved at 10 and 300 K. The effect of temperature on segregation ordering is systematically investigated. Selected cases are used to identify the effect of size and composition on melting. In contrast with fcc clusters, homogeneous onionlike configurations of binary clusters are not predicted. When it is allowed by the composition, a complete outer shell is formed by Cu in binary Cu-Co clusters and by Ag in ternary Ag-Cu-Co clusters. Depending on temperature, Co may precipitate into decahedral groups under the Cu vertices of the icosahedra in binary clusters, while the Co-Cu configuration in ternary clusters drastically depends on the Ag coating. Despite the multicomponent character of the clusters and the immiscibility of the species forming them, for most compositions and sizes, equilibrium structures remain close to perfectly icosahedral at 10 K as well as at 300 K. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Lancaster, Pa |
Editor |
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Language |
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Wos |
000254542800167 |
Publication Date |
2008-03-11 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
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 |
11 |
Open Access |
|
|
| |
Notes |
|
Approved |
Most recent IF: 3.836; 2008 IF: 3.322 |
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| |
Call Number |
UA @ lucian @ c:irua:104033 |
Serial |
4517 |
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| Permanent link to this record |
