| Records |
| Author |
de Gryse, O.; Clauws, P.; Lebedev, O.; van Landuyt, J.; Vanhellemont, J.; Claeys, C.; Simoen, E. |
| Title |
Chemical and structural characterization of oxygen precipitates in silicon by infrared spectroscopy and TEM |
Type |
A1 Journal article |
| Year |
2001 |
Publication |
Physica: B : condensed matter
T2 – 21st International Conference on Defects in Semiconductors, JUL 16-20, 2001, GIESSEN, GERMANY |
Abbreviated Journal |
Physica B |
| Volume |
308 |
Issue |
|
Pages |
294-297 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Infrared absorption spectra of polyhedral and platelet oxygen precipitates are analyzed using a modified Day-Thorpe approach (J. Phys.: Condens. Matter 11 (1999) 2551). The aspect ratio has been determined by TEM measurements. The reduced spectral function and the stoichiometry are extracted from the absorption spectra and the concentration of precipitated interstitial oxygen. One set of spectra reveal a Frohlich frequency around 1100 cm(-1) and another around 1110-1120 cm(-1). It is shown that the shift in the Frohlich frequency is not due to a different stoichiometry, but due to the detailed structure in the reduced spectral function. The oxygen precipitates consist of SiO. with gammaapproximate to1.1-1.2+/-0.1. (C) 2001 Elsevier Science B.V. All rights reserved. |
| 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 |
|
| Language |
|
Wos |
000173660100073 |
Publication Date |
2002-10-15 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0921-4526; |
ISBN |
|
Additional Links  |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.386 |
Times cited |
3 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 1.386; 2001 IF: 0.663 |
| Call Number |
UA @ lucian @ c:irua:103389 |
Serial |
345 |
| Permanent link to this record |
| |
|
| |
| Author |
Mishra, R.S.K.; Pandey, D.; Lemmens, H.; Van Tendeloo, G. |
| Title |
Evidence for another low-temperature phase transition in tetragonal Pb(ZrxTi1-x)O3 (x=0.515,0.520) |
Type |
A1 Journal article |
| Year |
2001 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
64 |
Issue |
5 |
Pages |
054104 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Results of dielectric and resonance frequency (f(r)) measurements below room temperature are presented for Pb(ZrxTi1-x)O-3, x = 0.515 and 0.520. It is shown that the temperature coefficient of f(r) changes sign from negative to positive around 210 and 265 K for x = 0.520 and 200 and 260 K for x = 0.515. Anomalies in the real part of the dielectric constant (epsilon') are observed around the same temperatures at which the temperature coefficient of f(r) changes sign because of the electrostrictive coupling between the elastic and dielectric responses. Low-temperature powder x-ray-diffraction (XRD) data, however, reveal only one transition from the tetragonal to monoclinic phase similar to that reported by Noheda et al. [Phys. Rev. B, 61, 8687 (2000)]. Electron-diffraction data, on the other hand, reveal yet another structural transition at lower temperatures corresponding to the second anomaly in the epsilon' vs T and f(r) vs T curves. This second transition is shown to be a cell-doubling transition not observed by Noheda et al. in their XRD studies. The observation of superlattice reflections raises doubts about the correctness of the Cm space group proposed by Noheda et al. for the monoclinic phase of Pb(ZrxTi(1-x))O-3 below the second transition temperature. |
| 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 |
000170267000028 |
Publication Date |
2002-07-27 |
| Series Editor |
|
Series Title |
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Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0163-1829;1095-3795; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.836; 2001 IF: NA |
| Call Number |
UA @ lucian @ c:irua:103407 |
Serial |
1093 |
| Permanent link to this record |
| |
|
| |
| Author |
Peeters, F.M.; Riva, C.; Varga, K. |
| Title |
Trions in quantum wells |
Type |
A1 Journal article |
| Year |
2001 |
Publication |
Physica: B : condensed matter |
Abbreviated Journal |
Physica B |
| Volume |
300 |
Issue |
1-4 |
Pages |
139-155 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
An overview is given of our investigation of the energy levels and of the correlation functions of the negatively and positively charged excitons (also called trions) in quantum wells in the presence of a perpendicular magnetic field, A detailed comparison is made with available experimental data in III-V and II-VI semiconductor quantum wells. (C) 2001 Elsevier Science B.V. All rights reserved. |
| 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 |
|
| Language |
|
Wos |
000170850000011 |
Publication Date |
2002-07-25 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0921-4526; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.386 |
Times cited |
31 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 1.386; 2001 IF: 0.663 |
| Call Number |
UA @ lucian @ c:irua:103410 |
Serial |
3734 |
| Permanent link to this record |
| |
|
| |
| Author |
Fedina, L.; Lebedev, O.I.; Van Tendeloo, G.; van Landuyt, J.; Mironov, O.A.; Parker, E.H.C. |
| Title |
In situ HREM irradiation study of point-defect clustering in MBE-grown strained Si1-xGex/(001)Si structures |
Type |
A1 Journal article |
| Year |
2000 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
61 |
Issue |
15 |
Pages |
10336-10345 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
We present a detailed analysis of the point-defect clustering in strained Si/Si(1-x)Ge(x)/(001)Si structures, including the interaction of the point defects with the strained interfaces and the sample surface during 400 kV electron irradiation at room temperature. Point-defect cluster formation is very sensitive to the type and magnitude of the strain in the Si and Si(1-x)Ge(x) layers. A small compressive strain (-0.3%) in the SiGe alloy causes an aggregation of vacancies in the form of metastable [110]-oriented chains. They are located on {113} planes and further recombine with interstitials. Tensile strain in the Si layer causes an aggregation of interstitial atoms in the forms of additional [110] rows which are inserted on {113} planes with [001]-split configurations. The chainlike configurations are characterized by a large outward lattice relaxation for interstitial rows (0.13 +/-0.01 nm) and a very small inward relaxation for vacancy chains (0.02+/-0.01 nm). A compressive strain higher than -0.5% strongly decreases point-defect generation inside the strained SiGe alloy due to the large positive value of the formation volume of a Frenkel pair. This leads to the suppression of point-defect clustering in a strained SiGe alloy so that SiGe relaxes via a diffusion of vacancies from the Si layer, giving rise to an intermixing at the Si/SiGe interface. In material with a 0.9% misfit a strongly increased flow of vacancies from the Si layer to the SiGe layer and an increased biaxial strain in SiGe bath promote the preferential aggregation of vacancies in the (001) plane, which relaxes to form intrinsic 60 degrees dislocation loops. |
| 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 |
000086606200082 |
Publication Date |
2002-07-27 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0163-1829;1095-3795; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
27 |
Open Access |
|
| Notes |
Conference Name: Microsc. Semicond. Mater. Conf. |
Approved |
Most recent IF: 3.836; 2000 IF: NA |
| Call Number |
UA @ lucian @ c:irua:103456 |
Serial |
1577 |
| Permanent link to this record |
| |
|
| |
| Author |
Chwiej, T.; Bednarek, S.; Adamowski, J.; Szafran, B.; Peeters, F.M. |
| Title |
Coulomb-interaction driven anomaly in the Stark effect for an exciton in vertically coupled quantum dots |
Type |
A1 Journal article |
| Year |
2005 |
Publication |
Journal of luminescence
T2 – 6th International Conference on Excitonic Processes in Condensed Matter, (EXCON 04), JUL 06-09, 2004, Cracow, POLAND |
Abbreviated Journal |
J Lumin |
| Volume |
112 |
Issue |
1-4 |
Pages |
122-126 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The effect of the electric field on an exciton confined in a pair of vertically coupled quantum dots is studied. We use a single-band approximation and a parabolic model potential. As a result of these idealizations, we obtain a numerically solvable model, which is used to describe the influence of the electron-hole interaction on the Stark effect for the lowest-energy photo luminescence lines. We show that for intermediate tunnel coupling between the dots this interaction leads to an anomalous Stark effect with an essential deviation of the recombination energy from the usual quadratic dependence on the electric field. (c) 2004 Elsevier B.V. All rights reserved. |
| 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 |
|
Wos |
000228439600029 |
Publication Date |
2004-12-06 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0022-2313; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.686 |
Times cited |
10 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 2.686; 2005 IF: 1.518 |
| Call Number |
UA @ lucian @ c:irua:103675 |
Serial |
532 |
| Permanent link to this record |
| |
|
| |
| Author |
Papp, G.; Peeters, F.M. |
| Title |
Giant magnetoresistance in a two-dimensional electron gas modulated by magnetic barriers |
Type |
A1 Journal article |
| Year |
2004 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
| Volume |
16 |
Issue |
46 |
Pages |
8275-8283 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The temperature-dependent giant magnetoresistance effect is investigated in a magnetically modulated two-dimensional electron gas, which can be realized by depositing two parallel ferromagnets on the top and bottom of a heterostructure. The effective potential for electrons arising for parallel magnetization allows the electrons to resonantly tunnel through the magnetic barriers, while this is excluded in the anti-parallel situation. Such a discrepancy results in a giant magnetoresistance ratio (MRR), which can be up to 10(31)%. The MRR shows a strong dependence on temperature, but our study indicates that for realistic parameters for a GaAs heterostructure the effect can be as high as 10(4)% at 4 K. |
| 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 |
|
Wos |
000225706000017 |
Publication Date |
2004-11-06 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0953-8984;1361-648X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.649 |
Times cited |
69 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 2.649; 2004 IF: 2.049 |
| Call Number |
UA @ lucian @ c:irua:103718 |
Serial |
1338 |
| Permanent link to this record |
| |
|
| |
| Author |
de Gryse, O.; Vanhellemont, J.; Clauws, P.; Lebedev, O.; van Landuyt, J.; Simoen, E.; Claeys, C. |
| Title |
A novel approach to analyse FTIR spectra of precipitates in boron-doped silicon |
Type |
A1 Journal article |
| Year |
2003 |
Publication |
Physica: B : condensed matter
T2 – 22nd International Conference on Defects in Semiconductors (ICDS-22), JUL 28-AUG 01, 2003, UNIV AARHUS, AARHUS, DENMARK |
Abbreviated Journal |
Physica B |
| Volume |
340 |
Issue |
|
Pages |
1013-1017 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Infrared absorption spectra of composite precipitates are analysed with a modified Day-Thorpe algorithm, assuming a precipitated phase consisting of a mixture of two components with known optical properties. Additional constraints are introduced when solving the model equations by using a priori knowledge making the algorithm more reliable. It is shown that this novel approach allows determining both morphology and composition of precipitates. The method is applied to characterise oxide precipitates in boron-doped silicon. The results indicate that for the resistivity range above 60 mOmegacm, the precipitated phase is most probably SiO1.17+/-0.14, while for resistivities below 20 mOmega cm, precipitates consist of a SiO2/B2O3 composite with a large volume fraction of B(2)0(3) (up to 40% for 8 mOmegacm material). (C) 2003 Elsevier B.V. All rights reserved. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000188300200213 |
Publication Date |
2003-11-24 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0921-4526; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.386 |
Times cited |
4 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 1.386; 2003 IF: 0.908 |
| Call Number |
UA @ lucian @ c:irua:103784 |
Serial |
25 |
| Permanent link to this record |
| |
|
| |
| Author |
Blumenau, A.T.; Jones, R.; Frauenheim, T.; Willems, B.; Lebedev, O.I.; Van Tendeloo, G.; Fisher, D.; Martineau, P.M. |
| Title |
Dislocations in diamond : dissociation into partials and their glide motion |
Type |
A1 Journal article |
| Year |
2003 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
68 |
Issue |
1 |
Pages |
014115-14119 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
The dissociation of 60degrees and screw dislocations in diamond is modeled in an approach combining isotropic elasticity theory with ab initio-based tight-binding total-energy calculations. Both dislocations are found to dissociate with a substantial lowering of their line energies. For the 60degrees dislocation, however, an energy barrier to dissociation is found. We investigate the core structure of a screw dislocation distinguishing “shuffle,” “mixed,” and “glide” cores. The latter is found to be the most stable undissociated screw dislocation. Further, the glide motion of 90degrees and 30degrees partials is discussed in terms of a process involving the thermal formation and subsequent migration of kinks along the dislocation line. The calculated activation barriers to dislocation motion show that the 30degrees partial is less mobile than the 90degrees partial. Finally, high-resolution electron microscopy is performed on high-temperature, high-pressure annealed natural brown diamond, allowing the core regions of 60degrees dislocations to be imaged. The majority of dislocations are found to be dissociated. However, in some cases, undissociated 60degrees dislocations were also observed. |
| 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 |
000184582900050 |
Publication Date |
2003-08-01 |
| Series Editor |
|
Series Title |
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Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0163-1829;1095-3795; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
39 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.836; 2003 IF: NA |
| Call Number |
UA @ lucian @ c:irua:103800 |
Serial |
734 |
| Permanent link to this record |
| |
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| |
| Author |
Ivanov, V.A.; Krstajic, P.M.; Peeters, F.M.; Fleurov, V.; Kikoin, K. |
| Title |
On the ferromagnetic exchange in Mn-doped III-V semiconductors |
Type |
A1 Journal article |
| Year |
2003 |
Publication |
Physica: B : condensed matter
T2 – 23rd International Conference on Low Temperature Physics (LT23), AUG 20-27, 2002, HIROSHIMA, JAPAN |
Abbreviated Journal |
Physica B |
| Volume |
329 |
Issue |
Part 2 |
Pages |
1282-1283 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We propose a microscopic model for double exchange in GaAs:Mn, GaP:Mn which is based on the interaction between the transition metal impurities and the heavy holes of host semiconductor. The kinematic exchange is derived and the Curie temperature is calculated which agrees with recent experiments. (C) 2003 Elsevier Science B.V. All rights reserved. |
| 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 |
|
| Language |
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Wos |
000183802700400 |
Publication Date |
2003-02-28 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0921-4526; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.386 |
Times cited |
5 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 1.386; 2003 IF: 0.908 |
| Call Number |
UA @ lucian @ c:irua:103813 |
Serial |
2435 |
| Permanent link to this record |
| |
|
| |
| Author |
Wang, Z.-H.; Kronmüller, H.; Lebedev, O.I.; Gross, G.M.; Razavi, F.S.; Habermeier, H.U.; Shen, B.G. |
| Title |
Phase transition and magnetic anisotropy of (La,Sr)MnO3 thin films |
Type |
A1 Journal article |
| Year |
2002 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
65 |
Issue |
5 |
Pages |
054411-54416 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
The magnetic proper-ties and their correlation with the microstructure and electrical transport are investigated in La0.88Sr0.1MnO3 films grown on (100)SrTiO3 Single crystal substrates with thickness ranging from 100 to 2500 Angstrom. The ultrathin film (t = 100 Angstrom) has a single ferromagnetic transition (FMT) at T-c of 250 K, whereas the thicker films exhibit two FMTs, with the main one at a lowered T-c of 200 K while the minor one around 300 K. Furthermore, a thickness dependent magnetic anisotropy has been found, strongly indicating the existence of strain effect, which is also revealed by the transmission electron microscopy study. The suppressed Jahn-Teller distortion (JTD) by the epitaxial strain, and the recovered JTD due to the strain relexation are suggested to explain the metallic behavior in thin films and the insulating behavior in the thick film (t = 2500 Angstrom), repectively. |
| 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 |
000173647000058 |
Publication Date |
2002-07-27 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0163-1829;1095-3795; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
23 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.836; 2002 IF: NA |
| Call Number |
UA @ lucian @ c:irua:103883 |
Serial |
2592 |
| Permanent link to this record |
| |
|
| |
| Author |
Baelus, B.J.; Yampolskii, S.V.; Peeters, F.M.; Montevecchi, E.; Indekeu, J.O. |
| Title |
Superconducting properties of mesoscopic cylinders with enhanced surface superconductivity |
Type |
A1 Journal article |
| Year |
2002 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
65 |
Issue |
2 |
Pages |
024510-10 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The superconducting state of an infinitely long superconducting cylinder surrounded by a medium which enhances its superconductivity near the boundary is studied within the nonlinear Ginzburg-Landau theory. This enhancement can be due to the proximity of another superconductor or due to surface treatment. Quantities such as the free energy, the magnetization and the Cooper-pair density are calculated. Phase diagrams are obtained to investigate how the critical field and the critical temperature depend on this surface enhancement for different values of the Ginzburg-Landau parameter kappa. Increasing the superconductivity near the surface leads to higher critical fields and critical temperatures. For small cylinder diameters only giant vortex states nucleate, while for larger cylinders multivortices can nucleate. The stability of these multivortex states also depends on the surface enhancement. For type-I superconductors we found the remarkable result that for a range of values of the surface extrapolation length the superconductor can transit from the Meissner state into superconducting states with vorticity L > 1. Such a behavior is not found for the case of large kappa, i.e., type-II superconductivity, |
| 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 |
000173213100099 |
Publication Date |
2002-07-27 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0163-1829;1095-3795; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
13 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.836; 2002 IF: NA |
| Call Number |
UA @ lucian @ c:irua:103890 |
Serial |
3363 |
| Permanent link to this record |
| |
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| |
| Author |
Sudheendra, L.; Moshnyaga, V.; Lebedev, O.I.; Gehrke, K.; Belenciuc, A.; Shapoval, O.; Van Tendeloo, G.; Samwer, K. |
| Title |
A-site ordering and stripe phases in manganite films |
Type |
A1 Journal article |
| Year |
2008 |
Publication |
Physica: B : condensed matter
T2 – International Conference on Strongly Correlated Electron Systems (SCES, 2007), MAY 13-18, 2007, Houston, TX |
Abbreviated Journal |
Physica B |
| Volume |
403 |
Issue |
5-9 |
Pages |
1645-1646 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Insulating and metallic stripes above and below the Curie temperature, T-C, respectively, were observed by a high-resolution scanning tunneling microscopy (STM) and/or spectroscopy (STS) in A-site ordered and macroscopically strain free epitaxial La0.75Ca0.25MnO3 film grown on MgO substrate. The “insulating” stripes were found to be incommensurable to the lattice and aligned along (110) direction. Metallic stripes were commensurable with periodicity 2a(p)similar to 0.8 nm and aligned parallel to the crystallographic a/b-axis. Formation of these stripes involves competing charge, orbital, and lattice orders and is an outcome of an overlapping of electron wave functions mediated by the local lattice-strain distribution, existed even in A-site ordered film due to the difference in cation radii of La and Ca. (C) 2007 Elsevier B.V. All rights reserved. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000254689900330 |
Publication Date |
2007-11-06 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0921-4526; |
ISBN |
|
Additional Links |
UA library record; WoS full record |
| Impact Factor |
1.386 |
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 1.386; 2008 IF: 0.822 |
| Call Number |
UA @ lucian @ c:irua:104031 |
Serial |
26 |
| Permanent link to this record |
| |
|
| |
| Author |
Dzhurakhalov, A.A.; Atanasov, I.; Hou, M. |
| 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 |
| Volume |
|
Issue |
|
Pages |
115415 |
| Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
| 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. |
| Address |
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| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
| Language |
|
Wos |
000254542800167 |
Publication Date |
2008-03-11 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1098-0121; 1550-235x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
11 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.836; 2008 IF: 3.322 |
| Call Number |
UA @ lucian @ c:irua:104033 |
Serial |
4517 |
| Permanent link to this record |
| |
|
| |
| Author |
Vagov, A.; Schomerus, H.; Shanenko, A. |
| Title |
Generalized Galitskii approach for the vertex function of a Fermi gas with resonant interaction |
Type |
A1 Journal article |
| Year |
2007 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
76 |
Issue |
21 |
Pages |
214513-214517 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We present a generalized Galitskii approach for the Bethe-Salpeter equation for the two-particle vertex function of a Fermi system with the resonant interaction by accounting for the resonant state in the scattering potential and utilizing the universal form of the resonant scattering amplitude. The procedure can be carried out both for the normal as well as for the condensate state. In both cases, the vertex function in the vicinity of the resonance is shown to formally coincide with that obtained for a weakly attractive Fermi gas. Thus we justify the popular calculational framework in which results for the weakly attractive Fermi gas are formally extrapolated into the domain of strong coupling, and further to the repulsive side of the resonance, where molecular states are formed. |
| Address |
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| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000251986100097 |
Publication Date |
2007-12-28 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
8 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.836; 2007 IF: 3.172 |
| Call Number |
UA @ lucian @ c:irua:104037 |
Serial |
1324 |
| Permanent link to this record |
| |
|
| |
| Author |
Krstajic, P.; Peeters, F.M. |
| 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 |
| Volume |
72 |
Issue |
12 |
Pages |
125350-125356 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| 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. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000232229400116 |
Publication Date |
2005-09-30 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
8 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.836; 2005 IF: 3.185 |
| Call Number |
UA @ lucian @ c:irua:104068 |
Serial |
3086 |
| Permanent link to this record |
| |
|
| |
| Author |
Verberck, B.; Nikolaev, A.V.; Michel, K.H. |
| Title |
Orientational charge density waves and the metal-insulator transition in polymerized KC60 |
Type |
A1 Journal article |
| Year |
2005 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
71 |
Issue |
16 |
Pages |
165117-11 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
A theoretical model is presented for the description of the metal-insulator transition which accompanies the structural phase transition at T approximate to 50 K in polymerized KC60. The model involves orientational charge density waves (along the C-60 polymer chains) which were introduced previously for a description of the structural phase transition. A satisfactory qualitative and quantitative understanding is obtained when the three-dimensionality of the crystal and the presence of the K+ counterions is properly taken into account. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
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Editor |
|
| Language |
|
Wos |
000228763100035 |
Publication Date |
2005-04-27 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
1 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.836; 2005 IF: 3.185 |
| Call Number |
UA @ lucian @ c:irua:104076 |
Serial |
2514 |
| Permanent link to this record |
| |
|
| |
| Author |
Peeters, F.M.; Vasilopoulos, P.; Shi, J. |
| 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 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| 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. |
| Address |
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| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
London |
Editor |
|
| Language |
|
Wos |
000178678400008 |
Publication Date |
2002-09-18 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0953-8984; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.649 |
Times cited |
8 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 2.649; 2002 IF: 1.775 |
| Call Number |
UA @ lucian @ c:irua:104140 |
Serial |
640 |
| Permanent link to this record |
| |
|
| |
| Author |
Vodolazov, D.Y.; Baelus, B.J.; Peeters, F.M. |
| 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. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000177873000137 |
Publication Date |
2002-10-01 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0163-1829;1095-3795; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
29 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.836; 2002 IF: NA |
| Call Number |
UA @ lucian @ c:irua:104147 |
Serial |
3152 |
| Permanent link to this record |
| |
|
| |
| Author |
Anisimovas, E.; Peeters, F.M. |
| 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 |
| Volume |
65 |
Issue |
23 |
Pages |
233302-233304 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| 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. |
| 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 |
000176767900019 |
Publication Date |
2002-07-27 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| 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 |
| Permanent link to this record |
| |
|
| |
| Author |
Maignan, A.; Martin, C.; Van Tendeloo, G.; Hervieu, M.; Raveau, B. |
| 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 |
| Volume |
60 |
Issue |
22 |
Pages |
15214-15219 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| 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]. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000084631600039 |
Publication Date |
2002-07-27 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| 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 |
| Call Number |
UA @ lucian @ c:irua:104280 |
Serial |
3038 |
| Permanent link to this record |
| |
|
| |
| Author |
Seo, J.W.; Schryvers, D.; Vermeulen, W.; Richard, O.; Potapov, P. |
| Title |
Electron microscopy investigation of ternary \gamma-brass-type precipitation in a Ni39.6Mn47.5Ti12.9 alloy |
Type |
A1 Journal article |
| Year |
1999 |
Publication |
Philosophical magazine: A: physics of condensed matter: defects and mechanical properties |
Abbreviated Journal |
Philos Mag A |
| Volume |
79 |
Issue |
6 |
Pages |
1279-1294 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Laboratory Experimental Medicine and Pediatrics (LEMP) |
| Abstract |
Homogenized Ni39.6Mn47.5T12.9 material was investigated by different electron microscopy techniques. Apart from the martensite precursor distortions typical for B2 phase alloys undergoing a thermoelastic martensitic transformation upon cooling, coherent dodecahedron-shaped precipitates with sizes between 20 and 100 nm and faceted by lozenge shapes of {110}-type planes are observed. Selected-area and microdiffraction patterns reveal an overall unit cell with a size of 3 x 3 x 3 units of the bcc lattice of the matrix and a body-centred symmetry without screw axes. Finally a ternary gamma-brass-type atomic structure of space group 14(3) over bar m is suggested for these precipitates in accordance with the obtained symmetry constraints, the energy-dispersive X-ray measurements and high-resolution transmission electron microscopy images. This is the first time this type of structure is found in an alloy completely consisting of transition-metal elements. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
London |
Editor |
|
| Language |
|
Wos |
000080687900002 |
Publication Date |
2007-07-08 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0141-8610;1460-6992; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
|
Times cited |
3 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: NA |
| Call Number |
UA @ lucian @ c:irua:104297 |
Serial |
956 |
| Permanent link to this record |
| |
|
| |
| Author |
Copley, J.R.D.; Michel, K.H. |
| Title |
Multiple orientational order parameters in solid C60 |
Type |
A1 Journal article |
| Year |
1997 |
Publication |
Physica: B : condensed matter
T2 – International Conference on Neutron Scattering, AUG 17-21, 1997, TORONTO, CANADA |
Abbreviated Journal |
Physica B |
| Volume |
241 |
Issue |
|
Pages |
454-455 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The transition Fm (3) over bar m -->Pa (3) over bar in solid C-60 is driven by the condensation of orientational modes belonging to X-5(+) irreducible representations (irreps) of Fm (3) over bar m. Taking into account irreps up to the manifold l = 12, we have studied the primary and secondary orientational order parameters loops). We have numerically solved the coupled molecular field equations for these oops and calculated the temperature dependence of Bragg reflection intensities. (C) 1998 Elsevier Science B.V. All rights reserved. |
| 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 |
|
| Language |
|
Wos |
000074062600130 |
Publication Date |
2002-07-25 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0921-4526; |
ISBN |
|
Additional Links |
UA library record; WoS full record |
| Impact Factor |
1.386 |
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 1.386; 1997 IF: 0.991 |
| Call Number |
UA @ lucian @ c:irua:104360 |
Serial |
2228 |
| Permanent link to this record |
| |
|
| |
| Author |
Callebaut, A.K.; Michel, K.H. |
| Title |
Microscopic theory of orientational disorder and lattice instability in solid C70 |
Type |
A1 Journal article |
| Year |
1995 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
52 |
Issue |
21 |
Pages |
15279-15290 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We have developed a microscopic theory which describes the orientational dynamics of C-70 molecules and its coupling to lattice displacements in the face-centered-cubic phase of C-70 fullerite. The single-molecule orientational density distribution in the disordered phase is calculated. The ferroelastic transition to the rhombohedral phase is investigated. The discontinuity of the orientational order parameter at the phase transition is calculated. It is found that the transition leads to a stretching of the primitive unit cell along a [111] cubic direction. A softening of the elastic constant c(44) at the transition is predicted. |
| 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 |
|
| Language |
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Wos |
A1995TK97900042 |
Publication Date |
2002-07-27 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0163-1829;1095-3795; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.736 |
Times cited |
20 |
Open Access |
|
| Notes |
|
Approved |
PHYSICS, APPLIED 28/145 Q1 # |
| Call Number |
UA @ lucian @ c:irua:104421 |
Serial |
2031 |
| Permanent link to this record |
| |
|
| |
| Author |
Beheshtian, J.; Sadeghi, A.; Neek-Amal, M.; Michel, K.H.; Peeters, F.M. |
| Title |
Induced polarization and electronic properties of carbon-doped boron nitride nanoribbons |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
86 |
Issue |
19 |
Pages |
195433-195438 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| 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. |
| 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 |
000311694200006 |
Publication Date |
2012-11-29 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
41 |
Open Access |
|
| 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 |
| Call Number |
UA @ lucian @ c:irua:105136 |
Serial |
1603 |
| Permanent link to this record |
| |
|
| |
| Author |
Sarmadian, N.; Saniz, R.; Lamoen, D.; Partoens, B. |
| Title |
Influence of Al concentration on the optoelectronic properties of Al-doped MgO |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
86 |
Issue |
20 |
Pages |
205129-5 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
| Abstract |
We use density functional theory within the local density approximation to investigate the structural, electronic, and optical properties of Al-doped MgO. The concentrations considered range from 6% to 56%. In the latter case, we also compare the optical properties of the amorphous and crystalline phases. We find that, overall, the electronic properties of the crystalline phases change qualitatively little with Al concentration. On the other hand, the changes in the electronic structure in the amorphous phase are more important, most notably because of deep impurity levels in the band gap that are absent in the crystalline phase. This leads to observable effects in, e.g., the optical absorption edge and in the refractive index. Thus, the latter can be used to characterize the crystalline to amorphous transition with Al doping level. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000311605000003 |
Publication Date |
2012-11-28 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
5 |
Open Access |
|
| Notes |
Iwt; Fwo |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
| Call Number |
UA @ lucian @ c:irua:105137 |
Serial |
1612 |
| Permanent link to this record |
| |
|
| |
| Author |
Muñoz, W.A.; Covaci, L.; Peeters, F.M. |
| Title |
Tight-binding study of bilayer graphene Josephson junctions |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
86 |
Issue |
18 |
Pages |
184505-184507 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| 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. |
| Address |
|
| Corporate Author |
|
Thesis |
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| Publisher |
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Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000310840400005 |
Publication Date |
2012-11-07 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
13 |
Open Access |
|
| Notes |
; This work was supported by the Flemish Science Foundation (FWO-VI). ; |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
| Call Number |
UA @ lucian @ c:irua:105149 |
Serial |
3661 |
| Permanent link to this record |
| |
|
| |
| Author |
Galván Moya, J.E.; Nelissen, K.; Peeters, F.M. |
| Title |
Structural transitions in vertically and horizontally coupled parabolic channels of Wigner crystals |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
86 |
Issue |
18 |
Pages |
184102-184109 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| 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. |
| Address |
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| Corporate Author |
|
Thesis |
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| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000310683600002 |
Publication Date |
2012-11-05 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
6 |
Open Access |
|
| Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl). ; |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
| Call Number |
UA @ lucian @ c:irua:105150 |
Serial |
3271 |
| Permanent link to this record |
| |
|
| |
| Author |
Dixit, H.; Lamoen, D.; Partoens, B. |
| Title |
Quasiparticle band structure of rocksalt-CdO determined using maximally localized Wannier functions |
Type |
A1 Journal article |
| Year |
2013 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
| Volume |
25 |
Issue |
3 |
Pages |
035501-35505 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
| Abstract |
CdO in the rocksalt structure is an indirect band gap semiconductor. Thus, in order to determine its band gap one needs to calculate the complete band structure. However, in practice, the exact evaluation of the quasiparticle band structure for the large number of k-points which constitute the different symmetry lines in the Brillouin zone can be an extremely demanding task compared to the standard density functional theory (DFT) calculation. In this paper we report the full quasiparticle band structure of CdO using a plane-wave pseudopotential approach. In order to reduce the computational effort and time, we make use of maximally localized Wannier functions (MLWFs). The MLWFs offer a highly accurate method for interpolation of the DFT or GW band structure from a coarse k-point mesh in the irreducible Brillouin zone, resulting in a much reduced computational effort. The present paper discusses the technical details of the scheme along with the results obtained for the quasiparticle band gap and the electron effective mass. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
London |
Editor |
|
| Language |
|
Wos |
000313100500010 |
Publication Date |
2012-12-12 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0953-8984;1361-648X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.649 |
Times cited |
7 |
Open Access |
|
| Notes |
Fwo |
Approved |
Most recent IF: 2.649; 2013 IF: 2.223 |
| Call Number |
UA @ lucian @ c:irua:105296 |
Serial |
2801 |
| Permanent link to this record |
| |
|
| |
| Author |
Vodolazov, D.Y.; Peeters, F.M. |
| Title |
Origin of the hysteresis of the current voltage characteristics of superconducting microbridges near the critical temperature |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
84 |
Issue |
9 |
Pages |
094511 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The current voltage (IV) characteristics of short [with length L less than or similar to xi(T)] and long [L >> xi(T)] microbridges are theoretically investigated near the critical temperature of the superconductor. Calculations are made in the nonlocal (local) limit when the inelastic relaxation length due to electron-phonon interactions L(in) = (D tau(in))(1/2) is larger (smaller) than the temperature-dependent coherence length xi(T) (D is the diffusion coefficient, tau(in) is the inelastic relaxation time of the quasiparticle distribution function). We find that, in both limits, the origin of the hysteresis in the IV characteristics is mainly connected with the large time scale over which the magnitude of the order parameter varies in comparison with the time-scale variation of the superconducting phase difference across the microbridge in the resistive state. In the nonlocal limit, the time-averaged heating and cooling of quasiparticles are found in different areas of the microbridge, which are driven, respectively, by oscillations of the order parameter and the electric field. We show that, by introducing an additional term in the time-dependent Ginzburg-Landau equation, it is possible to take into account the cooling effect in the local limit too. |
| Address |
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| Corporate Author |
|
Thesis |
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| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000294920900009 |
Publication Date |
2011-09-14 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
7 |
Open Access |
|
| Notes |
; This work was supported by the Russian Foundation for Basic Research, Russian Agency of Education under the Federal Target Programme“Scientific and educational personnel of innovative Russia in 2009-2013,” the Flemish Science Foundation (FWO-Vl), and the Belgian Science Policy (IAP). ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
| Call Number |
UA @ lucian @ c:irua:105573 |
Serial |
2527 |
| Permanent link to this record |
| |
|
| |
| Author |
Sofo, J.O.; Suarez, A.M.; Usaj, G.; Cornaglia, P.S.; Hernández-Nieves, A.D.; Balseiro, C.A. |
| Title |
Electrical control of the chemical bonding of fluorine on graphene |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
83 |
Issue |
8 |
Pages |
081411 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We study the electronic structure of diluted F atoms chemisorbed on graphene using density functional theory calculations. We show that the nature of the chemical bonding of a F atom adsorbed on top of a C atom in graphene strongly depends on carrier doping. In neutral samples the F impurities induce a sp(3)-like bonding of the C atom below, generating a local distortion of the hexagonal lattice. As the graphene is electron-doped, the C atom retracts back to the graphene plane and for high doping (10(14) cm(-2)) its electronic structure corresponds to a nearly pure sp(2) configuration. We interpret this sp(3)-sp(2) doping-induced crossover in terms of a simple tight-binding model and discuss the physical consequences of this change. |
| Address |
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| Corporate Author |
|
Thesis |
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| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000287484800005 |
Publication Date |
2011-02-18 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
65 |
Open Access |
|
| Notes |
; J.O.S. and A. S. acknowledge support from the Donors of the American Chemical Society Petroleum Research Fund and use of facilities at the Penn State Materials Simulation Center. G. U., P. S. C., A. D. H., and C. A. B. acknowledge financial support from PICTs 06-483 and 2008-2236 from ANPCyT and PIP 11220080101821 from CONICET, Argentina. A. D. H. acknowledges support from the Flemish Science Foundation (FWO). ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
| Call Number |
UA @ lucian @ c:irua:105600 |
Serial |
892 |
| Permanent link to this record |
