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Author |
Lobato, I.; Partoens, B. |
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Title |
Multiple Dirac particles in AA-stacked graphite and multilayers of graphene |
Type |
A1 Journal article |
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Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
83 |
Issue |
16 |
Pages |
165429-165429,9 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
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Abstract |
Using the tight-binding formalism we show that in the recently experimentally realized AA-stacked graphite in essence two types of massless relativistic Dirac particles are present with a different effective speed of light. We also investigate how the electronic structure evolves from a single graphene sheet into AA-stacked graphite. It is shown that in contrast to AB-stacked graphene layers, the spectrum of AA-stacked graphene layers can be considered as a superposition of single-layer spectra and only particles with a linear spectrum at the Fermi energy around the K point are present. From the evolution of the band overlap we show that 6 multilayers of AA-stacked graphene already behave as AA-stacked graphite. The evolution of the effective speeds of light of the Dirac particles to their bulk values shows exactly the same behavior. The tight-binding parameters we use to describe AA-stacked graphite and multilayers of graphene are obtained by ab initio calculations. |
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Wos |
000290113900005 |
Publication Date |
2011-04-21 |
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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 |
68 |
Open Access |
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Notes |
; ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
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Call Number |
UA @ lucian @ c:irua:89717 |
Serial |
2225 |
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Permanent link to this record |
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Author |
Vodolazov, D.Y.; Peeters, F.M.; Dubonos, S.V.; Geim, A.K. |
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Title |
Multiple flux jumps and irreversible behavior of thin Al superconducting rings |
Type |
A1 Journal article |
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Year |
2003 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
67 |
Issue |
5 |
Pages |
054506-6 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
An experimental and theoretical investigation was made of flux jumps and irreversible magnetization curves of mesoscopic Al superconducting rings. In the small magnetic-field region the change of vorticity with magnetic field can be larger than unity. This behavior is connected with the existence of several metastable states of different vorticities. The intentional introduction of a defect in the ring has a large effect on the size of the flux jumps. Calculations based on the time-dependent Ginzburg-Landau model allows us to explain the experimental results semiquantitatively. |
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Wos |
000181360300061 |
Publication Date |
2003-02-22 |
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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 |
0163-1829;1095-3795; |
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 |
49 |
Open Access |
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Notes |
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Approved |
Most recent IF: 3.836; 2003 IF: NA |
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Call Number |
UA @ lucian @ c:irua:102812 |
Serial |
2227 |
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Permanent link to this record |
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Author |
Jorissen, K.; Rehr, J.J.; Verbeeck, J. |
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Title |
Multiple scattering calculations of relativistic electron energy loss spectra |
Type |
A1 Journal article |
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Year |
2010 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
81 |
Issue |
15 |
Pages |
155108,1-155108,6 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
A generalization of the real-space Greens-function approach is presented for ab initio calculations of relativistic electron energy loss spectra (EELS) which are particularly important in anisotropic materials. The approach incorporates relativistic effects in terms of the transition tensor within the dipole-selection rule. In particular, the method accounts for relativistic corrections to the magic angle in orientation resolved EELS experiments. The approach is validated by a study of the graphite C K edge, for which we present an accurate magic angle measurement consistent with the predicted value. |
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Wos |
000277210500038 |
Publication Date |
2010-04-13 |
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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 |
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 |
24 |
Open Access |
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Notes |
Fwo; Esteem 026019 |
Approved |
Most recent IF: 3.836; 2010 IF: 3.774 |
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Call Number |
UA @ lucian @ c:irua:82805UA @ admin @ c:irua:82805 |
Serial |
2230 |
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Permanent link to this record |
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Author |
Abakumov, A.M.; Tsirlin, A.A.; Bakaimi, I.; Van Tendeloo, G.; Lappas, A. |
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Title |
Multiple twinning as a structure directing mechanism in layered rock-salt-type oxides : NaMnO2 polymorphism, redox potentials, and magnetism |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
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Volume |
26 |
Issue |
10 |
Pages |
3306-3315 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
New polymorphs of NaMnO2 have been observed using transmission electron microscopy and synchrotron X-ray powder diffraction. Coherent twin planes confined to the (NaMnO2) layers, parallel to the (10 (1) over bar) crystallographic planes of the monoclinic layered rock-salt-type alpha-NaMnO2 (O3) structure, form quasi-periodic modulated sequences, with the known alpha-and beta-NaMnO2 polymorphs as the two limiting cases. The energy difference between the polymorphic forms, estimated using a DFT-based structure relaxation, is on the scale of the typical thermal energies that results in a high degree of stacking disorder in these compounds. The results unveil the remarkable effect of the twin planes on both the magnetic and electrochemical properties. The polymorphism drives the magnetic ground state from a quasi-1D spin system for the geometrically frustrated alpha-polymorph through a two-leg spin ladder for the intermediate stacking sequence toward a quasi-2D magnet for the beta-polymorph. A substantial increase of the equilibrium potential for Na deintercalation upon increasing the concentration of the twin planes is calculated, providing a possibility to tune the electrochemical potential of the layered rock-salt ABO(2) cathodes by engineering the materials with a controlled concentration of twins. |
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Wos |
000336637000036 |
Publication Date |
2014-05-01 |
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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 |
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Series Issue |
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Edition |
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ISSN |
0897-4756;1520-5002; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
9.466 |
Times cited |
35 |
Open Access |
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Notes |
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Approved |
Most recent IF: 9.466; 2014 IF: 8.354 |
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Call Number |
UA @ lucian @ c:irua:117766 |
Serial |
2232 |
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Permanent link to this record |
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Author |
Neek-Amal, M.; Peeters, F.M. |
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Title |
Nanoindentation of a circular sheet of bilayer graphene |
Type |
A1 Journal article |
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Year |
2010 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
81 |
Issue |
23 |
Pages |
235421,1-235421,6 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Nanoindentation of bilayer graphene is studied using molecular-dynamics simulations. We compared our simulation results with those from elasticity theory as based on the nonlinear Föppl-Hencky equations with rigid boundary condition. The force-deflection values of bilayer graphene are compared to those of monolayer graphene. Youngs modulus of bilayer graphene is estimated to be 0.8 TPa which is close to the value for graphite. Moreover, an almost flat bilayer membrane at low temperature under central load has a 14% smaller Youngs modulus as compared to the one at room temperature. |
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Wos |
000278710800003 |
Publication Date |
2010-06-11 |
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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 |
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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 |
108 |
Open Access |
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Notes |
; We gratefully acknowledge comments from R. Asgari. M.N.-A. would like to thank the Universiteit of Antwerpen for its hospitality where part of this work was performed. This work was supported by the Flemish science foundation (FWO-V1) and the Belgium Science Policy (IAP). ; |
Approved |
Most recent IF: 3.836; 2010 IF: 3.774 |
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Call Number |
UA @ lucian @ c:irua:83093 |
Serial |
2259 |
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Permanent link to this record |
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Author |
Cheng, J.P.; Zhang, X.B.; Ye, Y.; Tao, X.Y.; Liu, F.; Li, Y.; Van Tendeloo, G. |
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Title |
Natural mineral-marine manganese nodule as a novel catalyst for the synthesis of carbon nanotubes |
Type |
A1 Journal article |
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Year |
2006 |
Publication |
Journal of Wuhan University of Technology: materials science edition |
Abbreviated Journal |
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Volume |
21 |
Issue |
1 |
Pages |
29-31 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
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Wos |
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Publication Date |
0000-00-00 |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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ISSN |
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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 |
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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:57740 |
Serial |
2286 |
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Permanent link to this record |
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Author |
Rotaru, G.-M.; Schryvers, D. |
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Title |
New (3(3)under-bar) long-period microtwin variant in the martensitic phase of the PtTi alloy |
Type |
A1 Journal article |
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Year |
2008 |
Publication |
Materials science and engineering: part A: structural materials: properties, microstructure and processing |
Abbreviated Journal |
Mat Sci Eng A-Struct |
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Volume |
481 |
Issue |
Si |
Pages |
437-441 |
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Keywords |
A1 Journal article; 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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Place of Publication |
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Language |
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Wos |
000255716100090 |
Publication Date |
2007-06-07 |
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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 |
0921-5093; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.094 |
Times cited |
3 |
Open Access |
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Notes |
Multimat |
Approved |
Most recent IF: 3.094; 2008 IF: 1.806 |
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Call Number |
UA @ lucian @ c:irua:69140 |
Serial |
2300 |
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Permanent link to this record |
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Author |
Afanasov, I.M.; Lebedev, O.I.; Kolozhvary, B.A.; Smirnov, A.V.,; Van Tendeloo, G. |
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Title |
Nickel/carbon composite materials based on expanded graphite |
Type |
A1 Journal article |
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Year |
2011 |
Publication |
New carbon materials |
Abbreviated Journal |
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Volume |
26 |
Issue |
5 |
Pages |
335-340 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Monolithic nickel/carbon (Ni/C) composites were prepared from coal tar pitch-impregnated compressed expanded graphite pre-decorated with NiO particles (EGNiO) by pyrolysis at 550 °C and subsequent steam activation at 800 °C. The microstructural arrangement of the Ni-comprising nanoparticles in the composites was investigated using transmission electron microscopy. The specific surface area and porosity of the composites were analyzed by nitrogen adsorption. The catalytic activity of the composites was compared with the material obtained by the conventional H2 treatment of EGNiO using hydrocracking of 2,2,3-trimethylpentane as a model reaction. |
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Wos |
000296926500003 |
Publication Date |
2011-11-12 |
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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 |
1872-5805; |
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 |
Iap |
Approved |
Most recent IF: NA |
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Call Number |
UA @ lucian @ c:irua:93633 |
Serial |
2340 |
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Permanent link to this record |
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Author |
Blin, J.L.; Becue, A.; Pauwels, B.; Van Tendeloo, G.; Su, B.L. |
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Title |
Non-ionic surfactant (C13EOm, m=6, 12 and 18) for large pore mesoporous molecular sieves preparation |
Type |
A1 Journal article |
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Year |
2001 |
Publication |
Microporous and mesoporous materials |
Abbreviated Journal |
Micropor Mesopor Mat |
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Volume |
44/45 |
Issue |
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Pages |
41-51 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
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Corporate Author |
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Publisher |
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Place of Publication |
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Language |
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Wos |
000169557700007 |
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 |
1387-1811; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.615 |
Times cited |
27 |
Open Access |
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Notes |
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Approved |
Most recent IF: 3.615; 2001 IF: 2.497 |
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Call Number |
UA @ lucian @ c:irua:54789 |
Serial |
2346 |
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Permanent link to this record |
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Author |
Esfahani, D.N.; Covaci, L.; Peeters, F.M. |
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Title |
Nonlinear response to electric field in extended Hubbard models |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
90 |
Issue |
20 |
Pages |
205121 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The electric-field response of a one-dimensional ring of interacting fermions, where the interactions are described by the extended Hubbard model, is investigated. By using an accurate real-time propagation scheme based on the Chebyshev expansion of the evolution operator, we uncover various nonlinear regimes for a range of interaction parameters that allows modeling of metallic and insulating (either charge density wave or spin density wave insulators) rings. The metallic regime appears at the phase boundary between the two insulating phases and provides the opportunity to describe either weakly or strongly correlated metals. We find that the fidelity susceptibility of the ground state as a function of magnetic flux piercing the ring provides a very good measure of the short-time response. Even completely different interacting regimes behave in a similar manner at short time scales as long as the ground-state fidelity susceptibility is the same. Depending on the strength of the electric field we find various types of responses: persistent currents in the insulating phase, a dissipative regime, or damped Bloch-like oscillations with varying frequencies or even irregular in nature. Furthermore, we also consider the dimerization of the ring and describe the response of a correlated band insulator. In this case the distribution of the energy levels is more clustered and the Bloch-like oscillations become even more irregular. |
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Wos |
000345423300002 |
Publication Date |
2014-11-15 |
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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 |
3 |
Open Access |
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Notes |
; This work was supported by the Flemish Science Foundation (Fonds Wetenschappelijk Onderzoek – FWO) and the Methusalem program of the Flemish government. One of us (L. C.) receives support as a postdoctoral fellow of the FWO. ; |
Approved |
Most recent IF: 3.836; 2014 IF: 3.736 |
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Call Number |
UA @ lucian @ c:irua:122204 |
Serial |
2355 |
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Permanent link to this record |
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Author |
Schryvers, D.; Ma, Y.; Toth, L.; Tanner, L.E. |
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Title |
Nucleation and growth of Ni5Al3 in austenite and martensite matrices |
Type |
P1 Proceeding |
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Year |
1994 |
Publication |
Electron Microscopy 1994, Vols 2a And 2b: Applications In Materials Sciences |
Abbreviated Journal |
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Volume |
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Issue |
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Pages |
509-510 |
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Keywords |
P1 Proceeding; Electron microscopy for materials research (EMAT) |
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Abstract |
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Wos |
A1994BE09Y00247 |
Publication Date |
0000-00-00 |
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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 |
2-86883-226-1 |
ISBN |
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Additional Links |
UA library record; WoS full record; |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
no |
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Call Number |
UA @ lucian @ c:irua:104476 |
Serial |
2386 |
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Permanent link to this record |
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Author |
Oleshko, V.P.; Gijbels, R.H.; van Daele, A.J.; Jacob, W.A. |
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Title |
On estimation of the dielectric function of Ag(Br,I) nanocrystals by cryo-EELS (addendum) |
Type |
A3 Journal article |
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Year |
1999 |
Publication |
Nanostructered materials |
Abbreviated Journal |
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Volume |
11 |
Issue |
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Pages |
687-688 |
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Keywords |
A3 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Publication Date |
0000-00-00 |
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Additional Links |
UA library record |
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Impact Factor |
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Times cited |
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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:28332 |
Serial |
2431 |
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Permanent link to this record |
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Author |
Schryvers, D.; Tanner, L.E. |
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Title |
On the phase-like nature of the 7M structure in Ni-Al |
Type |
A3 Journal article |
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Year |
1993 |
Publication |
MRS Japan: shape memory materials |
Abbreviated Journal |
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Volume |
18 |
Issue |
B |
Pages |
849-852 |
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Keywords |
A3 Journal article; 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 |
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Place of Publication |
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Wos |
A1994BC69J00183 |
Publication Date |
0000-00-00 |
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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 |
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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 |
1 |
Open Access |
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Notes |
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Approved |
no |
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|
Call Number |
UA @ lucian @ c:irua:48356 |
Serial |
2447 |
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Permanent link to this record |
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Author |
Xu, W.; Dong, H.M.; Li, L.L.; Yao, J.Q.; Vasilopoulos, P.; Peeters, F.M. |
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Title |
Optoelectronic properties of graphene in the presence of optical phonon scattering |
Type |
A1 Journal article |
|
Year |
2010 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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|
Volume |
82 |
Issue |
12 |
Pages |
125304-125304,9 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We study in detail the optoelectronic properties of graphene. Considering the electron interactions with photons and phonons, we employ the mass- and energy-balance equations to self-consistently evaluate the photoinduced carrier densities, the optical conductance, and the transmission coefficient in the presence of a linearly polarized radiation field. We demonstrate that the photoinduced carrier densities increase around the electron-photon-phonon resonant transition. They depend strongly on the radiation intensity and frequency, temperature, and dark carrier density. For short-wavelength radiation (L<3 μm), we obtain the universal optical conductance σ0=e2/(4ℏ). Importantly, there exists an optical-absorption window in the radiation wavelength range 4100 μm, which is induced by different transition energies required for interband and intraband optical absorption. The position and width of this window depend sensitively on the temperature and the carrier density of the system. These theoretical results are in line with recent experimental findings and indicate that graphene exhibits important features not only in the visible regime but also in the midinfrared bandwidth. |
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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 |
000281516500009 |
Publication Date |
2010-09-03 |
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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 |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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|
Impact Factor |
3.836 |
Times cited |
28 |
Open Access |
|
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|
Notes |
; This work was supported by the Chinese Academy of Sciences, National Natural Science Foundation of China, and Department of Science and Technology of Yunnan Province. ; |
Approved |
Most recent IF: 3.836; 2010 IF: 3.774 |
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Call Number |
UA @ lucian @ c:irua:84260 |
Serial |
2496 |
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Permanent link to this record |
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Author |
Grujić, M.M.; Tadić, M.Z.; Peeters, F.M. |
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Title |
Orbital magnetic moments in insulating Dirac systems : impact on magnetotransport in graphene van der Waals heterostructures |
Type |
A1 Journal article |
|
Year |
2014 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
|
|
Volume |
90 |
Issue |
20 |
Pages |
205408 |
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|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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|
Abstract |
In honeycomb Dirac systems with broken inversion symmetry, orbital magnetic moments coupled to the valley degree of freedom arise due to the topology of the band structure, leading to valley-selective optical dichroism. On the other hand, in Dirac systems with prominent spin-orbit coupling, similar orbital magnetic moments emerge as well. These moments are coupled to spin, but otherwise have the same functional form as the moments stemming from spatial inversion breaking. After reviewing the basic properties of these moments, which are relevant for a whole set of newly discovered materials, such as silicene and germanene, we study the particular impact that these moments have on graphene nanoengineered barriers with artificially enhanced spin-orbit coupling. We examine transmission properties of such barriers in the presence of a magnetic field. The orbital moments are found to manifest in transport characteristics through spin-dependent transmission and conductance, making them directly accessible in experiments. Moreover, the Zeeman-type effects appear without explicitly incorporating the Zeeman term in the models, i.e., by using minimal coupling and Peierls substitution in continuum and the tight-binding methods, respectively. We find that a quasiclassical view is able to explain all the observed phenomena. |
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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 |
000344915800009 |
Publication Date |
2014-11-10 |
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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 |
|
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 |
5 |
Open Access |
|
|
|
Notes |
; This work was supported by the Ministry of Education, Science and Technological Development (Serbia), and the Fonds Wetenschappelijk Onderzoek (Belgium). ; |
Approved |
Most recent IF: 3.836; 2014 IF: 3.736 |
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Call Number |
UA @ lucian @ c:irua:122141 |
Serial |
2497 |
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Permanent link to this record |
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Author |
Nistor, L.; Van Tendeloo, G.; Amelinckx, S.; Shpanchenko, R.V.; van Landuyt, J. |
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Title |
Ordering and defects in BanTaxTiyO3n ternary oxides |
Type |
P1 Proceeding |
|
Year |
1994 |
Publication |
Electron Microscopy 1994, Vols 2a And 2b: Applications In Materials Sciences |
Abbreviated Journal |
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Volume |
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Issue |
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Pages |
869-870 |
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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 |
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Place of Publication |
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Editor |
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Wos |
A1994BE09Y00422 |
Publication Date |
0000-00-00 |
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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 |
2-86883-226-1 |
ISBN |
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Additional Links |
UA library record; WoS full record; |
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Impact Factor |
|
Times cited |
|
Open Access |
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Notes |
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Approved |
no |
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|
Call Number |
UA @ lucian @ c:irua:104477 |
Serial |
2504 |
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Permanent link to this record |
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Author |
Verberck, B.; Nikolaev, A.V.; Michel, K.H. |
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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 |
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|
Volume |
71 |
Issue |
16 |
Pages |
165117-11 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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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. |
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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 |
000228763100035 |
Publication Date |
2005-04-27 |
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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 |
1 |
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:104076 |
Serial |
2514 |
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Permanent link to this record |
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Author |
Verberck, B. |
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Title |
Orientational properties of C70 and C80 fullerenes in carbon nanotubes |
Type |
A1 Journal article |
|
Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
83 |
Issue |
4 |
Pages |
045405-045405,8 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We present energy calculations of a C80 molecule with D5d symmetry encapsulated in a carbon nanotube. The approximation of a continuous tube rather than a rolled-up graphene sheet, justified by comparison with atomistic calculations, allows an expansion of the energy field into symmetry-adapted rotator functions. For a given tube radius R, we observe a strong dependence of the interaction energy on the molecular tilt angle and on the molecules lateral position in the tube. We observe a transition from on-axis lying orientations to tilted orientations at R1≈6.95 Å and a subsequent transition to standing orientations at R2≈7.6 Å. For tube radii larger than R3≈8.0 Å, the molecule starts to occupy off-axis positions and assumes a lying orientation. Results are compared to the case of C70 molecules, with D5h symmetry. Our findings are consistent with recent high-resolution transmission electron microscopy measurements and are relevant for the design of new materials with tunable electronic properties. |
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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 |
000286770600010 |
Publication Date |
2011-01-20 |
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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 |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
3.836 |
Times cited |
6 |
Open Access |
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|
Notes |
; The author gratefully acknowledges discussions with A. V. Nikolaev and K. H. Michel. This work was financially supported by the Research Foundation-Flanders (FWO-Vl). ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
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Call Number |
UA @ lucian @ c:irua:88911 |
Serial |
2520 |
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Permanent link to this record |
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Author |
Vodolazov, D.Y.; Peeters, F.M. |
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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 |
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Volume |
84 |
Issue |
9 |
Pages |
094511 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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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. |
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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 |
000294920900009 |
Publication Date |
2011-09-14 |
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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 |
|
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 |
7 |
Open Access |
|
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|
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 |
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Call Number |
UA @ lucian @ c:irua:105573 |
Serial |
2527 |
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Permanent link to this record |
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Author |
Szaszko-Bogar, V.; Peeters, F.M.; Foeldi, P. |
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Title |
Oscillating spin-orbit interaction in two-dimensional superlattices : sharp transmission resonances and time-dependent spin-polarized currents |
Type |
A1 Journal article |
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Year |
2015 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
91 |
Issue |
91 |
Pages |
235311 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We consider ballistic transport through a lateral, two-dimensional superlattice with experimentally realizable, sinusoidally oscillating, Rashba-type spin-orbit interaction (SOI). The periodic structure of the rectangular lattice produces a spin-dependent miniband structure for static SOI. Using Floquet theory, transmission peaks are shown to appear in themini-bandgaps as a consequence of the additional, time-dependent SOI. A detailed analysis shows that this effect is due to the generation of harmonics of the driving frequency, via which, e.g., resonances that cannot be excited in the case of static SOI become available. Additionally, the transmitted current shows space-and time-dependent partial spin polarization, in other words, polarization waves propagate through the superlattice. |
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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 |
000355956500003 |
Publication Date |
2015-06-10 |
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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 |
|
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 |
10 |
Open Access |
|
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|
Notes |
; This work was partially supported by the European Union and the European Social Fund through Projects No. TAMOP-4.2.2.C-11/1/KONV-2012-0010 and No. TAMOP-4.2.2.A-11/1/KONV-2012-0060, and by the Hungarian Scientific Research Fund (OTKA) under Contracts No. T81364 and No. 116688. The ELI-ALPS Project (GOP-1.1.1-12/B-2012-0001) is supported by the European Union and cofinanced by the European Regional Development Fund. ; |
Approved |
Most recent IF: 3.836; 2015 IF: 3.736 |
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Call Number |
c:irua:126432 |
Serial |
2534 |
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Permanent link to this record |
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Author |
Scarrozza, M.; Pourtois, G.; Houssa, M.; Heyns, M.; Stesmans, A. |
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Title |
Oxidation of the GaAs(001) surface : insights from first-principles calculations |
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 |
85 |
Issue |
19 |
Pages |
195307-195307,8 |
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Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
We performed a detailed investigation of the oxidation of the technologically relevant GaAs(001)-beta 2(2x4) surface via density functional calculations. The purpose is to gain insights on the atomistic mechanisms and local bondings that underlie the degradation of the surface properties once exposed to oxygen. The study comprises the adsorption of single O atoms, through the sampling of several adsorption sites, and the subsequent formation of the O adsorbate at increasing coverage by taking into account multiple-atom adsorption. Based on the evaluation of the energetics and the structural properties of the atomistic models generated, the results here reported delineate a consistent picture of the initial stage of the surface oxidation: (i) at low coverage, in the limit of single O insertions, oxygen is incorporated on the surface forming a twofold-bridging Ga-O-As bond; (ii) at increasing coverage, as multiple O atoms are involved, this is accompanied by the formation of a threefold-coordinated bond (with two Ga and one As atoms); (iii) the latter has important implications regarding the electronic properties of the adsorbate since this O bonding may result in the formation of As dangling bonds. Moreover, a clear trend of increased energy gain for the incorporation of neighboring O atoms compared to single O insertions indicates that the formation of oxide clusters is favored over a regime of uniform oxidation. Our findings provide a detailed description of the O bonding and stress the importance of modeling the adsorption of multiple O atoms for an accurate description of the surface oxidation. |
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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 |
000303755700006 |
Publication Date |
2012-05-08 |
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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 |
|
Series Issue |
|
Edition |
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ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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|
Impact Factor |
3.836 |
Times cited |
15 |
Open Access |
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|
Notes |
|
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
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Call Number |
UA @ lucian @ c:irua:99122 |
Serial |
2538 |
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Permanent link to this record |
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Author |
Berdiyorov, G.R.; Milošević, M.V.; Savel'ev, S.; Kusmartsev, F.; Peeters, F.M. |
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Title |
Parametric amplification of vortex-antivortex pair generation in a Josephson junction |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
90 |
Issue |
13 |
Pages |
134505 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Using advanced three-dimensional simulations, we show that an Abrikosov vortex, trapped inside a cavity perpendicular to an artificial Josephson junction, can serve as a very efficient source for generation of Josephson vortex-antivortex pairs in the presence of the applied electric current. In such a case, the nucleation rate of the pairs can be tuned in a broad range by an out-of-plane ac magnetic field in a broad range of frequencies. This parametrically amplified vortex-antivortex nucleation can be considered as a macroscopic analog of the dynamic Casimir effect, where fluxon pairs mimic the photons and the ac magnetic field plays the role of the oscillating mirrors. The emerging vortex pairs in our system can be detected by the pronounced features in the measured voltage characteristics, or through the emitted electromagnetic radiation, and exhibit resonant dynamics with respect to the frequency of the applied magnetic field. Reported tunability of the Josephson oscillations can be useful for developing high-frequency emission devices. |
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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 |
000344025100003 |
Publication Date |
2014-10-06 |
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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 |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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|
Impact Factor |
3.836 |
Times cited |
22 |
Open Access |
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|
Notes |
; This work was supported by the Flemish Science Foundation (FWO-VI) and the Leverhulme Trust. G.R.B. acknowledges support from a EU-Marie Curie individual grant (Grant No. 253057) ; |
Approved |
Most recent IF: 3.836; 2014 IF: 3.736 |
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Call Number |
UA @ lucian @ c:irua:121176 |
Serial |
2553 |
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Permanent link to this record |
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Author |
Croitoru, M.D.; Shanenko, A.A.; Peeters, F.M.; Axt, V.M. |
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Title |
Parity-fluctuation induced enlargement of the ratio \DeltaE/kBTc in metallic grains |
Type |
A1 Journal article |
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Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
84 |
Issue |
21 |
Pages |
214518-214518,12 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We investigate how the interplay of quantum confinement and particle number-parity fluctuations affects superconducting correlations in ultra-small metallic grains. Using the number-parity projected BCS formalism we calculate the critical temperature and the excitation gap as a function of the grain size for grains with even and odd number of confined carriers. We show that the experimentally observed anomalous increase of the coupling ratio ΔE/kBTc with decreasing superconducting grain size can be attributed to an enhancement of the number-parity fluctuations in ultra-small grains. |
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Corporate Author |
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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 |
000298114100003 |
Publication Date |
2011-12-16 |
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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 |
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Series Issue |
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Edition |
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ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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|
Impact Factor |
3.836 |
Times cited |
14 |
Open Access |
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|
Notes |
; This work was supported by the European Community under a Marie Curie IEF Action (Grant Agreement No. PIEF-GA-2009-235486-ScQSR), the Flamish Science Foundation (FWO-Vl), and the Belgian Science Policy (IAP). M. D. C. thanks A. S. Mel'nikov and N. B. Kopnin for fruitful discussions. ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
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Call Number |
UA @ lucian @ c:irua:94373 |
Serial |
2555 |
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Permanent link to this record |
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Author |
Croitoru, M.D.; Buzdin, A.I. |
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Title |
Peculiarities of the orbital effect in the Fulde-Ferrell-Larkin-Ovchinnikov state in quasi-one-dimensional superconductors |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
89 |
Issue |
22 |
Pages |
224506 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Using the quasiclassical formalism, we determine the low-temperature phase diagram of a quasi-one-dimensional superconductor, taking into account the interchain Josephson coupling and the paramagnetic spin splitting. We show that the anisotropy of the onset of superconductivity changes in the FFLO state as compared with the conventional superconducting phase. It can result in anomalous peaks in the field-direction dependence of the upper critical field when the magnetic field length equals to the FFLO period. This regime is characterized by the lock-in effect of the FFLO modulation wave vector, which is governed by the magnetic length. Furthermore, in the FFLO phase, the anisotropy of the upper critical field is inverted at T-1(**) = 0.5T(c0), where the orbital anisotropy disappears. We suggest that an experimental study of the anisotropy of the upper critical field can provide very reach information about the parameters of the FFLO phase in quasi-1D samples. |
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Wos |
000336975000005 |
Publication Date |
2014-06-09 |
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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 |
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Open Access |
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Notes |
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Approved |
Most recent IF: 3.836; 2014 IF: 3.736 |
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Call Number |
UA @ lucian @ c:irua:117749 |
Serial |
2569 |
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Permanent link to this record |
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Author |
Gou, H.; Tsirlin, A.A.; Bykova, E.; Abakumov, A.M.; Van Tendeloo, G.; Richter, A.; Ovsyannikov, S.V.; Kurnosov, A.V.; Trots, D.M.; Konôpková, Z.; Liermann, H.P.; Dubrovinsky, L.; Dubrovinskaia, N.; |
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Title |
Peierls distortion, magnetism, and high hardness of manganese tetraboride |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
89 |
Issue |
6 |
Pages |
064108-64109 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
We report crystal structure, electronic structure, and magnetism of manganese tetraboride, MnB4, synthesized under high-pressure, high-temperature conditions. In contrast to superconducting FeB4 and metallic CrB4, which are both orthorhombic, MnB4 features a monoclinic crystal structure. Its lower symmetry originates from a Peierls distortion of the Mn chains. This distortion nearly opens the gap at the Fermi level, but despite the strong dimerization and the proximity of MnB4 to the insulating state, we find indications for a sizable paramagnetic effective moment of about 1.7 mu(B)/f.u., ferromagnetic spin correlations, and, even more surprisingly, a prominent electronic contribution to the specific heat. However, no magnetic order has been observed in standard thermodynamic measurements down to 2 K. Altogether, this renders MnB4 a structurally simple but microscopically enigmatic material; we argue that its properties may be influenced by electronic correlations. |
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Wos |
000332405000002 |
Publication Date |
2014-02-24 |
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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 |
39 |
Open Access |
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Notes |
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Approved |
Most recent IF: 3.836; 2014 IF: 3.736 |
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Call Number |
UA @ lucian @ c:irua:115819 |
Serial |
2571 |
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Permanent link to this record |
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Author |
Tsirlin, A.A.; Nath, R.; Abakumov, A.M.; Furukawa, Y.; Johnston, D.C.; Hemmida, M.; Krug von Nidda, H.-A.; Loidl, A.; Geibel, C.; Rosner, H. |
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Title |
Phase separation and frustrated square lattice magnetism of Na1.5VOPO4F0.5 |
Type |
A1 Journal article |
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Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
84 |
Issue |
1 |
Pages |
014429-014429,16 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Crystal structure, electronic structure, and magnetic behavior of the spin-1/2 quantum magnet Na1.5VOPO4F0.5 are reported. The disorder of Na atoms leads to a sequence of structural phase transitions revealed by synchrotron x-ray powder diffraction and electron diffraction. The high-temperature second-order α↔β transition at 500 K is of the order-disorder type, whereas the low-temperature β↔γ+γ′ transition around 250 K is of the first order and leads to a phase separation toward the polymorphs with long-range (γ) and short-range (γ′) order of Na. Despite the complex structural changes, the magnetic behavior of Na1.5VOPO4F0.5 probed by magnetic susceptibility, heat capacity, and electron spin resonance measurements is well described by the regular frustrated square lattice model of the high-temperature α-polymorph. The averaged nearest-neighbor and next-nearest-neighbor couplings are J̅ 1≃−3.7 K and J̅ 2≃6.6 K, respectively. Nuclear magnetic resonance further reveals the long-range ordering at TN=2.6 K in low magnetic fields. Although the experimental data are consistent with the simplified square-lattice description, band structure calculations suggest that the ordering of Na atoms introduces a large number of inequivalent exchange couplings that split the square lattice into plaquettes. Additionally, the direct connection between the vanadium polyhedra induces an unusually strong interlayer coupling having effect on the transition entropy and the transition anomaly in the specific heat. Peculiar features of the low-temperature crystal structure and the relation to isostructural materials suggest Na1.5VOPO4F0.5 as a parent compound for the experimental study of tetramerized square lattices as well as frustrated square lattices with different values of spin. |
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Wos |
000293247400008 |
Publication Date |
2011-07-28 |
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Series Editor |
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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 |
47 |
Open Access |
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Notes |
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Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
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Call Number |
UA @ lucian @ c:irua:91770 |
Serial |
2588 |
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Permanent link to this record |
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Author |
Wang, Z.-H.; Kronmüller, H.; Lebedev, O.I.; Gross, G.M.; Razavi, F.S.; Habermeier, H.U.; Shen, B.G. |
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Title |
Phase transition and magnetic anisotropy of (La,Sr)MnO3 thin films |
Type |
A1 Journal article |
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Year |
2002 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
65 |
Issue |
5 |
Pages |
054411-54416 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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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. |
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Wos |
000173647000058 |
Publication Date |
2002-07-27 |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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ISSN |
0163-1829;1095-3795; |
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 |
23 |
Open Access |
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Notes |
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Approved |
Most recent IF: 3.836; 2002 IF: NA |
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Call Number |
UA @ lucian @ c:irua:103883 |
Serial |
2592 |
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Author |
Nikolaev, A.V.; Prassides, K.; Michel, K.H. |
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Title |
Phase transitions in AC60 (A=Rb, Cs) fullerides |
Type |
A3 Journal article |
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Year |
1997 |
Publication |
Recent advances in the chemistry and physics of fullerenes and related materials |
Abbreviated Journal |
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Volume |
5 |
Issue |
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Pages |
450-460 |
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Keywords |
A3 Journal article; Condensed Matter Theory (CMT) |
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Wos |
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Publication Date |
0000-00-00 |
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Series Issue |
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Edition |
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ISBN |
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Additional Links |
UA library record |
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Impact Factor |
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Times cited |
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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:21182 |
Serial |
2596 |
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Permanent link to this record |
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Author |
Michel, K.H.; Verberck, B. |
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Title |
Phonon dispersions and piezoelectricity in bulk and multilayers of hexagonal boron nitride |
Type |
A1 Journal article |
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Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
83 |
Issue |
11 |
Pages |
115328-115328,14 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
A unified theory of phonon dispersions and piezoelectricity in bulk and multilayers of hexagonal boron nitride (h-BN) is derived. The dynamical matrix is calculated on the basis of an empirical force constant model of intralayer valence and interlayer van der Waals interactions. Coulomb interactions are calculated by Ewalds method, adapted for the three-dimensional (3D) and the multilayer case. The deformation of the ionic charge distribution with long-wave lattice displacements is taken into account. Special attention is devoted to the nonanalytic long-range Coulomb contribution to the dynamical matrix which is different for the 3D crystal and the multilayer case. Consequently there is a splitting of the transverse optical (TO) and longitudinal optical (LO) phonon branches of E1u symmetry and a discontinuity of the A2u branch at the Γ point in 3D h-BN. No such splitting and discontinuity at Γ are present in multilayer crystals with a finite number N of layers. There a diverging bundle of N overbending optical phonon branches emerges from Γ. Borns long-wave theory is applied and extended for the study of piezoelectricity in layered crystals. While 3D h-BN and h-BN multilayers with an even number of layers (symmetry D6h) are not piezoelectric, multilayers with an uneven number of Nu layers (symmetry D3h) are piezoelectric; the piezoelectric coefficient e1,11 is inversely proportional to Nu. |
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Wos |
000288783700005 |
Publication Date |
2011-03-24 |
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Series Editor |
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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 |
82 |
Open Access |
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Notes |
; Discussions with G. Heger, B. Partoens, and F. M. Peeters are gratefully acknowledged. This work has been supported by the Flemish Science Foundation (FWO-V1) and the Bijzonder Onderzoeksfonds, Universiteit Antwerpen (BOF-UA). ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
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Call Number |
UA @ lucian @ c:irua:89602 |
Serial |
2603 |
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Permanent link to this record |
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Author |
Axt, V.M.; Kuhn, T.; Vagov, A.; Peeters, F.M. |
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Title |
Phonon-induced pure dephasing in exciton-biexciton quantum dot systems driven by ultrafast laser pulse sequences |
Type |
A1 Journal article |
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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 |
125309-125315 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
A semiconductor quantum dot model accounting for single exciton as well as biexciton states coupled to phonons and laser light is investigated in the limit of strong electronic confinement. For an arbitrary sequence of excitations with ultrafast pulses analytical solutions are obtained for all density-matrix elements. The results are nonperturbative with respect to both the carrier-phonon and the carrier-light coupling. Numerical results for a single pulse excitation are presented illustrating spectral features of our solution as well as pulse area and temperature dependences. |
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Wos |
000232229400075 |
Publication Date |
2005-09-08 |
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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 |
48 |
Open Access |
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Notes |
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Approved |
Most recent IF: 3.836; 2005 IF: 3.185 |
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Call Number |
UA @ lucian @ c:irua:103139 |
Serial |
2604 |
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Permanent link to this record |