| Records |
| Author |
Horzum, S.; Sahin, H.; Cahangirov, S.; Cudazzo, P.; Rubio, A.; Serin, T.; Peeters, F.M. |
| Title |
Phonon softening and direct to indirect band gap crossover in strained single-layer MoSe2 |
Type |
A1 Journal article |
| Year |
2013 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
87 |
Issue |
12 |
Pages |
125415-5 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Motivated by recent experimental observations of Tongay et al. [Nano Lett. 12, 5576 (2012)] we show how the electronic properties and Raman characteristics of single layer MoSe2 are affected by elastic biaxial strain. We found that with increasing strain: (1) the E' and E '' Raman peaks (E-2g and E-1g in bulk) exhibit significant redshifts (up to similar to 30 cm(-1)), (2) the position of the A'(1) peak remains at similar to 180 cm(-1) (A(1g) in bulk) and does not change considerably with further strain, (3) the dispersion of low energy flexural phonons crosses over from quadratic to linear, and (4) the electronic band structure undergoes a direct to indirect band gap crossover under similar to 3% biaxial tensile strain. Thus the application of strain appears to be a promising approach for a rapid and reversible tuning of the electronic, vibrational, and optical properties of single layer MoSe2 and similar MX2 dichalcogenides. DOI:10.1103/PhysRevB.87.125415 |
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Thesis |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000316383700006 |
Publication Date |
2013-03-14 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1098-0121;1550-235X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
171 |
Open Access |
|
| Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem programme of the Flemish government. Computational resources were partially provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). H.S. is supported by a FWO Pegasus Marie Curie Long Fellowship. ; |
Approved |
Most recent IF: 3.836; 2013 IF: 3.664 |
Call Number  |
UA @ lucian @ c:irua:108277 |
Serial |
2605 |
| Permanent link to this record |
| |
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| |
| Author |
Abakumov, A.M.; Batuk, D.; Tsirlin, A.A.; Prescher, C.; Dubrovinsky, L.; Sheptyakov, D.V.; Schnelle, W.; Hadermann, J.; Van Tendeloo, G. |
| Title |
Frustrated pentagonal Cairo lattice in the non-collinear antiferromagnet Bi4Fe5O13F |
Type |
A1 Journal article |
| Year |
2013 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
87 |
Issue |
2 |
Pages |
024423-24429 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
We report on the crystal structure and magnetism of the iron-based oxyfluoride Bi4Fe5O13F, a material prototype of the Cairo pentagonal spin lattice. The crystal structure of Bi4Fe5O13F is determined by a combination of neutron diffraction, synchrotron x-ray diffraction, and transmission electron microscopy. It comprises layers of FeO6 octahedra and FeO4 tetrahedra forming deformed pentagonal units. The topology of these layers resembles a pentagonal least-perimeter tiling, which is known as the Cairo lattice. This topology gives rise to frustrated exchange couplings and underlies a sequence of magnetic transitions at T-1 = 62 K, T-2 = 71 K, and T-N = 178 K, as determined by thermodynamic measurements and neutron diffraction. Below T-1, Bi4Fe5O13F forms a fully ordered non-collinear antiferromagnetic structure, whereas the magnetic state between T-1 and T-N may be partially disordered according to the sizable increase in the magnetic entropy at T-1 and T-2. Bi4Fe5O13F reveals unanticipated magnetic transitions on the pentagonal Cairo spin lattice and calls for a further work on finite-temperature properties of this strongly frustrated spin model. DOI: 10.1103/PhysRevB.87.024423 |
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Thesis |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000314224800002 |
Publication Date |
2013-02-01 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
17 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.836; 2013 IF: 3.664 |
| Call Number |
UA @ lucian @ c:irua:107688 |
Serial |
1293 |
| Permanent link to this record |
| |
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| |
| Author |
Zhu, J.-J.; Badalyan, S.M.; Peeters, F.M. |
| Title |
Plasmonic excitations in Coulomb-coupled N-layer graphene structures |
Type |
A1 Journal article |
| Year |
2013 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
87 |
Issue |
8 |
Pages |
085401-85408 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We study Dirac plasmons and their damping in spatially separated N-layer graphene structures at finite doping and temperatures. The plasmon spectrum consists of one optical excitation with square-root dispersion and N – 1 acoustical excitations with linear dispersion, which are undamped at zero temperature and finite doping within a triangular energy region outside the electron-hole continuum. In the long-wavelength limit the energy and weight of the optical plasmon modes increase, respectively, as the square root and linearly with N in agreement with recent experimental findings. The energy and weight of the upper-lying acoustical branches also increase with N. This increase is strongest for the uppermost acoustical mode, and we find that its energy can exceed at some value of momentum the plasmon energy in an individual graphene sheet. Meanwhile, the energy of the low-lying acoustical branches decreases weakly with N as compared with the single acoustical mode in double-layer graphene structures. Our numerical calculations provide a detailed understanding of the overall behavior of the wave-vector dependence of the optical and acoustical multilayer plasmon modes and show how their dispersion and damping are modified as a function of temperature, interlayer spacing, and inlayer carrier density in (un)balanced graphene multilayer structures. DOI: 10.1103/PhysRevB.87.085401 |
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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 |
000314682900005 |
Publication Date |
2013-02-05 |
| 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 |
59 |
Open Access |
|
| Notes |
; This work was supported by the ESF-Eurocores program EuroGRAPHENE (CONGRAN project) and the Flemish Science Foundation (FWO-Vl). ; |
Approved |
Most recent IF: 3.836; 2013 IF: 3.664 |
| Call Number |
UA @ lucian @ c:irua:107671 |
Serial |
2645 |
| Permanent link to this record |
| |
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| |
| Author |
Li, B.; Djotyan, A.P.; Hao, Y.L.; Avetisyan, A.A.; Peeters, F.M. |
| Title |
Effect of a perpendicular magnetic field on the shallow donor states near a semiconductor-metal interface |
Type |
A1 Journal article |
| Year |
2013 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
87 |
Issue |
7 |
Pages |
075313-75319 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We investigate the influence of an external perpendicular magnetic field on the lowest-energy states of an electron bound to a donor which is located near a semiconductor-metal interface. The problem is treated within the effective mass approach and the lowest-energy states are obtained through (1) the “numerically exact” finite element method, and (2) a variational approach using a trial wave function where all image charges that emerge due to the presence of the metallic gate are taken into account. The trial wave functions are constructed such that they reduce to an exponential behavior for sufficiently small magnetic fields and become Gaussian for intermediate and large magnetic fields. The average electron-donor distance can be controlled by the external magnetic field. We find that the size of the 2p(z) state depends strongly on the magnetic field when the donor is close to the interface, showing a nonmonotonic behavior, in contrast with the ground and the other excited states. DOI: 10.1103/PhysRevB.87.075313 |
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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 |
000314874800017 |
Publication Date |
2013-02-13 |
| 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 |
1 |
Open Access |
|
| Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl). ; |
Approved |
Most recent IF: 3.836; 2013 IF: 3.664 |
| Call Number |
UA @ lucian @ c:irua:107664 |
Serial |
793 |
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| |
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| |
| Author |
Sahin, H.; Peeters, F.M. |
| Title |
Adsorption of alkali, alkaline-earth, and 3d transition metal atoms on silicene |
Type |
A1 Journal article |
| Year |
2013 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
87 |
Issue |
8 |
Pages |
085423-85429 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The adsorption characteristics of alkali, alkaline-earth, and transition metal adatoms on silicene, a graphene-like monolayer structure of silicon are analyzed by means of first-principles calculations. In contrast to graphene, interaction between the metal atoms and the silicene surface is quite strong due to its highly reactive buckled hexagonal structure. In addition to structural properties, we also calculate the electronic band dispersion, net magnetic moment, charge transfer, work function, and dipole moment of the metal adsorbed silicene sheets. Alkali metals, Li, Na, and K, adsorb to hollow sites without any lattice distortion. As a consequence of the significant charge transfer from alkalis to silicene, metalization of silicene takes place. Trends directly related to atomic size, adsorption height, work function, and dipole moment of the silicene/alkali adatom system are also revealed. We found that the adsorption of alkaline-earth metals on silicene is entirely different from their adsorption on graphene. The adsorption of Be, Mg, and Ca turns silicene into a narrow gap semiconductor. Adsorption characteristics of eight transition metals Ti, V, Cr, Mn, Fe, Co, Mo, and W are also investigated. As a result of their partially occupied d orbital, transition metals show diverse structural, electronic, and magnetic properties. Upon the adsorption of transition metals, depending on the adatom type and atomic radius, the system can exhibit metal, half-metal, and semiconducting behavior. For all metal adsorbates, the direction of the charge transfer is from adsorbate to silicene, because of its high surface reactivity. Our results indicate that the reactive crystal structure of silicene provides a rich playground for functionalization at nanoscale. DOI: 10.1103/PhysRevB.87.085423 |
| Address |
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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 |
000315146500008 |
Publication Date |
2013-02-19 |
| 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 |
281 |
Open Access |
|
| Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl). Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). H.S. is supported by a FWO Pegasus Marie Curie Fellowship. ; |
Approved |
Most recent IF: 3.836; 2013 IF: 3.664 |
| Call Number |
UA @ lucian @ c:irua:107663 |
Serial |
62 |
| Permanent link to this record |
| |
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| |
| Author |
Grujić, M.; Tadić, M.; Peeters, F.M. |
| Title |
Antiferromagnetism in hexagonal graphene structures : rings versus dots |
Type |
A1 Journal article |
| Year |
2013 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
87 |
Issue |
8 |
Pages |
085434-85436 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Themean-field Hubbard model is used to investigate the formation of the antiferromagnetic phase in hexagonal graphene rings with inner zigzag edges. The outer edge of the ring was taken to be either zigzag or armchair, and we found that both types of structures can have a larger antiferromagnetic interaction as compared with hexagonal dots. This difference could be partially ascribed to the larger number of zigzag edges per unit area in rings than in dots. Furthermore, edge states localized on the inner ring edge are found to hybridize differently than the edge states of dots, which results in important differences in the magnetism of graphene rings and dots. The largest staggered magnetization is found when the outer edge has a zigzag shape. However, narrow rings with armchair outer edge are found to have larger staggered magnetization than zigzag hexagons. The edge defects are shown to have the least effect on magnetization when the outer ring edge is armchair shaped. DOI: 10.1103/PhysRevB.87.085434 |
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Thesis |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000315146600005 |
Publication Date |
2013-02-20 |
| 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 |
29 |
Open Access |
|
| Notes |
; This work was supported by the EuroGRAPHENE programme of the ESF (project CONGRAN), the Serbian Ministry of Education, Science, and Technological Development, and the Flemish Science Foundation (FWO-VI). ; |
Approved |
Most recent IF: 3.836; 2013 IF: 3.664 |
| Call Number |
UA @ lucian @ c:irua:107661 |
Serial |
137 |
| Permanent link to this record |
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| |
| Author |
Arsoski, V.V.; Tadić, M.Z.; Peeters, F.M. |
| Title |
Strain and band-mixing effects on the excitonic Aharonov-Bohm effect in In(Ga)As/GaAs ringlike quantum dots |
Type |
A1 Journal article |
| Year |
2013 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
87 |
Issue |
8 |
Pages |
085314-14 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Neutral excitons in strained axially symmetric In(Ga)As/GaAs quantum dots with a ringlike shape are investigated. Similar to experimental self-assembled quantum rings, the analyzed quantum dots have volcano-like shapes. The continuum mechanical model is employed to determine the strain distribution, and the single-band envelope function approach is adopted to compute the electron states. The hole states are determined by the axially symmetric multiband Luttinger-Kohn Hamiltonian, and the exciton states are obtained from an exact diagonalization. We found that the presence of the inner layer covering the ring opening enhances the excitonic Aharonov-Bohm (AB) oscillations. The reason is that the hole becomes mainly localized in the inner part of the quantum dot due to strain, whereas the electron resides mainly inside the ring-shaped rim. Interestingly, larger AB oscillations are found in the analyzed quantum dot than in a fully opened quantum ring of the same width. Comparison with the unstrained ringlike quantum dot shows that the amplitude of the excitonic Aharonov-Bohm oscillations are almost doubled in the presence of strain. The computed oscillations of the exciton energy levels are comparable in magnitude to the oscillations measured in recent experiments. DOI: 10.1103/PhysRevB.87.085314 |
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Thesis |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000315278000003 |
Publication Date |
2013-02-25 |
| 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 |
18 |
Open Access |
|
| Notes |
; This work was supported by the EU NoE: SANDiE, the Ministry of Education, Science, and Technological Development of Serbia, and the Flemish Science Foundation (FWO-Vl). ; |
Approved |
Most recent IF: 3.836; 2013 IF: 3.664 |
| Call Number |
UA @ lucian @ c:irua:107656 |
Serial |
3165 |
| Permanent link to this record |
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| |
| Author |
Zhang, S.H.; Xu, W.; Badalyan, S.M.; Peeters, F.M. |
| Title |
Piezoelectric surface acoustical phonon limited mobility of electrons in graphene on a GaAs substrate |
Type |
A1 Journal article |
| Year |
2013 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
87 |
Issue |
7 |
Pages |
075443-75445 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We study the mobility of Dirac fermions in monolayer graphene on a GaAs substrate, limited by the combined action of the extrinsic potential of piezoelectric surface acoustical phonons of GaAs (PA) and of the intrinsic deformation potential of acoustical phonons in graphene (DA). In the high-temperature (T) regime, the momentum relaxation rate exhibits the same linear dependence on T but different dependencies on the carrier density n, corresponding to the mobility mu proportional to 1 root n and 1/n, respectively for the PA and DA scattering mechanisms. In the low-T Bloch-Gruneisen regime, the mobility shows the same square-root density dependence mu proportional to root n, but different temperature dependencies mu proportional to T-3 and T-4, respectively for PA and DA phonon scattering. DOI: 10.1103/PhysRevB.87.075443 |
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Thesis |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000315375200008 |
Publication Date |
2013-02-27 |
| 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 |
25 |
Open Access |
|
| Notes |
; This work was supported by the ESF-Eurocores program EuroGRAPHENE (CONGRAN project) and the Flemish Science Foundation (FWO-VI). ; |
Approved |
Most recent IF: 3.836; 2013 IF: 3.664 |
| Call Number |
UA @ lucian @ c:irua:107655 |
Serial |
2622 |
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| |
| Author |
Neek-Amal, M.; Beheshtian, J.; Shayeganfar, F.; Singh, S.K.; Los, J.H.; Peeters, F.M. |
| Title |
Spiral graphone and one-sided fluorographene nanoribbons |
Type |
A1 Journal article |
| Year |
2013 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
87 |
Issue |
7 |
Pages |
075448-8 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The instability of a free-standing one-sided hydrogenated/fluorinated graphene nanoribbon, i.e., graphone/fluorographene, is studied using ab initio, semiempirical, and large-scale molecular dynamics simulations. Free-standing semi-infinite armchairlike hydrogenated/fluorinated graphene (AC-GH/AC-GF) and boatlike hydrogenated/fluorinated graphene (B-GH/B-GF) (nanoribbons which are periodic along the zigzag direction) are unstable and spontaneously transform into spiral structures. We find that rolled, spiral B-GH and B-GF are energetically more favorable than spiral AC-GH and AC-GF which is opposite to the double-sided flat hydrogenated/fluorinated graphene, i.e., graphane/fluorographene. We found that the packed, spiral structures exhibit an unexpected localized highest occupied molecular orbital and lowest occupied molecular orbital at the edges with increasing energy gap during rolling. These rolled hydrocarbon structures are stable beyond room temperature up to at least T = 1000 K within our simulation time of 1 ns. DOI: 10.1103/PhysRevB.87.075448 |
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Thesis |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000315481800005 |
Publication Date |
2013-02-27 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1098-0121;1550-235X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
14 |
Open Access |
|
| Notes |
; We thank A. Sadeghi, M. R. Ejtehadi, and J. Amini for their useful comments. This work is supported by the ESF EuroGRAPHENE project CONGRAN and the Flemish Science Foundation (FWO-Vl). M.N.-A. is supported by a EU-Marie Curie IIF fellowship program Grant No. 299855. ; |
Approved |
Most recent IF: 3.836; 2013 IF: 3.664 |
| Call Number |
UA @ lucian @ c:irua:107654 |
Serial |
3106 |
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| Author |
Ding, J.F.; Lebedev, O.I.; Turner, S.; Tian, Y.F.; Hu, W.J.; Seo, J.W.; Panagopoulos, C.; Prellier, W.; Van Tendeloo, G.; Wu, T. |
| Title |
Interfacial spin glass state and exchange bias in manganite bilayers with competing magnetic orders |
Type |
A1 Journal article |
| Year |
2013 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
87 |
Issue |
5 |
Pages |
054428-7 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
The magnetic properties of manganite bilayers composed of G-type antiferromagnetic (AFM) SrMnO3 and double-exchange ferromagnetic (FM) La0.7Sr0.3MnO3 are studied. A spin-glass state is observed as a result of competing magnetic orders and spin frustration at the La0.7Sr0.3MnO3/SrMnO3 interface. The dependence of the irreversible temperature on the cooling magnetic field follows the Almeida-Thouless line. Although an ideal G-type AFM SrMnO3 is featured with a compensated spin configuration, the bilayers exhibit exchange bias below the spin glass freezing temperature, which is much lower than the Néel temperature of SMO, indicating that the exchange bias is strongly correlated with the spin glass state. The results indicate that the spin frustration that originates from the competition between the AFM super-exchange and the FM double-exchange interactions can induce a strong magnetic anisotropy at the La0.7Sr0.3MnO3/SrMnO3 interface. |
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Thesis |
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Place of Publication |
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Editor |
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Wos |
000315271200002 |
Publication Date |
2013-02-22 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1098-0121;1550-235X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
98 |
Open Access |
|
| Notes |
FWO; COUNTATOMS; Hercules |
Approved |
Most recent IF: 3.836; 2013 IF: 3.664 |
| Call Number |
UA @ lucian @ c:irua:107349 |
Serial |
1696 |
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| Author |
Saniz, R.; Partoens, B.; Peeters, F.M. |
| Title |
Confinement effects on electron and phonon degrees of freedom in nanofilm superconductors : a Green function approach |
Type |
A1 Journal article |
| Year |
2013 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
87 |
Issue |
6 |
Pages |
064510-64513 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The Green function approach to the Bardeen-Cooper-Schrieffer theory of superconductivity is used to study nanofilms. We go beyond previous models and include effects of confinement on the strength of the electron-phonon coupling as well as on the electronic spectrum and on the phonon modes. Within our approach, we find that in ultrathin films, confinement effects on the electronic screening become very important. Indeed, contrary to what has been advanced in recent years, the sudden increases of the density of states when new bands start to be occupied as the film thickness increases, tend to suppress the critical temperature rather than to enhance it. On the other hand, the increase of the number of phonon modes with increasing number of monolayers in the film leads to an increase in the critical temperature. As a consequence, the superconducting critical parameters in such nanofilms are determined by these two competing effects. Furthermore, in sufficiently thin films, the condensate consists of well-defined subcondensates associated with the occupied bands, each with a distinct coherence length. The subcondensates can interfere constructively or destructively giving rise to an interference pattern in the Cooper pair probability density. |
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Place of Publication |
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Editor |
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Wos |
000315374100009 |
Publication Date |
2013-02-25 |
| Series Editor |
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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). R.S. thanks M. R. Norman, B. Soree, and L. Komendova for useful comments. ; |
Approved |
Most recent IF: 3.836; 2013 IF: 3.664 |
| Call Number |
UA @ lucian @ c:irua:107072 |
Serial |
487 |
| Permanent link to this record |
| |
|
| |
| Author |
Sivek, J.; Sahin, H.; Partoens, B.; Peeters, F.M. |
| Title |
Adsorption and absorption of boron, nitrogen, aluminum, and phosphorus on silicene : stability and electronic and phonon properties |
Type |
A1 Journal article |
| Year |
2013 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
87 |
Issue |
8 |
Pages |
085444-85448 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Ab initio calculations within the density-functional theory formalism are performed to investigate the chemical functionalization of a graphene-like monolayer of siliconsilicenewith B, N, Al, or P atoms. The structural, electronic, magnetic, and vibrational properties are reported. The most preferable adsorption sites are found to be valley, bridge, valley and hill sites for B, N, Al, and P adatoms, respectively. All the relaxed systems with adsorbed/substituted atoms exhibit metallic behavior with strongly bonded B, N, Al, and P atoms accompanied by an appreciable electron transfer from silicene to the B, N, and P adatom/substituent. The Al atoms exhibit opposite charge transfer, with n-type doping of silicene and weaker bonding. The adatoms/substituents induce characteristic branches in the phonon spectrum of silicene, which can be probed by Raman measurements. Using molecular dynamics, we found that the systems under study are stable up to at least T=500 K. Our results demonstrate that silicene has a very reactive and functionalizable surface. |
| 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 |
|
| Language |
|
Wos |
000315482900007 |
Publication Date |
2013-02-27 |
| 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 |
169 |
Open Access |
|
| Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem foundation of the Flemish government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure), and HPC infrastructure of the University of Antwerp (CalcUA) a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation. H.S. is supported by a FWO Pegasus Marie Curie Fellowship. ; |
Approved |
Most recent IF: 3.836; 2013 IF: 3.664 |
| Call Number |
UA @ lucian @ c:irua:107071 |
Serial |
60 |
| Permanent link to this record |
| |
|
| |
| Author |
Turner, S.; Lebedev, O.I.; Verbeeck, J.; Gehrke, K.; Moshnyaga, V.; Van Tendeloo, G. |
| Title |
Structural phase transition and spontaneous interface reconstruction in La2/3Ca1/3MnO3/BaTiO3 superlattices |
Type |
A1 Journal article |
| Year |
2013 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
87 |
Issue |
3 |
Pages |
035418-8 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
(La2/3Ca1/3MnO3)n/(BaTiO3)m (LCMOn/BTOm) superlattices on MgO and SrTiO3 substrates with different layer thicknesses (n = 10, 38, 40 and m = 5, 18, 20) have been grown by metal organic aerosol deposition (MAD) and have been fully characterized down to the atomic scale to study the interface characteristics. Scanning transmission electron microscopy combined with spatially resolved electron energy-loss spectroscopy provides clear evidence for the existence of atomically sharp interfaces in MAD grown films, which exhibit epitaxial growth conditions, a uniform normal strain, and a fully oxidized state. Below a critical layer thickness the LCMO structure is found to change from the bulk Pnma symmetry to a pseudocubic R3̅ c symmetry. An atomically flat interface reconstruction consisting of a single Ca-rich atomic layer is observed on the compressively strained BTO on LCMO interface, which is thought to partially neutralize the total charge from the alternating polar atomic layers in LCMO as well as relieving strain at the interface. No interface reconstruction is observed at the tensile strained LCMO on BTO interface. |
| 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 |
000313940400008 |
Publication Date |
2013-01-23 |
| 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 |
12 |
Open Access |
|
| Notes |
FWO; Hercules; Countatoms |
Approved |
Most recent IF: 3.836; 2013 IF: 3.664 |
| Call Number |
UA @ lucian @ c:irua:106180 |
Serial |
3245 |
| Permanent link to this record |
| |
|
| |
| Author |
Berdiyorov, G.R.; Chao, X.H.; Peeters, F.M.; Wang, H.B.; Moshchalkov, V.V.; Zhu, B.Y. |
| Title |
Magnetoresistance oscillations in superconducting strips : a Ginzburg-Landau study |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
86 |
Issue |
22 |
Pages |
224504-224508 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Within the time-dependent Ginzburg-Landau theory we study the dynamic properties of current-carrying superconducting strips in the presence of a perpendicular magnetic field. We found pronounced voltage peaks as a function of the magnetic field, the amplitude of which depends both on sample dimensions and external parameters. These voltage oscillations are a consequence of moving vortices, which undergo alternating static and dynamic phases. At higher fields or for high currents, the continuous motion of vortices is responsible for the monotonic background on which the resistance oscillations due to the entry of additional vortices are superimposed. Mechanisms for such vortex-assisted resistance oscillations are discussed. Qualitative changes in the magnetoresistance curves are observed in the presence of random defects, which affect the dynamics of vortices in the system. |
| 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 |
|
Wos |
000312064300004 |
Publication Date |
2012-12-10 |
| 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 |
31 |
Open Access |
|
| Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl) and the ESF-NES program. G. R. B. acknowledges support from FWO-Vl. B.Y.Z. acknowledges the support from the MOST 973 Projects No. 2011CBA00110 and No. 2009CB930803, and the National Natural Science Foundation of China. V. V. M. acknowledges support from the Methusalem Funding by the Flemish Government. ; |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
| Call Number |
UA @ lucian @ c:irua:105969 |
Serial |
1930 |
| Permanent link to this record |
| |
|
| |
| Author |
Geurts, R.; Milošević, M.V.; Albino Aguiar, J.; Peeters, F.M. |
| Title |
Enhanced stability of vortex-antivortex states in two-component mesoscopic superconductors |
Type |
A1 Journal article |
| Year |
2013 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
87 |
Issue |
2 |
Pages |
024501-24508 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Using the Ginzburg-Landau (GL) theory, we calculate the stability of sample symmetry-induced vortex-antivortex molecules in a mesoscopic superconducting bilayer exposed to a homogeneous magnetic field. We demonstrate the conditions under which the two condensates cooperatively broaden the field-temperature stability range of the composite (joint) vortex-antivortex state. In cases when such broadening is not achieved, a reentrance of the vortex-antivortex state is found at lower temperatures. In a large portion of the phase diagram noncomposite states are possible, in which the antivortex is present in only one of the layers. In this case, we demonstrate that the vortex-antivortex molecule in one of the layers can be pinned and enlarged by interaction with a vortex molecule in the other. Using analogies in the respective GL formalisms, we map our findings for the bilayer onto mesoscopic two-band superconductors. |
| 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 |
|
Wos |
000313029800003 |
Publication Date |
2013-01-04 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
25 |
Open Access |
|
| Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vlaanderen), the Brazilian science agencies FACEPE/CNPq under Grant No. APQ-0589-1.05/08 and CNPq under Grant No. 309832/2007-1, and the CNPq-FWO cooperation program under Grant No. 490681/2010-7. M.V.M. acknowledges support from the CAPES-PVE program. ; |
Approved |
Most recent IF: 3.836; 2013 IF: 3.664 |
| Call Number |
UA @ lucian @ c:irua:105925 |
Serial |
1058 |
| Permanent link to this record |
| |
|
| |
| Author |
Van Aert, S.; de Backer, A.; Martinez, G.T.; Goris, B.; Bals, S.; Van Tendeloo, G.; Rosenauer, A. |
| Title |
Procedure to count atoms with trustworthy single-atom sensitivity |
Type |
A1 Journal article |
| Year |
2013 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
87 |
Issue |
6 |
Pages |
064107-6 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
We report a method to reliably count the number of atoms from high-angle annular dark field scanning transmission electron microscopy images. A model-based analysis of the experimental images is used to measure scattering cross sections at the atomic level. The high sensitivity of these measurements in combination with a thorough statistical analysis enables us to count atoms with single-atom sensitivity. The validity of the results is confirmed by means of detailed image simulations. We will show that the method can be applied to nanocrystals of arbitrary shape, size, and atom type without the need for a priori knowledge about the atomic structure. |
| 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 |
000315144700006 |
Publication Date |
2013-02-20 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
106 |
Open Access |
|
| Notes |
FWO; 262348 ESMI; 312483 ESTEEM2;246791 COUNTATOMS; Hercules 3; esteem2_jra2 |
Approved |
Most recent IF: 3.836; 2013 IF: 3.664 |
| Call Number |
UA @ lucian @ c:irua:105674 |
Serial |
2718 |
| 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 |
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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 |
000287484800005 |
Publication Date |
2011-02-18 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
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 |
| |
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| |
| 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 |
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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 |
| Series Editor |
|
Series Title |
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Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
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 |
| |
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| |
| 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 |
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| Language |
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Wos |
000313100500010 |
Publication Date |
2012-12-12 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
|
| ISSN |
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 |
| |
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| |
| 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 |
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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 |
000310683600002 |
Publication Date |
2012-11-05 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
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 |
| |
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| |
| 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 |
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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 |
000310840400005 |
Publication Date |
2012-11-07 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
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Edition |
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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 |
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 |
| |
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| |
| 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 |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000311605000003 |
Publication Date |
2012-11-28 |
| Series Editor |
|
Series Title |
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Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
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 |
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| 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 |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
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 |
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| |
| 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 |
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| Language |
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Wos |
A1995TK97900042 |
Publication Date |
2002-07-27 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
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 |
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| 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 |
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| Language |
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Wos |
000074062600130 |
Publication Date |
2002-07-25 |
| 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 |
0921-4526; |
ISBN |
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Additional Links |
UA library record; WoS full record |
| Impact Factor |
1.386 |
Times cited |
|
Open Access |
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| 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 |
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| 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. |
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Thesis |
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Place of Publication |
London |
Editor |
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| Language |
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Wos |
000080687900002 |
Publication Date |
2007-07-08 |
| 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 |
0141-8610;1460-6992; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
|
Times cited |
3 |
Open Access |
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| Notes |
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Approved |
Most recent IF: NA |
| Call Number |
UA @ lucian @ c:irua:104297 |
Serial |
956 |
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| 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 |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000084631600039 |
Publication Date |
2002-07-27 |
| 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 |
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 |
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| 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 |
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Editor |
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| Language |
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Wos |
000176767900019 |
Publication Date |
2002-07-27 |
| 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 |
0163-1829;1095-3795; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
14 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.836; 2002 IF: NA |
| Call Number |
UA @ lucian @ c:irua:104154 |
Serial |
519 |
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| 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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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000177873000137 |
Publication Date |
2002-10-01 |
| 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 |
0163-1829;1095-3795; |
ISBN |
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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 |
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| 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 |
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Thesis |
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| Publisher |
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Place of Publication |
London |
Editor |
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| Language |
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Wos |
000178678400008 |
Publication Date |
2002-09-18 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0953-8984; |
ISBN |
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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 |
