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Records |
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Author |
Varykhalov, A.; Marchenko, D.; Sanchez-Barriga, J.; Scholz, M.R.; Verberck, B.; Trauzettel, B.; Wehling, T.O.; Carbone, C.; Rader, O. |
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Title |
Intact dirac cones at broken sublattice symmetry : photoemission study of graphene on Ni and Co |
Type |
A1 Journal article |
| |
Year |
2012 |
Publication |
Physical review X |
Abbreviated Journal |
Phys Rev X |
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| |
Volume |
2 |
Issue |
4 |
Pages |
041017-10 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The appearance of massless Dirac fermions in graphene requires two equivalent carbon sublattices of trigonal shape. While the generation of an effective mass and a band gap at the Dirac point remains an unresolved problem for freestanding extended graphene, it is well established by breaking translational symmetry by confinement and by breaking sublattice symmetry by interaction with a substrate. One of the strongest sublattice-symmetry-breaking interactions with predicted and measured band gaps ranging from 400 meV to more than 3 eV has been attributed to the interfaces of graphene with Ni and Co, which are also promising spin-filter interfaces. Here, we apply angle-resolved photoemission to epitaxial graphene on Ni (111) and Co(0001) to show the presence of intact Dirac cones 2.8 eV below the Fermi level. Our results challenge the common belief that the breaking of sublattice symmetry by a substrate and the opening of the band gap at the Dirac energy are in a straightforward relation. A simple effective model of a biased bilayer structure composed of graphene and a sublattice-symmetry-broken layer, corroborated by density-functional-theory calculations, demonstrates the general validity of our conclusions. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
College Park, Md |
Editor |
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Language |
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Wos |
000312703200001 |
Publication Date |
2012-12-22 |
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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 |
2160-3308; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
12.789 |
Times cited |
86 |
Open Access |
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Notes |
; A. V. acknowledges helpful discussions with N. Sandler. This work was supported by SPP 1459 of the Deutsche Forschungsgemeinschaft. B. V. acknowledges support from the Research Foundation Flanders (FWO-Vlaanderen). B. T. and T. O. W. would like to thank the KITP at Santa Barbara for hospitality during the completion of this work. ; |
Approved |
Most recent IF: 12.789; 2012 IF: 6.711 |
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Call Number  |
UA @ lucian @ c:irua:105964 |
Serial |
1677 |
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| Permanent link to this record |
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Author |
Berdiyorov, G.R.; Chao, X.H.; Peeters, F.M.; Wang, H.B.; Moshchalkov, V.V.; Zhu, B.Y. |
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| |
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 |
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| |
Volume |
86 |
Issue |
22 |
Pages |
224504-224508 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
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. |
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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 |
000312064300004 |
Publication Date |
2012-12-10 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
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 |
31 |
Open Access |
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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 |
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| |
Call Number |
UA @ lucian @ c:irua:105969 |
Serial |
1930 |
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| Permanent link to this record |
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Author |
Marikutsa, A.; Krivetskiy, V.; Yashina, L.; Rumyantseva, M.; Konstantinova, E.; Ponzoni, A.; Comini, E.; Abakumov, A.; Gaskov, A. |
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Title |
Catalytic impact of RuOx clusters to high ammonia sensitivity of tin dioxide |
Type |
A1 Journal article |
| |
Year |
2012 |
Publication |
Sensors and actuators : B : chemical
T2 – 25th Eurosensors Conference, SEP 04-07, 2011, Athens, GREECE |
Abbreviated Journal |
Sensor Actuat B-Chem |
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| |
Volume |
175 |
Issue |
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Pages |
186-193 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
A comparative study of NH3-sensing performance of blank and modified nanocrystal line SnO2 was performed. Tin dioxide modified by ruthenium displayed the highest ammonia sensitivity with a maximum signal at 200 degrees C. The modifier was shown by XPS and EPR to occur in a mixed valence state of oxidized ruthenium distributed between the surface and bulk of tin dioxide nanocrystals. RuOx clustering on SnO2 surface was detected by means of electron microscopy assisted EDX-mapping. The effect of RuOx on tin dioxide interaction with ammonia was studied by temperature-programmed NH3 desorption, simultaneous Kelvin probe and DC-resistance measurements, EPR spectroscopy and analyses of the gas-solid interaction products. The modifier was shown to promote the materials reactivity to NH3 due to the catalytic activity of RuOx. The interaction with ammonia resulted in dipoles formation on the oxide surface along with reducing the grains net surface charge, established from the electron affinity increase and resistance decrease during NH3 exposure. The RuOx-catalyzed gas-solid interaction was deduced to proceed deeper than in the case of non-modified SnO2 and to yield nitrogen oxides (e.g. NO2), as was suggested by the oxidative character of gaseous products of NH3 interaction with RuOx-modified tin dioxide at 200 degrees C. (C) 2012 Elsevier B.V. All rights reserved. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Lausanne |
Editor |
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Language |
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Wos |
000312358700033 |
Publication Date |
2012-06-19 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0925-4005; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.401 |
Times cited |
20 |
Open Access |
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Notes |
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Approved |
Most recent IF: 5.401; 2012 IF: 3.535 |
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Call Number |
UA @ lucian @ c:irua:105985 |
Serial |
293 |
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| Permanent link to this record |
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Author |
Van Duppen, B.; Peeters, F.M. |
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Title |
Comment on “Chiral tunneling in trilayer graphene” [Appl. Phys. Lett. 100, 163102 (2012)] |
Type |
Editorial |
| |
Year |
2012 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
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| |
Volume |
101 |
Issue |
22 |
Pages |
226101-1 |
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Keywords |
Editorial; Condensed Matter Theory (CMT) |
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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 |
Amer inst physics |
Place of Publication |
Melville |
Editor |
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Language |
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Wos |
000311967000107 |
Publication Date |
2012-11-29 |
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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 |
0003-6951; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.411 |
Times cited |
7 |
Open Access |
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Notes |
; ; |
Approved |
Most recent IF: 3.411; 2012 IF: 3.794 |
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Call Number |
UA @ lucian @ c:irua:105999 |
Serial |
408 |
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Author |
de Sousa, J.S.; Covaci, L.; Peeters, F.M.; Farias, G.A. |
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Title |
Time-dependent investigation of charge injection in a quantum dot containing one electron |
Type |
A1 Journal article |
| |
Year |
2012 |
Publication |
Journal of applied physics |
Abbreviated Journal |
J Appl Phys |
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Volume |
112 |
Issue |
9 |
Pages |
093705-93709 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The interaction of an injected electron towards a quantum dot (QD) containing a single confined electron is investigated using a flexible time-dependent quantum mechanics formalism, which allows both electrons to move and undergo quantum transitions. Different scenarios combining quantum dot dimensions, dielectric constant, injected wave packet energy, and width were explored, and our main results are: (i) due to the large characteristic transitions times between the confined state in the quantum dot and the delocalized state in the continuum, it is relatively difficult to ionize the occupied QD by Coulomb interaction solely and (ii) the charging state of the quantum dot can be sensed by direct injection of charges. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4759292] |
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Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000311968400052 |
Publication Date |
2012-11-06 |
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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 |
0021-8979; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.068 |
Times cited |
1 |
Open Access |
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Notes |
; This work was financially supported by the Brazilian National Research Council (CNPq), under Contract No. NanoBioEstruturas 555183/2005-0, Fundao Cearense de Apoio ao Desenvolvimento Cientfico e Tecnolgico (Funcap), CAPES, Pronex/CNPq/ Funcap, the Bilateral program between Flanders and Brazil, and the Flemish Science Foundation (FWO). ; |
Approved |
Most recent IF: 2.068; 2012 IF: 2.210 |
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Call Number |
UA @ lucian @ c:irua:106014 |
Serial |
3664 |
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Author |
Bending, S.J.; Neal, J.S.; Milošević, M.V.; Potenza, A.; san Emeterio, L.; Marrows, C.H. |
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Title |
Vortex-antivortex 'molecular crystals' in hybrid ferromagnet/superconductor structures |
Type |
A1 Journal article |
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Year |
2009 |
Publication |
Journal of physics : conference series |
Abbreviated Journal |
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Volume |
150 |
Issue |
5 |
Pages |
052019 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We have used high resolution Hall probe microscopy to image vortex-antivortex (V-AV) 'molecules' induced in superconducting Pb films by the stray fields from square arrays of ferromagnetic Co/Pt dots. We have directly observed spontaneous V-AV pairs and studied how they interact with added 'free' (anti)fluxons in an applied magnetic field. We observe a rich variety of subtle phenomena arising from competing symmetries in our system which can either drive added antivortices to join AV shells around nanomagnets or stabilise the translationally symmetric AV lattice between the dots. Added vortices annihilate AV shells, leading eventually to a stable 'nulling' state with no free fluxons, which should exhibit a strongly (field-)enhanced critical current. At higher densities we actually observe vortex shells around the magnets, stabilised by the asymmetric anti-pinning potential. Our experimental findings are in good agreement with Ginzburg-Landau calculations. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Bristol |
Editor |
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Language |
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Wos |
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Publication Date |
2009-04-01 |
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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 |
1742-6588;1742-6596; |
ISBN |
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Additional Links |
UA library record |
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Impact Factor |
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Times cited |
|
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:106136 |
Serial |
3855 |
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Author |
Connolly, M.R.; Milošević, M.V.; Bending, S.J.; Clem, J.R.; Tamegai, T. |
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Title |
Vortex 'puddles' and magic vortex numbers in mesoscopic superconducting disks |
Type |
A1 Journal article |
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Year |
2009 |
Publication |
Journal of physics : conference series |
Abbreviated Journal |
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Volume |
150 |
Issue |
5 |
Pages |
052039 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The magnetic properties of a superconducting disk change dramatically when its dimensions become mesoscopic. Unlike large disks, where the screening currents induced by an applied magnetic field are strong enough to force vortices to accumulate in a 'puddle' at the centre, in a mesoscopic disk the interaction between one of these vortices and the edge currents can be comparable to the intervortex repulsion, resulting in a destruction of the ordered triangular vortex lattice structure at the centre. Vortices instead form clusters which adopt polygonal and shell-like structures which exhibit magic number states similar to those of charged particles in a confining potential, and electrons in artificial atoms. We have fabricated mesoscopic high temperature superconducting Bi2Sr2CaCu2O8+δ disks and investigated their magnetic properties using magneto-optical imaging (MOI) and high resolution scanning Hall probe microscopy (SHPM). The temperature dependence of the vortex penetration field measured using MOI is in excellent agreement with models of the thermal excitation of pancake vortices over edge barriers. The growth of the central vortex puddle has been directly imaged using SHPM and magic vortex numbers showing higher stability have been correlated with abrupt jumps in the measured local magnetisation curves. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Bristol |
Editor |
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Language |
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Wos |
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Publication Date |
2009-04-01 |
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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 |
1742-6588;1742-6596; |
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:106137 |
Serial |
3881 |
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Author |
Engbarth, M.; Milošević, M.V.; Bending, S.J.; Nasirpouri, F. |
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Title |
Geometry-guided flux behaviour in superconducting Pb microcrystals |
Type |
A1 Journal article |
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Year |
2009 |
Publication |
Journal of physics : conference series |
Abbreviated Journal |
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Volume |
150 |
Issue |
5 |
Pages |
052048 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Electrochemistry offers highly flexible routes to fabrication of a wide variety of mesostructures, including three-dimensional (3D) crystallites, thin films and nanowires. Using this method we have grown various 3D superconducting Pb mesostructures with vastly different morphologies. We present here results on a truncated(half)-icosahedron with a hexagonal base and a tripod structure with a triangular base. Using Hall probe magnetometry we have obtained magnetisation curves for these structures at several temperatures and see evidence of geometry-driven flux entry and exit as well as flux trapping caused by specific sample geometries. We also observe behaviour that we interpret in terms of the formation of giant vortices, bearing in mind that bulk Pb is a type-I superconducting material. |
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Corporate Author |
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Publisher |
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Place of Publication |
Bristol |
Editor |
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Wos |
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Publication Date |
2009-04-01 |
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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 |
1742-6588;1742-6596; |
ISBN |
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Additional Links |
UA library record |
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Impact Factor |
|
Times cited |
1 |
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:106138 |
Serial |
1332 |
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Author |
Bending, S.J.; Milošević, M.V.; Moshchalkov, V.V. |
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Title |
Polarity-dependent vortex pinning and spontaneous vortex-antivortex structures in superconductor/ferromagnet hybrids |
Type |
H1 Book chapter |
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Year |
2010 |
Publication |
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Abbreviated Journal |
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Volume |
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Issue |
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Pages |
299-322 |
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Keywords |
H1 Book chapter; Condensed Matter Theory (CMT) |
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Abstract |
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Address |
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Publisher |
Springer |
Place of Publication |
Berlin |
Editor |
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Language |
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Wos |
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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 |
978-3-642-15136-1 |
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:106139 |
Serial |
2659 |
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Author |
Batuk, M.; Batuk, D.; Tsirlin, A.A.; Rozova, M.G.; Antipov, E.V.; Hadermann, J.; Van Tendeloo, G. |
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Title |
Homologous series of layered perovskites An+1BnO3n-1Cl : crystal and magnetic structure of a new oxychloride Pb4BiFe4O11Cl |
Type |
A1 Journal article |
| |
Year |
2013 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
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Volume |
52 |
Issue |
4 |
Pages |
2208-2218 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The nuclear and magnetic structure of a novel oxychloride Pb4BiFe4O11Cl has been studied over the temperature range 1.5700 K using a combination of transmission electron microscopy and synchrotron and neutron powder diffraction [space group P4/mbm, a = 5.5311(1) Å, c = 19.586(1) Å, T = 300 K]. Pb4BiFe4O11Cl is built of truncated (Pb,Bi)3Fe4O11 quadruple perovskite blocks separated by CsCl-type (Pb,Bi)2Cl slabs. The perovskite blocks consist of two layers of FeO6 octahedra located between two layers of FeO5 tetragonal pyramids. The FeO6 octahedra rotate about the c axis, resulting in a √2ap × √2ap × c superstructure. Below TN = 595(17) K, Pb4BiFe4O11Cl adopts a G-type antiferromagnetic structure with the iron magnetic moments confined to the ab plane. The ordered magnetic moments at 1.5 K are 3.93(3) and 3.62(4) μB on the octahedral and square-pyramidal iron sites, respectively. Pb4BiFe4O11Cl can be considered a member of the perovskite-based An+1BnO3n1Cl homologous series (A = Pb/Bi; B = Fe) with n = 4. The formation of a subsequent member of the series with n = 5 is also demonstrated. |
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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 |
Easton, Pa |
Editor |
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Language |
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Wos |
000315255200067 |
Publication Date |
2013-02-05 |
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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 |
0020-1669;1520-510X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
4.857 |
Times cited |
6 |
Open Access |
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Notes |
Countatoms |
Approved |
Most recent IF: 4.857; 2013 IF: 4.794 |
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| |
Call Number |
UA @ lucian @ c:irua:106185 |
Serial |
1486 |
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| Permanent link to this record |
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Author |
Verheyen, E.; Jo, C.; Kurttepeli, M.; Vanbutsele, G.; Gobechiya, E.; Korányi, T.I.; Bals, S.; Van Tendeloo, G.; Ryoo, R.; Kirschhock, C.E.A.; Martens, J.A.; |
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Title |
Molecular shape-selectivity of MFI zeolite nanosheets in n-decane isomerization and hydrocracking |
Type |
A1 Journal article |
| |
Year |
2013 |
Publication |
Journal of catalysis |
Abbreviated Journal |
J Catal |
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| |
Volume |
300 |
Issue |
|
Pages |
70-80 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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| |
Abstract |
MFI zeolite nanosheets with thickness of 2 and 8 nm were synthesized, transformed into bifunctional catalysts by loading with platinum and tested in n-decane isomerization and hydrocracking. Detailed analysis of skeletal isomers and hydrocracked products revealed that the MFI nanosheets display transition-state shape-selectivity similar to bulk MFI zeolite crystals. The suppressed formation of bulky skeletal isomers and C5 cracking products are observed both in the nanosheets and the bulk crystals grown in three dimensions. This is typical for restricted transition-state shape-selectivity, characteristic for the MFI type pores. It is a first clear example of transition-state shape-selectivity inside a zeolitic nanosheet. Owing to the short diffusion path across the sheets, expression of diffusion-based discrimination of reaction products in the MFI nanosheets was limited. The 2-methylnonane formation among monobranched C10 isomers and 2,7-dimethyloctane among dibranched C10 isomers, which in MFI zeolite are favored by product diffusion, was much less favored on the nanosheets compared to the reference bulk ZSM-5 material. |
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Address |
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Corporate Author |
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Thesis |
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| |
Publisher |
|
Place of Publication |
San Diego, Calif. |
Editor |
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| |
Language |
|
Wos |
000317558000009 |
Publication Date |
2013-02-07 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0021-9517; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
6.844 |
Times cited |
121 |
Open Access |
|
|
| |
Notes |
Methusalem; IAP; Countatoms |
Approved |
Most recent IF: 6.844; 2013 IF: 6.073 |
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| |
Call Number |
UA @ lucian @ c:irua:106186 |
Serial |
2181 |
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| Permanent link to this record |
| |
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| |
|
Author |
Sivek, J.; Sahin, H.; Partoens, B.; Peeters, F.M. |
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| |
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. |
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| |
Address |
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| |
Corporate Author |
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Thesis |
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| |
Publisher |
|
Place of Publication |
|
Editor |
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| |
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 |
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| |
Call Number |
UA @ lucian @ c:irua:107071 |
Serial |
60 |
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| Permanent link to this record |
| |
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| |
|
Author |
Saniz, R.; Partoens, B.; Peeters, F.M. |
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| |
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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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 |
000315374100009 |
Publication Date |
2013-02-25 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.836 |
Times cited |
6 |
Open Access |
|
|
| |
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl). R.S. thanks M. R. Norman, B. Soree, and L. Komendova for useful comments. ; |
Approved |
Most recent IF: 3.836; 2013 IF: 3.664 |
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| |
Call Number |
UA @ lucian @ c:irua:107072 |
Serial |
487 |
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| Permanent link to this record |
| |
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| |
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Author |
Yusupov, M.; Bogaerts, A.; Huygh, S.; Snoeckx, R.; van Duin, A.C.T.; Neyts, E.C. |
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| |
Title |
Plasma-induced destruction of bacterial cell wall components : a reactive molecular dynamics simulation |
Type |
A1 Journal article |
| |
Year |
2013 |
Publication |
The journal of physical chemistry: C : nanomaterials and interfaces |
Abbreviated Journal |
J Phys Chem C |
|
| |
Volume |
117 |
Issue |
11 |
Pages |
5993-5998 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
|
| |
Abstract |
Nonthermal atmospheric pressure plasmas are gaining increasing attention for biomedical applications. However, very little fundamental information on the interaction mechanisms between the plasma species and biological cells is currently available. We investigate the interaction of important plasma species, such as OH, H2O2, O, O3, as well as O2 and H2O, with bacterial peptidoglycan by means of reactive molecular dynamics simulations, aiming for a better understanding of plasma disinfection. Our results show that OH, O, O3, and H2O2 can break structurally important bonds of peptidoglycan (i.e., CO, CN, or CC bonds), which consequently leads to the destruction of the bacterial cell wall. The mechanisms behind these breakups are, however, dependent on the impinging plasma species, and this also determines the effectiveness of the cell wall destruction. |
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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 |
Washington, D.C. |
Editor |
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| |
Language |
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Wos |
000316773000056 |
Publication Date |
2013-02-23 |
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| |
Series Editor |
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Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
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Series Issue |
|
Edition |
|
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| |
ISSN |
1932-7447;1932-7455; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
4.536 |
Times cited |
59 |
Open Access |
|
|
| |
Notes |
|
Approved |
Most recent IF: 4.536; 2013 IF: 4.835 |
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| |
Call Number |
UA @ lucian @ c:irua:107154 |
Serial |
2636 |
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| Permanent link to this record |
| |
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| |
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Author |
da Pieve, F.; Di Matteo, S.; Rangel, T.; Giantomassi, M.; Lamoen, D.; Rignanese, G.-M.; Gonze, X. |
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| |
Title |
Origin of magnetism and quasiparticles properties in Cr-doped TiO2 |
Type |
A1 Journal article |
| |
Year |
2013 |
Publication |
Physical review letters |
Abbreviated Journal |
Phys Rev Lett |
|
| |
Volume |
110 |
Issue |
13 |
Pages |
136402-136405 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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| |
Abstract |
Combining the local spin density approximation (LSDA)+U and an analysis of superexchange interactions beyond density functional theory, we describe the magnetic ground state of Cr-doped TiO2, an intensively studied and debated dilute magnetic oxide. In parallel, we correct our LSDA+U (+ superexchange) ground state through GW corrections (GW@LSDA+U) that reproduce the position of the impurity states and the band gaps in satisfying agreement with experiments. Because of the different topological coordinations of Cr-Cr bonds in the ground states of rutile and anatase, superexchange interactions induce either ferromagnetic or antiferromagnetic couplings of Cr ions. In Cr-doped anatase, this interaction leads to a new mechanism which stabilizes a (nonrobust) ferromagnetic ground state, in keeping with experimental evidence, without the need to invoke F-center exchange. The interplay between structural defects and vacancies in contributing to the superexchange is also unveiled. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
New York, N.Y. |
Editor |
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| |
Language |
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Wos |
000316683500014 |
Publication Date |
2013-03-25 |
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| |
Series Editor |
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Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
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| |
ISSN |
0031-9007;1079-7114; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
8.462 |
Times cited |
15 |
Open Access |
|
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| |
Notes |
Goa; Iwt |
Approved |
Most recent IF: 8.462; 2013 IF: 7.728 |
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| |
Call Number |
UA @ lucian @ c:irua:107281 |
Serial |
2524 |
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| Permanent link to this record |
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| |
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Author |
Zelaya, E.; Esquivel, M.R.; Schryvers, D. |
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| |
Title |
Evolution of the phase stability of NiAl under low energy ball milling |
Type |
A1 Journal article |
| |
Year |
2013 |
Publication |
Advanced powder technology |
Abbreviated Journal |
Adv Powder Technol |
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| |
Volume |
24 |
Issue |
6 |
Pages |
1063-1069 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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| |
Abstract |
Low energy mechanical alloying of Ni35 at.%Al and Ni40 at.%Al material was performed and the resulting structures were investigated by XRD and TEM. The final intermetallics observed consist of two phases, NiAl(B2) and Ni3Al while 7R and 3R martensite was observed in post-annealed samples. Different integrated milling times were associated to the intermetallic consolidation and initial blend dissociation. |
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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 |
Zeist |
Editor |
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| |
Language |
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Wos |
000339175000024 |
Publication Date |
2013-03-30 |
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| |
Series Editor |
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Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
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Edition |
|
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| |
ISSN |
0921-8831; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
2.659 |
Times cited |
10 |
Open Access |
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| |
Notes |
Fwo |
Approved |
Most recent IF: 2.659; 2013 IF: 1.642 |
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| |
Call Number |
UA @ lucian @ c:irua:107345 |
Serial |
1102 |
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| Permanent link to this record |
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Author |
Vorobyeva, N.; Rumyantseva, M.; Filatova, D.; Konstantinova, E.; Grishina, D.; Abakumov, A.; Turner, S.; Gaskov, A. |
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| |
Title |
Nanocrystalline ZnO(Ga) : paramagnetic centers, surface acidity and gas sensor properties |
Type |
A1 Journal article |
| |
Year |
2013 |
Publication |
Sensors and actuators : B : chemical |
Abbreviated Journal |
Sensor Actuat B-Chem |
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| |
Volume |
182 |
Issue |
|
Pages |
555-564 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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| |
Abstract |
Nanocrystalline ZnO and ZnO(Ga) samples with different gallium content were prepared by wet-chemical method. Introduction of gallium leads to the increase of amount of weak acid sites such as surface hydroxyl groups. Gas sensing properties toward 0.22 ppm H2S and NO2 were studied at 100450 °C by DC conductance measurements. The optimal temperature for gas sensing experiments was determined. Sensor signal toward H2S decreases with increase of Ga concentration. The dependence of ZnO(Ga) sensor signal to NO2 on the gallium content has non-monotonous character, which correlates with the change of conductivity of the samples in air and concentration of paramagnetic donor states. |
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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 |
Lausanne |
Editor |
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| |
Language |
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Wos |
000319488800075 |
Publication Date |
2013-03-27 |
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| |
Series Editor |
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Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
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| |
ISSN |
0925-4005; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
5.401 |
Times cited |
42 |
Open Access |
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| |
Notes |
Hercules; FWO |
Approved |
Most recent IF: 5.401; 2013 IF: 3.840 |
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| |
Call Number |
UA @ lucian @ c:irua:107346 |
Serial |
2250 |
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| Permanent link to this record |
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Author |
Filippousi, M.; Papadimitriou, S.A.; Bikiaris, D.N.; Pavlidou, E.; Angelakeris, M.; Zamboulis, D.; Tian, H.; Van Tendeloo, G. |
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Title |
Novel coreshell magnetic nanoparticles for Taxol encapsulation in biodegradable and biocompatible block copolymers : preparation, characterization and release properties |
Type |
A1 Journal article |
| |
Year |
2013 |
Publication |
International journal of pharmaceutics |
Abbreviated Journal |
Int J Pharmaceut |
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| |
Volume |
448 |
Issue |
1 |
Pages |
221-230 |
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| |
Keywords |
A1 Journal article; Pharmacology. Therapy; Electron microscopy for materials research (EMAT) |
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| |
Abstract |
Theranostic polymeric nanocarriers loaded with anticancer drug Taxol and superparamagnetic iron oxide nanocrystals have been developed for possible magnetic resonance imaging (MRI) use and cancer therapy. Multifunctional nanocarriers with a coreshell structure have been prepared by coating superparamagnetic Fe3O4 nanoparticles with block copolymer of poly(ethylene glycol)-b-poly(propylene succinate) with variable molecular weights of the hydrophobic block poly(prolylene succinate). The multifunctional polymer nano-vehicles were prepared using a nanoprecipitation method. Scanning transmission electron microscopy revealed the encapsulation of magnetic nanoparticles inside the polymeric matrix. Energy dispersive X-ray spectroscopy and electron energy loss spectroscopy mapping allowed us to determine the presence of the different material ingredients in a quantitative way. The diameter of the nanoparticles is below 250 nm yielding satisfactory encapsulation efficiency. The nanoparticles exhibit a biphasic drug release pattern in vitro over 15 days depending on the molecular weight of the hydrophobic part of the polymer matrix. These new systems where anti-cancer therapeutics like Taxol and iron oxide nanoparticles (IOs) are co-encapsulated into new facile polymeric nanoparticles, could be addressed as potential multifunctional vehicles for simultaneous drug delivery and targeting imaging as well as real time monitoring of therapeutic effects. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Amsterdam |
Editor |
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| |
Language |
|
Wos |
000319052000026 |
Publication Date |
2013-03-21 |
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| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0378-5173; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.649 |
Times cited |
29 |
Open Access |
|
|
| |
Notes |
Countatoms |
Approved |
Most recent IF: 3.649; 2013 IF: 3.785 |
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| |
Call Number |
UA @ lucian @ c:irua:107348 |
Serial |
2374 |
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| Permanent link to this record |
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| |
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Author |
Neek-Amal, M.; Beheshtian, J.; Shayeganfar, F.; Singh, S.K.; Los, J.H.; Peeters, F.M. |
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| |
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 |
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| |
Volume |
87 |
Issue |
7 |
Pages |
075448-8 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
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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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 |
000315481800005 |
Publication Date |
2013-02-27 |
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| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
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| |
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.836 |
Times cited |
14 |
Open Access |
|
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| |
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 |
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| |
Call Number |
UA @ lucian @ c:irua:107654 |
Serial |
3106 |
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| Permanent link to this record |
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Author |
Zhang, S.H.; Xu, W.; Badalyan, S.M.; Peeters, F.M. |
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| |
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 |
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| |
Volume |
87 |
Issue |
7 |
Pages |
075443-75445 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
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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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 |
000315375200008 |
Publication Date |
2013-02-27 |
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| |
Series Editor |
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Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
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 |
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| |
Call Number |
UA @ lucian @ c:irua:107655 |
Serial |
2622 |
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| Permanent link to this record |
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Author |
Arsoski, V.V.; Tadić, M.Z.; Peeters, F.M. |
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| |
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 |
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| |
Volume |
87 |
Issue |
8 |
Pages |
085314-14 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
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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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 |
000315278000003 |
Publication Date |
2013-02-25 |
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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 |
|
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 |
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 |
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| |
Call Number |
UA @ lucian @ c:irua:107656 |
Serial |
3165 |
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| Permanent link to this record |
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Author |
Grujić, M.; Tadić, M.; Peeters, F.M. |
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| |
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 |
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| |
Volume |
87 |
Issue |
8 |
Pages |
085434-85436 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
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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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 |
000315146600005 |
Publication Date |
2013-02-20 |
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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 |
|
| |
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 |
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| |
Call Number |
UA @ lucian @ c:irua:107661 |
Serial |
137 |
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| Permanent link to this record |
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Author |
Sahin, H.; Peeters, F.M. |
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| |
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 |
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| |
Volume |
87 |
Issue |
8 |
Pages |
085423-85429 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
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 |
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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 |
000315146500008 |
Publication Date |
2013-02-19 |
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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 |
281 |
Open Access |
|
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| |
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 |
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| |
Call Number |
UA @ lucian @ c:irua:107663 |
Serial |
62 |
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| Permanent link to this record |
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Author |
Li, B.; Djotyan, A.P.; Hao, Y.L.; Avetisyan, A.A.; Peeters, F.M. |
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| |
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 |
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| |
Volume |
87 |
Issue |
7 |
Pages |
075313-75319 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
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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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 |
000314874800017 |
Publication Date |
2013-02-13 |
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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 |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
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 |
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| |
Call Number |
UA @ lucian @ c:irua:107664 |
Serial |
793 |
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| Permanent link to this record |
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Author |
Villegas, C.E.P.; Tavares, M.R.S.; Hai, G.-Q.; Peeters, F.M. |
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Title |
Sorting the modes contributing to guidance in strain-induced graphene waveguides |
Type |
A1 Journal article |
| |
Year |
2013 |
Publication |
New journal of physics |
Abbreviated Journal |
New J Phys |
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| |
Volume |
15 |
Issue |
|
Pages |
023015-11 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We propose a simple way of probing the number of modes contributing to the channeling in graphene waveguides which are formed by a gauge potential produced by mechanical strain. The energy mode structure for both homogeneous and non-homogeneous strain regimes is carefully studied using the continuum description of the Dirac equation. We found that high strain values privilege negative (instead of positive) group velocities throughout the guidance, sorting the types of modes flowing through it. We also show how the effect of a substrate-induced gap competes against the strain. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Bristol |
Editor |
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Language |
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Wos |
000314868000002 |
Publication Date |
2013-02-08 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1367-2630; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.786 |
Times cited |
7 |
Open Access |
|
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| |
Notes |
; This work was supported by FAPESP, CNPq and the Flemish Science Foundation (FWO-VI). ; |
Approved |
Most recent IF: 3.786; 2013 IF: 3.671 |
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| |
Call Number |
UA @ lucian @ c:irua:107667 |
Serial |
3056 |
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| Permanent link to this record |
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Author |
Zhu, J.-J.; Badalyan, S.M.; Peeters, F.M. |
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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 |
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| |
Volume |
87 |
Issue |
8 |
Pages |
085401-85408 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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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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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 |
000314682900005 |
Publication Date |
2013-02-05 |
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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 |
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| |
Impact Factor |
3.836 |
Times cited |
59 |
Open Access |
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| |
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 |
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Call Number |
UA @ lucian @ c:irua:107671 |
Serial |
2645 |
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| 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. |
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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 |
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| |
Volume |
87 |
Issue |
2 |
Pages |
024423-24429 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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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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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 |
000314224800002 |
Publication Date |
2013-02-01 |
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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 |
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 |
17 |
Open Access |
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| |
Notes |
|
Approved |
Most recent IF: 3.836; 2013 IF: 3.664 |
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Call Number |
UA @ lucian @ c:irua:107688 |
Serial |
1293 |
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| Permanent link to this record |
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Author |
Kirsanova, M.A.; Mori, T.; Maruyama, S.; Matveeva; Batuk, D.; Abakumov, A.M.; Gerasimenko, A.V.; Olenev, A.V.; Grin, Y.; Shevelkov, A.V. |
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Title |
Synthesis, structure, and transport properties of type-I derived clathrate Ge46-xPxSe8-y (x=15.4(1); y=0-2.65) with diverse host-guest bonding |
Type |
A1 Journal article |
| |
Year |
2013 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
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Volume |
52 |
Issue |
2 |
Pages |
577-588 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
A first clathrate compound with selenium guest atoms, [Ge46-xPx]Se8-y square(y) (x = 15.4(1); y = 0-2.65; square denotes a vacancy), was synthesized as a single-phase and structurally characterized. It crystallizes in the space group Fm (3) over bar with the unit cell parameter a varying from 20.310(2) to 20.406(2) angstrom and corresponding to a 2 x 2 x 2 supercell of a usual clathrate-I structure. The superstructure is formed due to the symmetrical arrangement of the three-bonded framework atoms appearing as a result of the framework transformation of the parent clathrate-I structure. Selenium guest atoms occupy two types of polyhedral cages inside the positively charged framework; all selenium atoms in the larger cages form a single covalent bond with the framework atoms, relating the title compounds to a scanty family of semiclathrates. According to the measurements of electrical resistivity and Seebeck coefficient, [Ge46-xPx]Se8-y square(y) is an n-type semiconductor with E-g = 0.41 eV for x = 15.4(1) and y = 0; it demonstrates the maximal thermoelectric power factor of 2.3 x 10(-5) W K-2 m(-1) at 660 K. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Easton, Pa |
Editor |
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Language |
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Wos |
000314007500010 |
Publication Date |
2012-12-31 |
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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 |
0020-1669;1520-510X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.857 |
Times cited |
14 |
Open Access |
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Notes |
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Approved |
Most recent IF: 4.857; 2013 IF: 4.794 |
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Call Number |
UA @ lucian @ c:irua:107689 |
Serial |
3463 |
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| Permanent link to this record |
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Author |
Houssa, M.; van den Broek, B.; Scalise, E.; Pourtois, G.; Afanas'ev, V.V.; Stesmans, A. |
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Title |
An electric field tunable energy band gap at silicene/(0001) ZnS interfaces |
Type |
A1 Journal article |
| |
Year |
2013 |
Publication |
Physical chemistry, chemical physics |
Abbreviated Journal |
Phys Chem Chem Phys |
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| |
Volume |
15 |
Issue |
11 |
Pages |
3702-3705 |
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Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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| |
Abstract |
The interaction of silicene, the silicon counterpart of graphene, with (0001) ZnS surfaces is investigated theoretically, using first-principles simulations. The charge transfer occurring at the silicene/(0001) ZnS interface leads to the opening of an indirect energy band gap of about 0.7 eV in silicene. Remarkably, the nature (indirect or direct) and magnitude of the energy band gap of silicene can be controlled by an external electric field: the energy gap is predicted to become direct for electric fields larger than about 0.5 V angstrom(-1), and the direct energy gap decreases approximately linearly with the applied electric field. The predicted electric field tunable energy band gap of the silicene/(0001) ZnS interface is very promising for its potential use in nanoelectronic 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 |
Cambridge |
Editor |
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Language |
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Wos |
000315165100002 |
Publication Date |
2013-01-29 |
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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 |
1463-9076;1463-9084; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
4.123 |
Times cited |
74 |
Open Access |
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Notes |
|
Approved |
Most recent IF: 4.123; 2013 IF: 4.198 |
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Call Number |
UA @ lucian @ c:irua:107702 |
Serial |
94 |
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| Permanent link to this record |
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Author |
Vasiliev, R.B.; Babynina, A.V.; Maslova, O.A.; Rumyantseva, M.N.; Ryabova, L.I.; Dobrovolsky, A.A.; Drozdov, K.A.; Khokhlov, D.R.; Abakumov, A.M.; Gaskov, A.M. |
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Title |
Photoconductivity of nanocrystalline SnO2 sensitized with colloidal CdSe quantum dots |
Type |
A1 Journal article |
| |
Year |
2013 |
Publication |
Journal of materials chemistry C : materials for optical and electronic devices |
Abbreviated Journal |
J Mater Chem C |
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Volume |
1 |
Issue |
5 |
Pages |
1005-1010 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
A highly reproducible photoresponse is observed in nanocrystalline SnO2 thick films sensitized with CdSe quantum dots. The effect of the SnO2 matrix microstructure on the photoconductivity kinetics and photoresponse amplitude is demonstrated. The photoresponse of the sensitized SnO2 thick films reaches more than two orders of magnitude under illumination with the wavelength of the excitonic transition of the quantum dots. Long-term photoconductivity kinetics and photoresponse dependence on illumination intensity reveal power-law behavior inherent to the disordered nature of SnO2. The photoconductivity of the samples rises with the coarsening of the granular structure of the SnO2 matrix. At the saturation region, the photoresponse amplitude remains stable under 10(4) pulses of illumination switching, demonstrating a remarkably high stability. |
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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 |
000314803600016 |
Publication Date |
2012-11-14 |
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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 |
|
Series Issue |
|
Edition |
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| |
ISSN |
2050-7526;2050-7534; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
5.256 |
Times cited |
13 |
Open Access |
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Notes |
|
Approved |
Most recent IF: 5.256; 2013 IF: NA |
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| |
Call Number |
UA @ lucian @ c:irua:107705 |
Serial |
2610 |
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| Permanent link to this record |
