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Author | Čukarić, N.A.; Tadić, M.Z.; Partoens, B.; Peeters, F.M. | ||||
Title | 30-band k\cdot p model of electron and hole states in silicon quantum wells | Type | A1 Journal article | ||
Year | 2013 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 88 | Issue | 20 | Pages | 205306 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | We modeled the electron and hole states in Si/SiO2 quantum wells within a basis of standing waves using the 30-band k . p theory. The hard-wall confinement potential is assumed, and the influence of the peculiar band structure of bulk silicon on the quantum-well sub-bands is explored. Numerous spurious solutions in the conduction-band and valence-band energy spectra are found and are identified to be of two types: (1) spurious states which have large contributions of the bulk solutions with large wave vectors (the high-k spurious solutions) and (2) states which originate mainly from the spurious valley outside the Brillouin zone (the extravalley spurious solutions). An algorithm to remove all those nonphysical solutions from the electron and hole energy spectra is proposed. Furthermore, slow and oscillatory convergence of the hole energy levels with the number of basis functions is found and is explained by the peculiar band mixing and the confinement in the considered quantum well. We discovered that assuming the hard-wall potential leads to numerical instability of the hole states computation. Nonetheless, allowing the envelope functions to exponentially decay in a barrier of finite height is found to improve the accuracy of the computed hole states. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000327161500007 | Publication Date | 2013-11-20 | |
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 | 10 | Open Access | |
Notes | ; This work was supported by the Ministry of Education, Science, and Technological Development of Serbia, the Belgian Science Policy (IAP), the Flemish fund for Scientific Research (FWO-Vl), and the Methusalem programme of the Flemish government. ; | Approved | Most recent IF: 3.836; 2013 IF: 3.664 | ||
Call Number | UA @ lucian @ c:irua:112704 | Serial | 18 | ||
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Author | Milovanovic, S.P.; Masir, M.R.; Peeters, F.M. | ||||
Title | Graphene hall bar with an asymmetric pn-junction | Type | A1 Journal article | ||
Year | 2013 | Publication | Journal of applied physics | Abbreviated Journal | J Appl Phys |
Volume | 113 | Issue | 19 | Pages | 193701-193708 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | We investigated the magnetic field dependence of the Hall and the bend resistances in the ballistic regime for a single layer graphene Hall bar structure containing a pn-junction. When both regions are n-type the Hall resistance dominates and Hall type of plateaus are formed. These plateaus occur as a consequence of the restriction on the angle imposed by Snell's law allowing only electrons with a certain initial angles to transmit though the potential step. The size of the plateau and its position is determined by the position of the potential interface as well as the value of the applied potential. When the second region is p-type, the bend resistance dominates, which is asymmetric in field due to the presence of snake states. Changing the position of the pn-interface in the Hall bar strongly affects these states and therefore the bend resistance is also changed. Changing the applied potential, we observe that the bend resistance exhibits a peak around the charge-neutrality point (CNP), which is independent of the position of the pn-interface, while the Hall resistance shows a sign reversal when the CNP is crossed, which is in very good agreement with a recent experiment [J. R. Williams and C. M. Marcus, Phys. Rev. Lett. 107, 046602 (2011)]. | ||||
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Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
Language | Wos | 000319295200022 | Publication Date | 2013-05-16 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0021-8979; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.068 | Times cited | 7 | Open Access | |
Notes | This work was supported by the Flemish Science Foundation (FWO-Vl), the European Science Foundation (ESF) under the EUROCORES Program EuroGRAPHENE within the project CONGRAN, and the Methusalem Foundation of the Flemish government. We acknowledge fruitful discussions with M. Barbier. | Approved | Most recent IF: 2.068; 2013 IF: 2.185 | ||
Call Number | UA @ lucian @ c:irua:108999 | Serial | 1371 | ||
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Author | Lubk, A.; Clark, L.; Guzzinati, G.; Verbeeck, J. | ||||
Title | Topological analysis of paraxially scattered electron vortex beams | Type | A1 Journal article | ||
Year | 2013 | Publication | Physical review : A : atomic, molecular and optical physics | Abbreviated Journal | Phys Rev A |
Volume | 87 | Issue | 3 | Pages | 033834-33838 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | We investigate topological aspects of subnanometer electron vortex beams upon elastic propagation through atomic scattering potentials. Two main aspects can be distinguished: (i) significantly reduced delocalization compared to a similar nonvortex beam if the beam centers on an atomic column and (ii) site symmetry dependent splitting of higher-order vortex beams. Furthermore, the results provide insight into the complex vortex line fabric within the elastically scattered wave containing characteristic vortex loops predominantly attached to atomic columns and characteristic twists of vortex lines around atomic columns. DOI: 10.1103/PhysRevA.87.033834 | ||||
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Publisher | American Physical Society | Place of Publication | New York, N.Y | Editor | |
Language | Wos | 000316790600011 | Publication Date | 2013-03-27 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1050-2947;1094-1622; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.925 | Times cited | 26 | Open Access | |
Notes | Countatoms; Vortex; Esteem2; esteem2jra3 ECASJO; | Approved | Most recent IF: 2.925; 2013 IF: 2.991 | ||
Call Number | UA @ lucian @ c:irua:108496 | Serial | 3673 | ||
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Author | Neyts, E.C.; van Duin, A.C.T.; Bogaerts, A. | ||||
Title | Formation of single layer graphene on nickel under far-from-equilibrium high flux conditions | Type | A1 Journal article | ||
Year | 2013 | Publication | Nanoscale | Abbreviated Journal | Nanoscale |
Volume | 5 | Issue | 16 | Pages | 7250-7255 |
Keywords | A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
Abstract | We investigate the theoretical possibility of single layer graphene formation on a nickel surface at different substrate temperatures under far-from-equilibrium high precursor flux conditions, employing state-of-the-art hybrid reactive molecular dynamics/uniform acceptance force bias Monte Carlo simulations. It is predicted that under these conditions, the formation of a single layer graphene-like film may proceed through a combined depositionsegregation mechanism on a nickel substrate, rather than by pure surface segregation as is typically observed for metals with high carbon solubility. At 900 K and above, nearly continuous graphene layers are obtained. These simulations suggest that single layer graphene deposition is theoretically possible on Ni under high flux conditions. | ||||
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Publisher | Place of Publication | Cambridge | Editor | ||
Language | Wos | 000322315600019 | Publication Date | 2013-04-26 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2040-3364;2040-3372; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 7.367 | Times cited | 25 | Open Access | |
Notes | Approved | Most recent IF: 7.367; 2013 IF: 6.739 | |||
Call Number | UA @ lucian @ c:irua:109249 | Serial | 1264 | ||
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Author | Zarenia, M.; Pereira, J.M., Jr.; Peeters, F.M.; Farias, G.A. | ||||
Title | Snake states in graphene quantum dots in the presence of a p-n junction | Type | A1 Journal article | ||
Year | 2013 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 87 | Issue | 3 | Pages | 035426 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | We investigate the magnetic interface states of graphene quantum dots that contain p-n junctions. Within a tight-binding approach, we consider rectangular quantum dots in the presence of a perpendicular magnetic field containing p-n as well as p-n-p and n-p-n junctions. The results show the interplay between the edge states associated with the zigzag terminations of the sample and the snake states that arise at the p-n junction due to the overlap between electron and hole states at the potential interface. Remarkable localized states are found at the crossing of the p-n junction with the zigzag edge having a dumb-bell-shaped electron distribution. The results are presented as a function of the junction parameters and the applied magnetic flux. DOI: 10.1103/PhysRevB.87.035426 | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000313941000003 | Publication Date | 2013-01-29 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1098-0121;1550-235X; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 16 | Open Access | |
Notes | ; This work was supported by the Flemish Science Foundation (FWO-VI), the European Science Foundation (ESF) under the EUROCORES program EuroGRAPHENE (project CONGRAN), the Brazilian agency CNPq (Pronex), and the bilateral projects between Flanders and Brazil and the collaboration project FWO-CNPq. ; | Approved | Most recent IF: 3.836; 2013 IF: 3.664 | ||
Call Number | UA @ lucian @ c:irua:110087 | Serial | 3048 | ||
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Author | Milovanovic, S.P.; Masir, M.R.; Peeters, F.M. | ||||
Title | Bilayer graphene Hall bar with a pn-junction | Type | A1 Journal article | ||
Year | 2013 | Publication | Journal of applied physics | Abbreviated Journal | J Appl Phys |
Volume | 114 | Issue | 11 | Pages | 113706 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | We investigate the magnetic field dependence of the Hall and the bend resistances for a ballistic Hall bar structure containing a pn-junction sculptured from a bilayer of graphene. The electric response is obtained using the billiard model, and we investigate the cases of bilayer graphene with and without a band gap. Two different conduction regimes are possible: (i) both sides of the junction have the same carrier type and (ii) one side of the junction is n-type while the other one is p-type. The first case shows Hall plateau-like features in the Hall resistance that fade away as the band gap opens. The second case exhibits a bend resistance that is asymmetric in magnetic field as a consequence of snake states along the pn-interface, where the maximum is shifted away from zero magnetic field. | ||||
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Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
Language | Wos | 000324827200031 | Publication Date | 2013-09-17 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0021-8979; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.068 | Times cited | 3 | Open Access | |
Notes | This work was supported by the Flemish Science Foundation (FWO-Vl), the European Science Foundation (ESF) under the EUROCORES Program EuroGRAPHENE within the project CONGRAN, and the Methusalem Foundation of the Flemish government. | Approved | Most recent IF: 2.068; 2013 IF: 2.185 | ||
Call Number | UA @ lucian @ c:irua:111169 | Serial | 234 | ||
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Author | Couet, S.; Peelaers, H.; Trekels, M.; Houben, K.; Petermann, C.; Hu, M.Y.; Zhao, J.Y.; Bi, W.; Alp, E.E.; Menéndez, E.; Partoens, B.; Peeters, F.M.; Van Bael, M.J.; Vantomme, A.; Temst, K.; | ||||
Title | Interplay between lattice dynamics and superconductivity in Nb3Sn thin films | Type | A1 Journal article | ||
Year | 2013 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 88 | Issue | 4 | Pages | 045437-7 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | We investigate the link between superconductivity and atomic vibrations in Nb3Sn films with a thickness ranging from 10 to 50 nm. The challenge of measuring the phonon density of states (PDOS) of these films has been tackled by employing the technique of nuclear inelastic scattering by Sn-119 isotopes to reveal the Sn-partial phonon density of states. With the support of ab initio calculations, we evaluate the effect of reduced film thickness on the PDOS. This approach allows us to estimate the changes in superconducting critical temperature T-c induced by phonon confinement, which turned out to be limited to a few tenths of K. The presented method is successful for the Nb3Sn system and paves the way for more systematic studies of the role of phonon confinement in Sn-containing superconductors. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000322529900004 | Publication Date | 2013-07-27 | |
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 | 5 | Open Access | |
Notes | ; The authors would like to cordially thank Dr. Rudolf Ruffer from the nuclear resonant scattering group of the ESRF for the support and gratefully acknowledge the ESRF for providing beamtime for the preliminary phonon study. S. C., K. H., and E. M. thank the Flemish Science Foundation (FWO-Vl) for their personal fellowship. This work was supported by FWO-Vl, the Methusalem program of the Flemish government, and the Concerted Research Action program (GOA/09/ 006) and (GOA/14/007). Use of the Advanced Photon Source, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science by Argonne National Laboratory, was supported by the U.S. DOE under Contract No. DE-AC02-06CH11357. ; | Approved | Most recent IF: 3.836; 2013 IF: 3.664 | ||
Call Number | UA @ lucian @ c:irua:109801 | Serial | 1702 | ||
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Author | Li, B.; Djotyan, A.P.; Hao, Y.L.; Avetisyan, A.A.; Peeters, F.M. | ||||
Title | Effect of a perpendicular magnetic field on the shallow donor states near a semiconductor-metal interface | Type | A1 Journal article | ||
Year | 2013 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 87 | Issue | 7 | Pages | 075313-75319 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | We investigate the influence of an external perpendicular magnetic field on the lowest-energy states of an electron bound to a donor which is located near a semiconductor-metal interface. The problem is treated within the effective mass approach and the lowest-energy states are obtained through (1) the “numerically exact” finite element method, and (2) a variational approach using a trial wave function where all image charges that emerge due to the presence of the metallic gate are taken into account. The trial wave functions are constructed such that they reduce to an exponential behavior for sufficiently small magnetic fields and become Gaussian for intermediate and large magnetic fields. The average electron-donor distance can be controlled by the external magnetic field. We find that the size of the 2p(z) state depends strongly on the magnetic field when the donor is close to the interface, showing a nonmonotonic behavior, in contrast with the ground and the other excited states. DOI: 10.1103/PhysRevB.87.075313 | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000314874800017 | Publication Date | 2013-02-13 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1098-0121;1550-235X; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 1 | Open Access | |
Notes | ; This work was supported by the Flemish Science Foundation (FWO-Vl). ; | Approved | Most recent IF: 3.836; 2013 IF: 3.664 | ||
Call Number | UA @ lucian @ c:irua:107664 | Serial | 793 | ||
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Author | Dantas, D.S.; Chaves, A.; Farias, G.A.; Ramos, A.C.A.; Peeters, F.M. | ||||
Title | Low-dimensional confining structures on the surface of helium films suspended on designed cavities | Type | A1 Journal article | ||
Year | 2013 | Publication | Journal of low temperature physics | Abbreviated Journal | J Low Temp Phys |
Volume | 173 | Issue | 3-4 | Pages | 207-226 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | We investigate the formation of quantum confined structures on the surface of a liquid helium film suspended on a nanostructured substrate. We show theoretically that, by nanostructuring the substrate, it is possible to change the geometry of the liquid helium surface, opening the possibility of designing and controlling the formation of valleys with different shapes. By applying an external electric field perpendicular to the substrate plane, surface electrons can be trapped into these valleys, as in a quantum dot. We investigate how the external parameters, such as the electric field strength and the height of the liquid helium bath, can be tuned to control the energy spectrum of the trapped surface electrons. | ||||
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Publisher | Place of Publication | New York | Editor | ||
Language | Wos | 000324820300008 | Publication Date | 2013-08-22 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0022-2291;1573-7357; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 1.3 | Times cited | 1 | Open Access | |
Notes | ; This work has received financial support from the Brazilian National Research Council (CNPq), Fundacao Cearense de Apoio ao Desenvolvimento Cientifico e Tecnologico (Funcap), CAPES and Pronex/CNPq/Funcap. This work was partially supported by the Flemish Science Foundation (FWO-Vl) and the bilateral project between CNPq and FWO-Vl. ; | Approved | Most recent IF: 1.3; 2013 IF: 1.036 | ||
Call Number | UA @ lucian @ c:irua:111140 | Serial | 1845 | ||
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Author | Shakouri, K.; Masir, M.R.; Jellal, A.; Choubabi, E.B.; Peeters, F.M. | ||||
Title | Effect of spin-orbit couplings in graphene with and without potential modulation | Type | A1 Journal article | ||
Year | 2013 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 88 | Issue | 11 | Pages | 115408-115409 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | We investigate the effect of Rashba and intrinsic spin-orbit couplings on the electronic properties and spin configurations of Dirac fermions confined in: (i) a flat graphene sheet, (ii) a graphene wire with p-n-p structure, and (iii) a superlattice of graphene wires. The interplay between the spin-orbit interaction mechanisms breaks the electron-hole symmetry and the spin configuration induced by Rashba spin-orbit coupling lacks inversion symmetry in k space. We show that the Rashba spin-orbit interaction doubles the Fabry-Perot resonant modes in the transmission spectrum of a graphene wire and opens new channels for the electron transmission. Moreover, it leads to the appearance of spin split extra Dirac cones in the energy spectrum of a graphene superlattice. It is shown that the spin of the electrons and holes confined in a flat graphene sheet is always perpendicular to their motion while this is not the case for the other nanostructures. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000323944600005 | Publication Date | 2013-09-05 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1098-0121;1550-235X; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 36 | Open Access | |
Notes | ; This work was supported by the Flemish Science Foundation (FWO-Vl) and the European Science Foundation (ESF) under the EUROCORES Program EuroGRAPHENE within the project CONGRAN. The generous support provided by the Saudi Center for Theoretical Physics (SCTP) is highly appreciated by A.J. and E.B.C. They also thank the Deanship of Scientific Research at King Faisal University for funding this work under the Project No. 130193. ; | Approved | Most recent IF: 3.836; 2013 IF: 3.664 | ||
Call Number | UA @ lucian @ c:irua:110716 | Serial | 836 | ||
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Author | Borgatti, F.; Park, C.; Herpers, A.; Offi, F.; Egoavil, R.; Yamashita, Y.; Yang, A.; Kobata, M.; Kobayashi, K.; Verbeeck, J.; Panaccione, G.; Dittmann, R.; | ||||
Title | Chemical insight into electroforming of resistive switching manganite heterostructures | Type | A1 Journal article | ||
Year | 2013 | Publication | Nanoscale | Abbreviated Journal | Nanoscale |
Volume | 5 | Issue | 9 | Pages | 3954-3960 |
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
Abstract | We have investigated the role of the electroforming process in the establishment of resistive switching behaviour for Pt/Ti/Pr0.5Ca0.5MnO3/SrRuO3 layered heterostructures (Pt/Ti/PCMO/SRO) acting as non-volatile Resistance Random Access Memories (RRAMs). Electron spectroscopy measurements demonstrate that the higher resistance state resulting from electroforming of as-prepared devices is strictly correlated with the oxidation of the top electrode Ti layer through field-induced electromigration of oxygen ions. Conversely, PCMO exhibits oxygen depletion and downward change of the chemical potential for both resistive states. Impedance spectroscopy analysis, supported by the detailed knowledge of these effects, provides an accurate model description of the device resistive behaviour. The main contributions to the change of resistance from the as-prepared (low resistance) to the electroformed (high resistance) states are respectively due to reduced PCMO at the boundary with the Ti electrode and to the formation of an anisotropic np junction between the Ti and the PCMO layers. | ||||
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Publisher | Place of Publication | Cambridge | Editor | ||
Language | Wos | 000317859400051 | Publication Date | 2013-03-05 | |
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Series Volume | Series Issue | Edition | |||
ISSN | 2040-3364;2040-3372; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 7.367 | Times cited | 40 | Open Access | |
Notes | Vortex; Countatoms ECASJO_; | Approved | Most recent IF: 7.367; 2013 IF: 6.739 | ||
Call Number | UA @ lucian @ c:irua:108710UA @ admin @ c:irua:108710 | Serial | 348 | ||
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Author | Retuerto, M.; Li, M.R.; Ignatov, A.; Croft, M.; Ramanujachary, K.V.; Chi, S.; Hodges, J.P.; Dachraoui, W.; Hadermann, J.; Tran, T.T.; Halasyamani, P.S.; Grams, C.P.; Hemberger, J.; Greenblatt, M.; | ||||
Title | Polar and magnetic layered A-site and rock salt B-site-ordered NaLnFeWO6 (Ln = La, Nd) perovskites | Type | A1 Journal article | ||
Year | 2013 | Publication | Inorganic chemistry | Abbreviated Journal | Inorg Chem |
Volume | 52 | Issue | 21 | Pages | 12482-12491 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | We have expanded the double perovskite family of materials with the unusual combination of layered order in the A sublattice and rock salt order over the B sublattice to compounds NaLaFeWO6 and NaNdFeWO6. The materials have been synthesized and studied by powder X-ray diffraction, neutron diffraction, electron diffraction, magnetic measurements, X-ray absorption spectroscopy, dielectric measurements, and second harmonic generation. At room temperature, the crystal structures of both compounds can be defined in the noncentrosymmetric monoclinic P2(1) space group resulting from the combination of ordering both in the A and B sublattices, the distortion of the cell due to tilting of the octahedra, and the displacement of certain cations. The magnetic studies show that both compounds are ordered antiferromagnetically below T-N approximate to 25 K for NaLaFeWO6 and at similar to 21 K for NaNdFeWO6. The magnetic structure of NaNdFeWO6 has been solved with a propagation vector k = (1/2 0 1/2) as an antiferromagnetic arrangement of Fe and Nd moments. Although the samples are potential multiferroics, the dielectric measurements do not show a ferroelectric response. | ||||
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Publisher | Place of Publication | Easton, Pa | Editor | ||
Language | Wos | 000326669200035 | Publication Date | 2013-10-18 | |
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Series Volume | Series Issue | Edition | |||
ISSN | 0020-1669;1520-510X; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.857 | Times cited | 17 | Open Access | |
Notes | Approved | Most recent IF: 4.857; 2013 IF: 4.794 | |||
Call Number | UA @ lucian @ c:irua:112714 | Serial | 2656 | ||
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Author | Vereecke, B.; van der Veen, M.H.; Sugiura, M.; Kashiwagi, Y.; Ke, X.; Cott, D.J.; Hantschel, T.; Huyghebaert, C.; Tökei, Z. | ||||
Title | Wafer-level electrical evaluation of vertical carbon nanotube bundles as a function of growth temperature | Type | A1 Journal article | ||
Year | 2013 | Publication | Japanese journal of applied physics | Abbreviated Journal | Jpn J Appl Phys |
Volume | 52 | Issue | 42 | Pages | 04cn02-5 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | We have evaluated the resistance of carbon nanotubes (CNTs) grown at a CMOS-compatible temperature using a realistic integration scheme. The structural analysis of the CNTs by transmission electron microscopy (TEM) showed that the degree of graphitization decreased significantly when the growth temperature was decreased from 540 to 400 °C. The CNTs were integrated to form 150-nm-diameter vertical interconnects between a TiN layer and Cu metal trenches on 200 mm full wafers. Wafers with CNTs grown at low temperature were found to have a lower single-contact resistance than those produced at high temperatures. Thickness measurements showed that the low contact resistance is a result of small contact height. This height dependence is masking the impact of CNT graphitization quality on resistance. When benchmarking our results with data from the literature, a relationship between resistivity and growth temperature cannot be found for CNT-based vertical interconnects. | ||||
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Publisher | Place of Publication | Kyoto | Editor | ||
Language | Wos | 000320002400150 | Publication Date | 2013-03-22 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0021-4922;1347-4065; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 1.384 | Times cited | 5 | Open Access | |
Notes | Approved | Most recent IF: 1.384; 2013 IF: 1.057 | |||
Call Number | UA @ lucian @ c:irua:108713 | Serial | 3902 | ||
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Author | Cornil, D.; Li, H.; Wood, C.; Pourtois, G.; Bredas, J.-L.; Cornil, J. | ||||
Title | Work-function modification of Au and Ag surfaces upon deposition of self-assembled monolayers : influence of the choice of the theoretical approach and the thiol decomposition scheme | Type | A1 Journal article | ||
Year | 2013 | Publication | ChemPhysChem : a European journal of chemical physics and physical chemistry | Abbreviated Journal | Chemphyschem |
Volume | 14 | Issue | 13 | Pages | 2939-2946 |
Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
Abstract | We have characterized theoretically the work-function modifications of the (111) surfaces of gold and silver upon deposition of self-assembled monolayers based on methanethiol and trifluoromethanethiol. A comparative analysis is made between the experimental results and those obtained from two widely used approaches based on density functional theory. The contributions to the total work-function modifications are estimated on the basis of two decomposition schemes of the thiol molecules that have been proposed in the literature. The contributions are found to differ significantly between the two approaches, as do the corresponding adsorption energies. | ||||
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Publisher | Place of Publication | Weinheim | Editor | ||
Language | Wos | 000324316000014 | Publication Date | 2013-07-15 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1439-4235; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.075 | Times cited | 9 | Open Access | |
Notes | Approved | Most recent IF: 3.075; 2013 IF: 3.360 | |||
Call Number | UA @ lucian @ c:irua:112278 | Serial | 3923 | ||
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Author | H. Zhang, N. Gauquelin, G.A. Botton and J.Y.T. Wei | ||||
Title | Attenuation of superconductivity in manganite/cuprate heterostructures by epitaxially induced CuO intergrowths | Type | A1 Journal Article | ||
Year | 2013 | Publication | Applied Physics Letters | Abbreviated Journal | |
Volume | 103 | Issue | Pages | 052606 | |
Keywords | A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; | ||||
Abstract | We examine the effect of CuO intergrowths on the superconductivity in epitaxial La 2/3 Ca 1/3 MnO 3 / YBa 2 Cu 3 O 7−δ La2/3Ca1/3MnO3/YBa2Cu3O7−δ (LCMO/YBCO) thin-film heterostructures. Scanning transmission electron microscopy on bilayer LCMO/YBCO thin films revealed double CuO-chain intergrowths which form regions with the 247 lattice structure in the YBCO layer. These nanoscale 247 regions do not appear in x-ray diffraction, but can physically account for the reduced critical temperature (Tc) of bilayer thin films relative to unilayer films with the same YBCO thickness, at least down to ∼25 nm. We attribute the CuO intergrowths to the bilayer heteroepitaxial mismatch and the Tc reduction to the generally lower Tc seen in bulk 247 samples. These epitaxially-induced CuO intergrowths provide a microstructural mechanism for the attenuation of superconductivity in LCMO/YBCO heterostructures. |
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000322723000063 | Publication Date | 2013-08-02 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | ISBN | Additional Links | |||
Impact Factor | Times cited | 12 | Open Access | ||
Notes | Approved | Most recent IF: NA | |||
Call Number | EMAT @ emat @ | Serial | 4546 | ||
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Author | Becker, T.; Nelissen, K.; Cleuren, B.; Partoens, B.; van den Broeck, C. | ||||
Title | Diffusion of interacting particles in discrete geometries | Type | A1 Journal article | ||
Year | 2013 | Publication | Physical review letters | Abbreviated Journal | Phys Rev Lett |
Volume | 111 | Issue | 11 | Pages | 110601 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | We evaluate the self-diffusion and transport diffusion of interacting particles in a discrete geometry consisting of a linear chain of cavities, with interactions within a cavity described by a free-energy function. Exact analytical expressions are obtained in the absence of correlations, showing that the self-diffusion can exceed the transport diffusion if the free-energy function is concave. The effect of correlations is elucidated by comparison with numerical results. Quantitative agreement is obtained with recent experimental data for diffusion in a nanoporous zeolitic imidazolate framework material, ZIF-8. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | New York, N.Y. | Editor | ||
Language | Wos | 000324233800001 | Publication Date | 2013-09-11 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0031-9007;1079-7114; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 8.462 | Times cited | 22 | Open Access | |
Notes | ; This work was supported by the Flemish Science Foundation (FWO-Vlaanderen). ; | Approved | Most recent IF: 8.462; 2013 IF: 7.728 | ||
Call Number | UA @ lucian @ c:irua:111176 | Serial | 699 | ||
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Author | Elliott, J.A.; Shibuta, Y.; Amara, H.; Bichara, C.; Neyts, E.C. | ||||
Title | Atomistic modelling of CVD synthesis of carbon nanotubes and graphene | Type | A1 Journal article | ||
Year | 2013 | Publication | Nanoscale | Abbreviated Journal | Nanoscale |
Volume | 5 | Issue | 15 | Pages | 6662-6676 |
Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
Abstract | We discuss the synthesis of carbon nanotubes (CNTs) and graphene by catalytic chemical vapour deposition (CCVD) and plasma-enhanced CVD (PECVD), summarising the state-of-the-art understanding of mechanisms controlling their growth rate, chiral angle, number of layers (walls), diameter, length and quality (defects), before presenting a new model for 2D nucleation of a graphene sheet from amorphous carbon on a nickel surface. Although many groups have modelled this process using a variety of techniques, we ask whether there are any complementary ideas emerging from the different proposed growth mechanisms, and whether different modelling techniques can give the same answers for a given mechanism. Subsequently, by comparing the results of tight-binding, semi-empirical molecular orbital theory and reactive bond order force field calculations, we demonstrate that graphene on crystalline Ni(111) is thermodynamically stable with respect to the corresponding amorphous metal and carbon structures. Finally, we show in principle how a complementary heterogeneous nucleation step may play a key role in the transformation from amorphous carbon to graphene on the metal surface. We conclude that achieving the conditions under which this complementary crystallisation process can occur may be a promising method to gain better control over the growth processes of both graphene from flat metal surfaces and CNTs from catalyst nanoparticles. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Cambridge | Editor | ||
Language | Wos | 000321675600003 | Publication Date | 2013-06-06 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2040-3364;2040-3372; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 7.367 | Times cited | 52 | Open Access | |
Notes | Approved | Most recent IF: 7.367; 2013 IF: 6.739 | |||
Call Number | UA @ lucian @ c:irua:109231 | Serial | 200 | ||
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Author | Shakouri, K.; Badalyan, S.M.; Peeters, F.M. | ||||
Title | Helical liquid of snake states | Type | A1 Journal article | ||
Year | 2013 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 88 | Issue | 19 | Pages | 195404-195405 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | We derive an exact solution to the problem of spin snake states induced in a nonhomogeneous magnetic field by a combined action of the Rashba spin-orbit and Zeeman fields. The electron spin behavior as a function of the cyclotron orbit center position and an external homogeneous magnetic field was obtained. It is shown that in an antisymmetric magnetic field the electron spin in the snake states has only an in-plane projection, perpendicular to the magnetic interface, which vanishes at large positive momenta. Applying an external homogeneous magnetic field adds a finite out-of-plane spin component and simultaneously gaps out the spectral branches, which results in regular beating patterns of the spin current components. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000326820200007 | Publication Date | 2013-11-07 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1098-0121;1550-235X; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 3 | Open Access | |
Notes | ; This work was supported by the Methusalem program of the Flemish government and the Flemish Science Foundation (FWO-Vl). ; | Approved | Most recent IF: 3.836; 2013 IF: 3.664 | ||
Call Number | UA @ lucian @ c:irua:112712 | Serial | 1416 | ||
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Author | Bittencourt, C.; Ke, X.; Van Tendeloo, G.; Tagmatarchis, N.; Guttmann, P. | ||||
Title | NEXAFS spectromicroscopy of suspended carbon nanohorns | Type | A1 Journal article | ||
Year | 2013 | Publication | Chemical physics letters | Abbreviated Journal | Chem Phys Lett |
Volume | 587 | Issue | Pages | 85-87 | |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | We demonstrate that near-edge X-ray-absorption fine-structure spectroscopy combined with full-field transmission X-ray microscopy can be used to study the electronic structure of suspended carbon nanohorns. Based on reports of electronic structure calculations additional spectral features observed in the π region of the NEXAFS spectrum recorded on the carbon nanohorns were associated to the presence of the pentagonal rings and the folding of the graphene sheet. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Amsterdam | Editor | ||
Language | Wos | 000326104500016 | Publication Date | 2013-09-18 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0009-2614; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 1.815 | Times cited | 4 | Open Access | |
Notes | Fp7; Countatoms; | Approved | Most recent IF: 1.815; 2013 IF: 1.991 | ||
Call Number | UA @ lucian @ c:irua:111592 | Serial | 2339 | ||
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Author | De Beule, C.; Partoens, B. | ||||
Title | Gapless interface states at the junction between two topological insulators | Type | A1 Journal article | ||
Year | 2013 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 87 | Issue | 11 | Pages | 115113-115116 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | We consider a junction between two topological insulators and calculate the properties of the interface states with an effective low-energy Hamiltonian for topological insulators with a single cone on the surface. This system bears a close resemblance to bilayer graphene, as both result from the hybridization of Dirac cones. We find gapless interface states not only when the helicity directions of the topological surface states are oppositely oriented, but they can also exist if they are equally oriented. Furthermore, we find that the existence of the interface states can be understood from the closing of the bulk gap when the helicity changes orientation. Recently superluminal tachyonic excitations were also claimed to exist at the interface between topological insulators. However, here we show that these interface states do not exist. DOI: 10.1103/PhysRevB.87.115113 | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000316101100002 | Publication Date | 2013-03-08 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1098-0121;1550-235X; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 8 | Open Access | |
Notes | ; The authors would like to thank Dr. O. Leenaerts for the helpful discussions. This work was supported by the Research Foundation Flanders (FWO). ; | Approved | Most recent IF: 3.836; 2013 IF: 3.664 | ||
Call Number | UA @ lucian @ c:irua:108282 | Serial | 1316 | ||
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Author | Drozhzhin, O.A.; Vorotyntsev, M.A.; Maduar, S.R.; Khasanova, N.R.; Abakumov, A.M.; Antipov, E.V. | ||||
Title | Li-ion diffusion in LixNb9PO25 | Type | A1 Journal article | ||
Year | 2013 | Publication | Electrochimica acta | Abbreviated Journal | Electrochim Acta |
Volume | 89 | Issue | Pages | 262-269 | |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Wadsley-Roth phase LixNb6PO25 has been studied as a potential candidate for anode material of Li-ion batteries. Its crystal structure, which consists of ReO3-type blocks of NbO6 octahedra connected with PO4 tetrahedra, provides a good stability and performance during Li+ insertion/removal. Li-ion chemical diffusion coefficient (D-chem) in LixNb6PO25 was determined by means of potentiostatic intermittent titration technique and electrochemical impedance spectroscopy. Different data treatments (classical Warburg equation or the model of an electrode system with ohmic potential drop and/or slow kinetics of the interfacial Li+ ion transfer across the electrode/electrolyte interface) were used for calculation of D-chem of the Li ion inside this material; their applicability is discussed in the article. D-chem changes with the Li-ion doping degree, x, in LixNb3PO25 and has a sharp minimum near the two-phase region at appr. 1.7V vs. Li+/Li. These values of D-chem in LixNb9PO25 (similar to 10(-9)-10(-11) cm(2) s(-1)) were found to be in average noticeably higher than in the widely studied anode material, Li4Ti5O12. (C) 2012 Elsevier Ltd. All rights reserved. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | London | Editor | ||
Language | Wos | 000315558200034 | Publication Date | 2012-11-14 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0013-4686; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.798 | Times cited | 11 | Open Access | |
Notes | Approved | Most recent IF: 4.798; 2013 IF: 4.086 | |||
Call Number | UA @ lucian @ c:irua:108312 | Serial | 1816 | ||
Permanent link to this record | |||||
Author | Berdiyorov, G.R.; Doria, M.M.; de Romaguera, A.R.C.; Milošević, M.V.; Brandt, E.H.; Peeters, F.M. | ||||
Title | Current-induced cutting and recombination of magnetic superconducting vortex loops in mesoscopic superconductor-ferromagnet heterostructures | Type | A1 Journal article | ||
Year | 2013 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 87 | Issue | 18 | Pages | 184508-5 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Vortex loops are generated by the inhomogeneous stray field of a magnetic dipole on top of a current-carrying mesoscopic superconductor. Cutting and recombination processes unfold under the applied drive, resulting in periodic voltage oscillations across the sample. We show that a direct and detectable consequence of the cutting and recombination of these vortex loops in the present setup is the onset of vortices at surfaces where they were absent prior to the application of the external current. The nonlinear dynamics of vortex loops is studied within the time-dependent Ginzburg-Landau theory to describe the profound three-dimensional features of their time evolution. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000319252000008 | Publication Date | 2013-05-21 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1098-0121;1550-235X; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 13 | Open Access | |
Notes | ; This work was supported by the Flemish Science Foundation (FWO-VI) and the bilateral programme between Flanders and Brazil. G.R.B. acknowledges support from FWO-VI. A.R. de C.R. acknowledges CNPq for financial support. ; | Approved | Most recent IF: 3.836; 2013 IF: 3.664 | ||
Call Number | UA @ lucian @ c:irua:109648 | Serial | 593 | ||
Permanent link to this record | |||||
Author | Lu, Y.-G.; Turner, S.; Verbeeck, J.; Janssens, S.D.; Haenen, K.; Van Tendeloo, G. | ||||
Title | Local bond length variations in boron-doped nanocrystalline diamond measured by spatially resolved electron energy-loss spectroscopy | Type | A1 Journal article | ||
Year | 2013 | Publication | Applied physics letters | Abbreviated Journal | Appl Phys Lett |
Volume | 103 | Issue | 3 | Pages | 032105-5 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Variations in local bond length and coordination in boron-doped nanocrystalline diamond (NCD) films have been studied through changes in the fine structure of boron and carbon K-edges in electron energy-loss spectra, acquired in a scanning transmission electron microscope. The presence of high concentrations of B in pristine diamond regions and enrichment of B at defects in single NCD grains is demonstrated. Local bond length variations are evidenced through an energy shift of the carbon 1s → σ* edge at B-rich defective regions within single diamond grains, indicating an expansion of the diamond bond length at sites with local high B content. | ||||
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Corporate Author | Thesis | ||||
Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
Language | Wos | 000322146300049 | Publication Date | 2013-07-17 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0003-6951; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.411 | Times cited | 15 | Open Access | |
Notes | Iap P6/42; Fwo G056810n; 262348 Esmi; 246791 Countatoms; 278510 Vortex; Fwo ECASJO_; | Approved | Most recent IF: 3.411; 2013 IF: 3.515 | ||
Call Number | UA @ lucian @ c:irua:109210UA @ admin @ c:irua:109210 | Serial | 1824 | ||
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Author | Geurts, R.; Milošević, M.V.; Albino Aguiar, J.; Peeters, F.M. | ||||
Title | Enhanced stability of vortex-antivortex states in two-component mesoscopic superconductors | Type | A1 Journal article | ||
Year | 2013 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 87 | Issue | 2 | Pages | 024501-24508 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Using the Ginzburg-Landau (GL) theory, we calculate the stability of sample symmetry-induced vortex-antivortex molecules in a mesoscopic superconducting bilayer exposed to a homogeneous magnetic field. We demonstrate the conditions under which the two condensates cooperatively broaden the field-temperature stability range of the composite (joint) vortex-antivortex state. In cases when such broadening is not achieved, a reentrance of the vortex-antivortex state is found at lower temperatures. In a large portion of the phase diagram noncomposite states are possible, in which the antivortex is present in only one of the layers. In this case, we demonstrate that the vortex-antivortex molecule in one of the layers can be pinned and enlarged by interaction with a vortex molecule in the other. Using analogies in the respective GL formalisms, we map our findings for the bilayer onto mesoscopic two-band superconductors. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000313029800003 | Publication Date | 2013-01-04 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1098-0121;1550-235X; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 25 | Open Access | |
Notes | ; This work was supported by the Flemish Science Foundation (FWO-Vlaanderen), the Brazilian science agencies FACEPE/CNPq under Grant No. APQ-0589-1.05/08 and CNPq under Grant No. 309832/2007-1, and the CNPq-FWO cooperation program under Grant No. 490681/2010-7. M.V.M. acknowledges support from the CAPES-PVE program. ; | Approved | Most recent IF: 3.836; 2013 IF: 3.664 | ||
Call Number | UA @ lucian @ c:irua:105925 | Serial | 1058 | ||
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Author | Muñoz, W.A.; Covaci, L.; Peeters, F.M. | ||||
Title | Tight-binding description of intrinsic superconducting correlations in multilayer graphene | Type | A1 Journal article | ||
Year | 2013 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 87 | Issue | 13 | Pages | 134509-7 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Using highly efficient GPU-based simulations of the tight-binding Bogoliubov-de Gennes equations we solve self-consistently for the pair correlation in rhombohedral (ABC) and Bernal (ABA) multilayer graphene by considering a finite intrinsic s-wave pairing potential. We find that the two different stacking configurations have opposite bulk/surface behavior for the order parameter. Surface superconductivity is robust for ABC stacked multilayer graphene even at very low pairing potentials for which the bulk order parameter vanishes, in agreement with a recent analytical approach. In contrast, for Bernal stacked multilayer graphene, we find that the order parameter is always suppressed at the surface and that there exists a critical value for the pairing potential below which no superconducting order is achieved. We considered different doping scenarios and find that homogeneous doping strongly suppresses surface superconductivity while nonhomogeneous field-induced doping has a much weaker effect on the superconducting order parameter. For multilayer structures with hybrid stacking (ABC and ABA) we find that when the thickness of each region is small (few layers), high-temperature surface superconductivity survives throughout the bulk due to the proximity effect between ABC/ABA interfaces where the order parameter is enhanced. DOI: 10.1103/PhysRevB.87.134509 | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000317390000006 | Publication Date | 2013-04-11 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1098-0121;1550-235X; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 37 | Open Access | |
Notes | ; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem funding of the Flemish Government. ; | Approved | Most recent IF: 3.836; 2013 IF: 3.664 | ||
Call Number | UA @ lucian @ c:irua:108469 | Serial | 3660 | ||
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Author | Singh, S.K.; Neek-Amal, M.; Costamagna, S.; Peeters, F.M. | ||||
Title | Thermomechanical properties of a single hexagonal boron nitride sheet | Type | A1 Journal article | ||
Year | 2013 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 87 | Issue | 18 | Pages | 184106-184107 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Using atomistic simulations we investigate the thermodynamical properties of a single atomic layer of hexagonal boron nitride (h-BN). The thermal induced ripples, heat capacity, and thermal lattice expansion of large scale h-BN sheets are determined and compared to those found for graphene (GE) for temperatures up to 1000 K. By analyzing the mean-square height fluctuations < h(2)> and the height-height correlation function H(q) we found that the h-BN sheet is a less stiff material as compared to graphene. The bending rigidity of h-BN (i) is about 16% smaller than the one of GE at room temperature (300 K), and (ii) increases with temperature as in GE. The difference in stiffness between h-BN and GE results in unequal responses to external uniaxial and shear stress and different buckling transitions. In contrast to a GE sheet, the buckling transition of a h-BN sheet depends strongly on the direction of the applied compression. The molar heat capacity, thermal-expansion coefficient, and Gruneisen parameter are estimated to be 25.2 J mol(-1) K-1, 7.2 x 10(-6) K-1, and 0.89, respectively. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000318653800001 | Publication Date | 2013-05-08 | |
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 | 80 | Open Access | |
Notes | ; We thank K. H. Michel and D. A. Kirilenko for their useful comments on the manuscript. M. N.-A. was supported by EU-Marie Curie IIF Postdoctorate Fellowship No. 299855. S. Costamagna was supported by the Belgian Science Foundation (BELSPO). This work was supported by the ESF-EuroGRAPHENE project CONGRAN, the Flemish Science Foundation (FWO-Vl), and the Methusalem program of the Flemish Government. ; | Approved | Most recent IF: 3.836; 2013 IF: 3.664 | ||
Call Number | UA @ lucian @ c:irua:109010 | Serial | 3638 | ||
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Author | Muñoz, W.A.; Covaci, L.; Peeters, F.M. | ||||
Title | Superconducting current and proximity effect in ABA and ABC multilayer graphene Josephson junctions | Type | A1 Journal article | ||
Year | 2013 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 88 | Issue | 88 | Pages | 214502 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Using a numerical tight-binding approach based on the Chebyshev–Bogoliubov–de Gennes method we describe Josephson junctions made of multilayer graphene contacted by top superconducting gates. Both Bernal (ABA) and rhombohedral (ABC) stacking are considered and we find that the type of stacking has a strong effect on the proximity effect and the supercurrent flow. For both cases the pair amplitude shows a polarization between dimer and nondimer atoms, being more pronounced for rhombohedral stacking. Even though the proximity effect in nondimer sites is enhanced when compared to single-layer graphene, we find that the supercurrent is suppressed. The spatial distribution of the supercurrent shows that for Bernal stacking the current flows only in the topmost layers while for rhombohedral stacking the current flows throughout the whole structure. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000328569900004 | Publication Date | 2013-12-02 | |
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 | 4 | Open Access | |
Notes | This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem funding of the Flemish Government | Approved | Most recent IF: 3.836; 2013 IF: 3.664 | ||
Call Number | CMT @ cmt @ c:irua:128896 | Serial | 3962 | ||
Permanent link to this record | |||||
Author | Stefaniak, E.A.; Darchuk, L.; Sapundjiev, D.; Kips, R.; Aregbe, Y.; Van Grieken, R. | ||||
Title | New insight into UO2F2 particulate structure by micro-Raman spectroscopy | Type | A1 Journal article | ||
Year | 2013 | Publication | Journal of molecular structure | Abbreviated Journal | |
Volume | 1040 | Issue | Pages | 206-212 | |
Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
Abstract | Uranyl fluoride particles produced via hydrolysis of uranium hexafluoride have been deposited on different substrates: polished graphite disks, silver foil, stainless steel and gold-coated silicon wafer, and measured with micro-Raman spectroscopy (MRS). All three metallic substrates enhanced the Raman signal delivered by UO2F2 in comparison to graphite. The fundamental stretching of the UO band appeared at 867 cm−1 in case of the graphite substrate, while in case of the others it was shifted to lower frequencies (down to 839 cm−1). All applied metallic substrates showed the expected effect of Raman signal enhancement; however the gold layer appeared to be most effective. Application of new substrates provides more information on the molecular structure of uranyl fluoride precipitation, which is interesting for nuclear safeguards and nuclear environmental analysis. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000318961000027 | Publication Date | 2013-02-19 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0022-2860 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | Times cited | Open Access | |||
Notes | Approved | no | |||
Call Number | UA @ admin @ c:irua:107123 | Serial | 8299 | ||
Permanent link to this record | |||||
Author | Hauchecorne, B.; Lenaerts, S. | ||||
Title | Unravelling the mysteries of gas phase photocatalytic reaction pathways by studying the catalyst surface : a literature review of different Fourier transform infrared spectroscopic reaction cells used in the field | Type | A1 Journal article | ||
Year | 2013 | Publication | Journal of photochemistry and photobiology: C: photochemistry reviews | Abbreviated Journal | J Photoch Photobio C |
Volume | 14 | Issue | Pages | 72-85 | |
Keywords | A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) | ||||
Abstract | Unlike the profound knowledge of the reaction mechanisms occurring in water phase photocatalysis, still fairly little is known on the reaction mechanisms occurring on the catalyst surface when dealing with gaseous pollutants. Unfortunately, there are some differences between both reactions. For one, there are no abundant hydroxyl radicals present in the gas phase, so that possibly other species prove to be important in abating the pollutant. In order to unravel the mysteries of gas phase photocatalytic reaction pathways, in situ techniques must be used to allow the detection and identification of reaction intermediates on a working catalyst. Several techniques were already used in the past, of which Fourier transform infrared spectroscopy seems to be the most versatile. This review will therefore give a selective overview of different spectroscopic reaction cells constructed for the in situ study of photocatalytic gas phase reactions. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000314669600005 | Publication Date | 2012-09-28 | |
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ISSN | 1389-5567 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 12.317 | Times cited | 8 | Open Access | |
Notes | ; The University of Antwerp is greatly acknowledged for the fellowship granted to Birger Hauchecorne. The authors would also like to thank Sammy W. Verbruggen for his help in providing several papers of interest. ; | Approved | Most recent IF: 12.317; 2013 IF: 11.625 | ||
Call Number | UA @ admin @ c:irua:106518 | Serial | 6001 | ||
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Author | Sahin, H.; Tongay, S.; Horzum, S.; Fan, W.; Zhou, J.; Li, J.; Wu, J.; Peeters, F.M. | ||||
Title | Anomalous Raman spectra and thickness-dependent electronic properties of WSe2 | Type | A1 Journal article | ||
Year | 2013 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 87 | Issue | 16 | Pages | 165409-6 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Typical Raman spectra of transition-metal dichalcogenides (TMDs) display two prominent peaks, E-2g and A(1g), that are well separated from each other. We find that these modes are degenerate in bulk WSe2 yielding one single Raman peak in contrast to other TMDs. As the dimensionality is lowered, the observed peak splits in two. In contrast, our ab initio calculations predict that the degeneracy is retained even for WSe2 monolayers. Interestingly, for minuscule biaxial strain, the degeneracy is preserved, but once the crystal symmetry is broken by a small uniaxial strain, the degeneracy is lifted. Our calculated phonon dispersion for uniaxially strained WSe2 shows a good match to the measured Raman spectrum, which suggests that uniaxial strain exists in WSe2 flakes, possibly induced during the sample preparation and/or as a result of the interaction between WSe2 and the substrate. Furthermore, we find that WSe2 undergoes an indirect-to-direct band-gap transition from bulk to monolayers, which is ubiquitous for semiconducting TMDs. These results not only allow us to understand the vibrational and electronic properties of WSe2, but also point to effects of the interaction between the monolayer TMDs and the substrate on the vibrational and electronic properties. DOI: 10.1103/PhysRevB.87.165409 | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000317195400007 | Publication Date | 2013-04-05 | |
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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 | 365 | Open Access | |
Notes | ; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem programme of the Flemish government. Computational resources were partially provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). H. S. is supported by the FWO Pegasus Marie Curie Long Fellowship program. ; | Approved | Most recent IF: 3.836; 2013 IF: 3.664 | ||
Call Number | UA @ lucian @ c:irua:108471 | Serial | 134 | ||
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