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Author Tan, H.; Egoavil, R.; Béché, A.; Martinez, G.T.; Van Aert, S.; Verbeeck, J.; Van Tendeloo, G.; Rotella, H.; Boullay, P.; Pautrat, A.; Prellier, W.
  Title Mapping electronic reconstruction at the metal-insulator interface in LaVO3/SrVO3 heterostructures Type A1 Journal article
  Year (down) 2013 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 88 Issue 15 Pages 155123-155126
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract A (LaVO3)6/(SrVO3)(3) superlattice is studied with a combination of sub-A resolved scanning transmission electron microscopy and monochromated electron energy-loss spectroscopy. The V oxidation state is mapped with atomic spatial resolution enabling us to investigate electronic reconstruction at the LaVO3/SrVO3 interfaces. Surprisingly, asymmetric charge distribution is found at adjacent chemically symmetric interfaces. The local structure is proposed and simulated with a double channeling calculation which agrees qualitatively with our experiment. We demonstrate that local strain asymmetry is the likely cause of the electronic asymmetry of the interfaces. The electronic reconstruction at the interfaces extends much further than the chemical composition, varying from 0.5 to 1.2 nm. This distance corresponds to the length of charge transfer previously found in the (LaVO3)./(SrVO3). metal/insulating and the (LaAlO3)./(SrTiO3). insulating/insulating interfaces.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000326087100003 Publication Date 2013-10-21
  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 15 Open Access
  Notes Hercules; 246791 COUNTATOMS; 278510 VORTEX; 246102 IFOX; 312483 ESTEEM2; FWO; GOA XANES meets ELNES; esteem2jra3 ECASJO; Approved Most recent IF: 3.836; 2013 IF: 3.664
  Call Number UA @ lucian @ c:irua:112733UA @ admin @ c:irua:112733 Serial 1944
Permanent link to this record
 

 
Author Singh, S.K.; Neek-Amal, M.; Peeters, F.M.
  Title Melting of graphene clusters Type A1 Journal article
  Year (down) 2013 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 87 Issue 13 Pages 134103-134109
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract Density-functional tight-binding and classical molecular dynamics simulations are used to investigate the structural deformations and melting of planar carbon nanoclusters C-N with N = 2-55. The minimum-energy configurations for different clusters are used as starting configurations for the study of the temperature effects on the bond breaking and rotation in carbon lines (N < 6), carbon rings (5 < N < 19), and graphene nanoflakes. The larger the rings (graphene nanoflakes) the higher the transition temperature (melting point) with ring-to-line (perfect-to-defective) transition structures. The melting point was obtained by using the bond energy, the Lindemann criteria, and the specific heat. We found that hydrogen-passivated graphene nanoflakes (CNHM) have a larger melting temperature with a much smaller dependence on size. The edges in the graphene nanoflakes exhibit several different metastable configurations (isomers) during heating before melting occurs. DOI: 10.1103/PhysRevB.87.134103
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000317390700001 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 28 Open Access
  Notes ; This work was supported by the EU-Marie Curie IIF Postdoctoral Fellowship No. 299855 (for M.N.-A.), the ESF-EuroGRAPHENE Project CONGRAN, the Flemish Science Foundation (FWO-Vl), and the Methusalem Foundation of the Flemish Government. ; Approved Most recent IF: 3.836; 2013 IF: 3.664
  Call Number UA @ lucian @ c:irua:108467 Serial 1987
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Author Peirs, J.; Tirry, W.; Amin-Ahmadi, B.; Coghe, F.; Verleysen, P.; Rabet, L.; Schryvers, D.; Degrieck, J.
  Title Microstructure of adiabatic shear bands in Ti6Al4V Type A1 Journal article
  Year (down) 2013 Publication Materials characterization Abbreviated Journal Mater Charact
  Volume 75 Issue Pages 79-92
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract Microstructural deformation mechanisms in adiabatic shear bands in Ti6Al4V are studied using traditional TEM and selected area diffraction, and more advanced microstructural characterisation techniques such as energy dispersive X-ray spectroscopy, high angle annular dark field STEM and conical dark field TEM. The shear bands under investigation are induced in Ti6Al4V samples by high strain rate compression of cylindrical and hat-shaped specimens in a split Hopkinson pressure bar setup. Samples from experiments interrupted at different levels of deformation are used to study the evolution of the microstructure in and nearby the shear bands. From the early stages of adiabatic shear band formation, TEM revealed strongly elongated equiaxed grains in the shear band. These band-like grains become narrower towards the centre of the band and start to fraction even further along their elongated direction to finally result in a nano-crystalline region in the core. In fully developed shear bands, twins and a needle-like martensite morphology are observed near the shear band.
  Address
  Corporate Author Thesis
  Publisher Place of Publication New York Editor
  Language Wos 000314860900011 Publication Date 2012-11-07
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1044-5803; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 2.714 Times cited 56 Open Access
  Notes Iuap; Fwo Approved Most recent IF: 2.714; 2013 IF: 1.925
  Call Number UA @ lucian @ c:irua:105300 Serial 2065
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Author Van Duppen, B.; Sena, S.H.R.; Peeters, F.M.
  Title Multiband tunneling in trilayer graphene Type A1 Journal article
  Year (down) 2013 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 87 Issue 19 Pages 195439-10
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract The electronic tunneling properties of the two stable forms of trilayer graphene (TLG), rhombohedral ABC and Bernal ABA, are examined for p-n and p-n-p junctions as realized by using a single gate (SG) or a double gate (DG). For the rhombohedral form, due to the chirality of the electrons, the Klein paradox is found at normal incidence for SG devices, while at high-energy interband scattering between additional propagation modes can occur. The electrons in Bernal ABA TLG can have a monolayer- or bilayer-like character when incident on a SG device. Using a DG, however, both propagation modes will couple by breaking the mirror symmetry of the system, which induces intermode scattering and resonances that depend on the width of the DG p-n-p junction. For ABC TLG the DG opens up a band gap which suppresses Klein tunneling. The DG induces also an unexpected asymmetry in the tunneling angle for single-valley electrons.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000319281700004 Publication Date 2013-05-23
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 3.836 Times cited 13 Open Access
  Notes ; This work was supported by the European Science Foundation (ESF) under the EUROCORES Program EuroGRAPHENE within the project CONGRAN, the Flemish Science Foundation (FWO-VI) by an aspirant research grant to B. Van Duppen and the Methusalem Programme of the Flemish Government. ; Approved Most recent IF: 3.836; 2013 IF: 3.664
  Call Number UA @ lucian @ c:irua:108998 Serial 2216
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Author Schryvers, D.; Shi, H.; Martinez, G.T.; Van Aert, S.; Frenzel, J.; Van Humbeeck, J.
  Title Nano- and microcrystal investigations of precipitates, interfaces and strain fields in Ni-Ti-Nb by various TEM techniques Type P1 Proceeding
  Year (down) 2013 Publication Materials science forum T2 – 9th European Symposium on Martensitic Transformations (ESOMAT 2012), SEP 09-16, 2012, St Petersburg, RUSSIA Abbreviated Journal
  Volume 738/739 Issue Pages 65-71
  Keywords P1 Proceeding; Electron microscopy for materials research (EMAT)
  Abstract In the present contribution several advanced electron microscopy techniques are employed in order to describe chemical and structural features of the nano- and microstructure of a Ni45.5Ti45.5Nb9 alloy. A line-up of Nb-rich nano-precipitates is found in the Ni-Ti-rich austenite of as-cast material. Concentration changes of the matrix after annealing are correlated with changes in the transformation temperatures. The formation of rows and plates of larger Nb-rich precipitates and particles is described. The interaction of a twinned martensite plate with a Nb-rich nano-precipitate is discussed and the substitution of Nb atoms on the Ti-sublattice in the matrix is confirmed.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Lausanne Editor
  Language Wos 000316089000011 Publication Date 2013-03-11
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1662-9752; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor Times cited 2 Open Access
  Notes Fwo Approved Most recent IF: NA
  Call Number UA @ lucian @ c:irua:104692 Serial 2247
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Author Khalilov, U.; Pourtois, G.; Huygh, S.; van Duin, A.C.T.; Neyts, E.C.; Bogaerts, A.
  Title New mechanism for oxidation of native silicon oxide Type A1 Journal article
  Year (down) 2013 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
  Volume 117 Issue 19 Pages 9819-9825
  Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
  Abstract Continued miniaturization of metal-oxide-semiconductor field-effect transistors (MOSFETs) requires an ever-decreasing thickness of the gate oxide. The structure of ultrathin silicon oxide films, however, critically depends on the oxidation mechanism. Using reactive atomistic simulations, we here demonstrate how the oxidation mechanism in hyperthermal oxidation of such structures may be controlled by the oxidation temperature and the oxidant energy. Specifically, we study the interaction of hyperthermal oxygen with energies of 15 eV with thin SiOx (x ≤ 2) films with a native oxide thickness of about 10 Å. We analyze the oxygen penetration depth probability and compare with results of the hyperthermal oxidation of a bare Si(100){2 × 1} (c-Si) surface. The temperature-dependent oxidation mechanisms are discussed in detail. Our results demonstrate that, at low (i.e., room) temperature, the penetrated oxygen mostly resides in the oxide region rather than at the SiOx|c-Si interface. However, at higher temperatures, starting at around 700 K, oxygen atoms are found to penetrate and to diffuse through the oxide layer followed by reaction at the c-Si boundary. We demonstrate that hyperthermal oxidation resembles thermal oxidation, which can be described by the DealGrove model at high temperatures. Furthermore, defect creation mechanisms that occur during the oxidation process are also analyzed. This study is useful for the fabrication of ultrathin silicon oxide gate oxides for metal-oxide-semiconductor devices as it links parameters that can be straightforwardly controlled in experiment (oxygen temperature, velocity) with the silicon oxide structure.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Washington, D.C. Editor
  Language Wos 000319649100032 Publication Date 2013-04-23
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1932-7447;1932-7455; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 4.536 Times cited 24 Open Access
  Notes Approved Most recent IF: 4.536; 2013 IF: 4.835
  Call Number UA @ lucian @ c:irua:107989 Serial 2321
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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 (down) 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.
  Address
  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
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Author Horzum, S.; Sahin, H.; Cahangirov, S.; Cudazzo, P.; Rubio, A.; Serin, T.; Peeters, F.M.
  Title Phonon softening and direct to indirect band gap crossover in strained single-layer MoSe2 Type A1 Journal article
  Year (down) 2013 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 87 Issue 12 Pages 125415-5
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract Motivated by recent experimental observations of Tongay et al. [Nano Lett. 12, 5576 (2012)] we show how the electronic properties and Raman characteristics of single layer MoSe2 are affected by elastic biaxial strain. We found that with increasing strain: (1) the E' and E '' Raman peaks (E-2g and E-1g in bulk) exhibit significant redshifts (up to similar to 30 cm(-1)), (2) the position of the A'(1) peak remains at similar to 180 cm(-1) (A(1g) in bulk) and does not change considerably with further strain, (3) the dispersion of low energy flexural phonons crosses over from quadratic to linear, and (4) the electronic band structure undergoes a direct to indirect band gap crossover under similar to 3% biaxial tensile strain. Thus the application of strain appears to be a promising approach for a rapid and reversible tuning of the electronic, vibrational, and optical properties of single layer MoSe2 and similar MX2 dichalcogenides. DOI:10.1103/PhysRevB.87.125415
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000316383700006 Publication Date 2013-03-14
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 3.836 Times cited 171 Open Access
  Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem programme of the Flemish government. Computational resources were partially provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). H.S. is supported by a FWO Pegasus Marie Curie Long Fellowship. ; Approved Most recent IF: 3.836; 2013 IF: 3.664
  Call Number UA @ lucian @ c:irua:108277 Serial 2605
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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.
  Title Photoconductivity of nanocrystalline SnO2 sensitized with colloidal CdSe quantum dots Type A1 Journal article
  Year (down) 2013 Publication Journal of materials chemistry C : materials for optical and electronic devices Abbreviated Journal J Mater Chem C
  Volume 1 Issue 5 Pages 1005-1010
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  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.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000314803600016 Publication Date 2012-11-14
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 2050-7526;2050-7534; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 5.256 Times cited 13 Open Access
  Notes Approved Most recent IF: 5.256; 2013 IF: NA
  Call Number UA @ lucian @ c:irua:107705 Serial 2610
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Author Zhang, S.H.; Xu, W.; Badalyan, S.M.; Peeters, F.M.
  Title Piezoelectric surface acoustical phonon limited mobility of electrons in graphene on a GaAs substrate Type A1 Journal article
  Year (down) 2013 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 87 Issue 7 Pages 075443-75445
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract We study the mobility of Dirac fermions in monolayer graphene on a GaAs substrate, limited by the combined action of the extrinsic potential of piezoelectric surface acoustical phonons of GaAs (PA) and of the intrinsic deformation potential of acoustical phonons in graphene (DA). In the high-temperature (T) regime, the momentum relaxation rate exhibits the same linear dependence on T but different dependencies on the carrier density n, corresponding to the mobility mu proportional to 1 root n and 1/n, respectively for the PA and DA scattering mechanisms. In the low-T Bloch-Gruneisen regime, the mobility shows the same square-root density dependence mu proportional to root n, but different temperature dependencies mu proportional to T-3 and T-4, respectively for PA and DA phonon scattering. DOI: 10.1103/PhysRevB.87.075443
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000315375200008 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 25 Open Access
  Notes ; This work was supported by the ESF-Eurocores program EuroGRAPHENE (CONGRAN project) and the Flemish Science Foundation (FWO-VI). ; Approved Most recent IF: 3.836; 2013 IF: 3.664
  Call Number UA @ lucian @ c:irua:107655 Serial 2622
Permanent link to this record
 

 
Author Snoeckx, R.; Aerts, R.; Tu, X.; Bogaerts, A.
  Title Plasma-based dry reforming : a computational study ranging from the nanoseconds to seconds time scale Type A1 Journal article
  Year (down) 2013 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
  Volume 117 Issue 10 Pages 4957-4970
  Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
  Abstract We present a computational study for the conversion of CH4 and CO2 into value-added chemicals, i.e., the so-called dry reforming of methane, in a dielectric barrier discharge reactor. A zero-dimensional chemical kinetics model is applied to study the plasma chemistry in a 1:1 CH4/CO2 mixture. The calculations are first performed for one microdischarge pulse and its afterglow, to study in detail the chemical pathways of the conversion. Subsequently, long time-scale simulations are carried out, corresponding to real residence times in the plasma, assuming a large number of consecutive microdischarge pulses, to mimic the conditions of the filamentary discharge regime in a dielectric barrier discharge (DBD) reactor. The conversion of CH4 and CO2 as well as the selectivity of the formed products and the energy cost and energy efficiency of the process are calculated and compared to experiments for a range of different powers and gas flows, and reasonable agreement is reached.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Washington, D.C. Editor
  Language Wos 000316308400010 Publication Date 2013-02-18
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1932-7447;1932-7455; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 4.536 Times cited 118 Open Access
  Notes Approved Most recent IF: 4.536; 2013 IF: 4.835
  Call Number UA @ lucian @ c:irua:106516 Serial 2628
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Author Yusupov, M.; Bogaerts, A.; Huygh, S.; Snoeckx, R.; van Duin, A.C.T.; Neyts, E.C.
  Title Plasma-induced destruction of bacterial cell wall components : a reactive molecular dynamics simulation Type A1 Journal article
  Year (down) 2013 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
  Volume 117 Issue 11 Pages 5993-5998
  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.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Washington, D.C. Editor
  Language Wos 000316773000056 Publication Date 2013-02-23
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1932-7447;1932-7455; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 4.536 Times cited 59 Open Access
  Notes Approved Most recent IF: 4.536; 2013 IF: 4.835
  Call Number UA @ lucian @ c:irua:107154 Serial 2636
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Author Zhu, J.-J.; Badalyan, S.M.; Peeters, F.M.
  Title Plasmonic excitations in Coulomb-coupled N-layer graphene structures Type A1 Journal article
  Year (down) 2013 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 87 Issue 8 Pages 085401-85408
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract We study Dirac plasmons and their damping in spatially separated N-layer graphene structures at finite doping and temperatures. The plasmon spectrum consists of one optical excitation with square-root dispersion and N – 1 acoustical excitations with linear dispersion, which are undamped at zero temperature and finite doping within a triangular energy region outside the electron-hole continuum. In the long-wavelength limit the energy and weight of the optical plasmon modes increase, respectively, as the square root and linearly with N in agreement with recent experimental findings. The energy and weight of the upper-lying acoustical branches also increase with N. This increase is strongest for the uppermost acoustical mode, and we find that its energy can exceed at some value of momentum the plasmon energy in an individual graphene sheet. Meanwhile, the energy of the low-lying acoustical branches decreases weakly with N as compared with the single acoustical mode in double-layer graphene structures. Our numerical calculations provide a detailed understanding of the overall behavior of the wave-vector dependence of the optical and acoustical multilayer plasmon modes and show how their dispersion and damping are modified as a function of temperature, interlayer spacing, and inlayer carrier density in (un)balanced graphene multilayer structures. DOI: 10.1103/PhysRevB.87.085401
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000314682900005 Publication Date 2013-02-05
  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 59 Open Access
  Notes ; This work was supported by the ESF-Eurocores program EuroGRAPHENE (CONGRAN project) and the Flemish Science Foundation (FWO-Vl). ; Approved Most recent IF: 3.836; 2013 IF: 3.664
  Call Number UA @ lucian @ c:irua:107671 Serial 2645
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Author Van Aert, S.; de Backer, A.; Martinez, G.T.; Goris, B.; Bals, S.; Van Tendeloo, G.; Rosenauer, A.
  Title Procedure to count atoms with trustworthy single-atom sensitivity Type A1 Journal article
  Year (down) 2013 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 87 Issue 6 Pages 064107-6
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract We report a method to reliably count the number of atoms from high-angle annular dark field scanning transmission electron microscopy images. A model-based analysis of the experimental images is used to measure scattering cross sections at the atomic level. The high sensitivity of these measurements in combination with a thorough statistical analysis enables us to count atoms with single-atom sensitivity. The validity of the results is confirmed by means of detailed image simulations. We will show that the method can be applied to nanocrystals of arbitrary shape, size, and atom type without the need for a priori knowledge about the atomic structure.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000315144700006 Publication Date 2013-02-20
  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 106 Open Access
  Notes FWO; 262348 ESMI; 312483 ESTEEM2;246791 COUNTATOMS; Hercules 3; esteem2_jra2 Approved Most recent IF: 3.836; 2013 IF: 3.664
  Call Number UA @ lucian @ c:irua:105674 Serial 2718
Permanent link to this record
 

 
Author Spreitzer, M.; Egoavil, R.; Verbeeck, J.; Blank, D.H.A.; Rijnders, G.
  Title Pulsed laser deposition of SrTiO3 on a H-terminated Si substrate Type A1 Journal article
  Year (down) 2013 Publication Journal of materials chemistry C : materials for optical and electronic devices Abbreviated Journal J Mater Chem C
  Volume 1 Issue 34 Pages 5216-5222
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract Interfacing oxides with silicon is a long-standing problem related to the integration of multifunctional oxides with semiconductor devices and the replacement of SiO2 with high-k gate oxides. In our study, pulsed laser deposition was used to prepare a SrTiO3 (STO) thin film on a H-terminated Si substrate. The main purpose of our work was to verify the ability of H-termination against the oxidation of Si during the PLD process and to analyze the resulting interfaces. In the first part of the study, the STO was deposited directly on the Si, leading to the formation of a preferentially textured STO film with a (100) orientation. In the second part, SrO was used as a buffer layer, which enabled the partial epitaxial growth of STO with STO(110)parallel to Si(100) and STO[001]parallel to Si[001]. The change in the growth direction induced by the application of a SrO buffer was governed by the formation of a SrO(111) intermediate layer and subsequently by the minimization of the lattice misfit between the STO and the SrO. Under the investigated conditions, approximately 10 nm thick interfacial layers formed between the STO and the Si due to reactions between the deposited material and the underlying H-terminated Si. In the case of direct STO deposition, SiOx formed at the interface with the silicon, while in the case when SrO was used as a buffer, strontium silicate grew directly on the silicon, which improves the growth quality of the uppermost STO.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000322911900005 Publication Date 2013-07-12
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 2050-7526;2050-7534; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 5.256 Times cited 23 Open Access
  Notes Ifox; Esteem2; Vortex; Countatoms; esteem2jra3 ECASJO; Approved Most recent IF: 5.256; 2013 IF: NA
  Call Number UA @ lucian @ c:irua:110798UA @ admin @ c:irua:110798 Serial 2739
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Author Marikutsa, A.V.; Rumyantseva, M.N.; Frolov, D.D.; Morozov, I.V.; Boltalin, A.I.; Fedorova, A.A.; Petukhov, I.A.; Yashina, L.V.; Konstantinova, E.A.; Sadovskaya, E.M.; Abakumov, A.M.; Zubavichus, Y.V.; Gaskov, A.M.;
  Title Role of PdOx and RuOy clusters in oxygen exchange between nanocrystalline tin dioxide and the gas phase Type A1 Journal article
  Year (down) 2013 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
  Volume 117 Issue 45 Pages 23858-23867
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
  Abstract The effect of palladium- and ruthenium-based clusters on nanocrystalline tin dioxide interaction with oxygen was studied by temperature-programmed oxygen isotopic exchange with mass-spectrometry detection. The modification of aqueous sol-gel prepared SnO2 by palladium and, to a larger extent, by ruthenium, increases surface oxygen concentration on the materials. The revealed effects on oxygen exchange-lowering the threshold temperature, separation of surface oxygen contribution to the process, increase of heteroexchange rate and oxygen diffusion coefficient, decrease of activation energies of exchange and diffusion-were more intensive for Ru-modified SnO2 than in the case of SnO2/Pd. The superior promoting activity of ruthenium on tin dioxide interaction with oxygen was interpreted by favoring the dissociative O-2 adsorption and increasing the oxygen mobility, taking into account the structure and chemical composition of the modifier clusters.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Washington, D.C. Editor
  Language Wos 000327110500046 Publication Date 2013-10-04
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1932-7447;1932-7455; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 4.536 Times cited 20 Open Access
  Notes Approved Most recent IF: 4.536; 2013 IF: 4.835
  Call Number UA @ lucian @ c:irua:112706 Serial 2924
Permanent link to this record
 

 
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 (down) 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
  Address
  Corporate Author Thesis
  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 Komendová, L.; Milošević, M.V.; Peeters, F.M.
  Title Soft vortex matter in a type-I/type-II superconducting bilayer Type A1 Journal article
  Year (down) 2013 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 88 Issue 9 Pages 094515
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract Magnetic flux patterns are known to strongly differ in the intermediate state of type-I and type-II superconductors. Using a type-I/type-II bilayer we demonstrate hybridization of these flux phases into a plethora of unique new ones. Owing to a complicated multibody interaction between individual fluxoids, many different intriguing patterns are possible under applied magnetic field, such as few-vortex clusters, vortex chains, mazes, or labyrinthal structures resembling the phenomena readily encountered in soft-matter physics. However, in our system the patterns are tunable by sample parameters, magnetic field, current, and temperature, which reveals transitions from short-range clustering to long-range ordered phases such as parallel chains, gels, glasses, and crystalline vortex lattices, or phases where lamellar type-I flux domains in one layer serve as a bedding potential for type-II vortices in the other, configurations clearly beyond the soft-matter analogy.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000324689900008 Publication Date 2013-09-24
  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 27 Open Access
  Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl). Insightful discussions with Arkady Shanenko and Edith Cristina Euan Diaz are gratefully acknowledged. ; Approved Most recent IF: 3.836; 2013 IF: 3.664
  Call Number UA @ lucian @ c:irua:111167 Serial 3050
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Author Badalyan, S.M.; Matos-Abiague, A.; Fabian, J.; Vignale, G.; Peeters, F.M.
  Title Spin-orbit-interaction induced singularity of the charge density relaxation propagator Type A1 Journal article
  Year (down) 2013 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 88 Issue 19 Pages 195402-195405
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract The charge density relaxation propagator of a two-dimensional electron system, which is the slope of the imaginary part of the polarization function, exhibits singularities for bosonic momenta having the order of the spin-orbit momentum and depending on the momentum orientation. We have provided an intuitive understanding for this nonanalytic behavior in terms of the interchirality subband electronic transitions, induced by the combined action of Bychkov-Rashba (BR) and Dresselhaus (D) spin-orbit coupling. It is shown that the regular behavior of the relaxation propagator is recovered in the presence of only one BR or D spin-orbit field or for spin-orbit interaction with equal BR and D coupling strengths. This creates a new possibility to influence carrier relaxation properties by means of an applied electric field.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000326820200005 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 2 Open Access
  Notes ; We acknowledge support from the Methusalem program of the Flemish government and the Flemish Science Foundation (FWO-Vl), DFG SFB Grant 689, and NSF Grant DMR-1104788 (G.V.). ; Approved Most recent IF: 3.836; 2013 IF: 3.664
  Call Number UA @ lucian @ c:irua:112711 Serial 3093
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Author Neek-Amal, M.; Beheshtian, J.; Shayeganfar, F.; Singh, S.K.; Los, J.H.; Peeters, F.M.
  Title Spiral graphone and one-sided fluorographene nanoribbons Type A1 Journal article
  Year (down) 2013 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 87 Issue 7 Pages 075448-8
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract The instability of a free-standing one-sided hydrogenated/fluorinated graphene nanoribbon, i.e., graphone/fluorographene, is studied using ab initio, semiempirical, and large-scale molecular dynamics simulations. Free-standing semi-infinite armchairlike hydrogenated/fluorinated graphene (AC-GH/AC-GF) and boatlike hydrogenated/fluorinated graphene (B-GH/B-GF) (nanoribbons which are periodic along the zigzag direction) are unstable and spontaneously transform into spiral structures. We find that rolled, spiral B-GH and B-GF are energetically more favorable than spiral AC-GH and AC-GF which is opposite to the double-sided flat hydrogenated/fluorinated graphene, i.e., graphane/fluorographene. We found that the packed, spiral structures exhibit an unexpected localized highest occupied molecular orbital and lowest occupied molecular orbital at the edges with increasing energy gap during rolling. These rolled hydrocarbon structures are stable beyond room temperature up to at least T = 1000 K within our simulation time of 1 ns. DOI: 10.1103/PhysRevB.87.075448
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000315481800005 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 14 Open Access
  Notes ; We thank A. Sadeghi, M. R. Ejtehadi, and J. Amini for their useful comments. This work is supported by the ESF EuroGRAPHENE project CONGRAN and the Flemish Science Foundation (FWO-Vl). M.N.-A. is supported by a EU-Marie Curie IIF fellowship program Grant No. 299855. ; Approved Most recent IF: 3.836; 2013 IF: 3.664
  Call Number UA @ lucian @ c:irua:107654 Serial 3106
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Author Sahin, H.; Sivek, J.; Li, S.; Partoens, B.; Peeters, F.M.
  Title Stone-Wales defects in silicene : formation, stability, and reactivity of defect sites Type A1 Journal article
  Year (down) 2013 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 88 Issue 4 Pages 045434-45436
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract During the synthesis of ultrathin materials with hexagonal lattice structure Stone-Wales (SW) type of defects are quite likely to be formed and the existence of such topological defects in the graphenelike structures results in dramatic changes of their electronic and mechanical properties. Here we investigate the formation and reactivity of such SW defects in silicene. We report the energy barrier for the formation of SW defects in freestanding (similar to 2.4 eV) and Ag(111)-supported (similar to 2.8 eV) silicene and found it to be significantly lower than in graphene (similar to 9.2 eV). Moreover, the buckled nature of silicene provides a large energy barrier for the healing of the SW defect and therefore defective silicene is stable even at high temperatures. Silicene with SW defects is semiconducting with a direct band gap of 0.02 eV and this value depends on the concentration of defects. Furthermore, nitrogen substitution in SW-defected silicene shows that the defect lattice sites are the least preferable substitution locations for the N atoms. Our findings show the easy formation of SW defects in silicene and also provide a guideline for band gap engineering in silicene-based materials through such defects.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000322113300007 Publication Date 2013-07-23
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 3.836 Times cited 93 Open Access
  Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem foundation of the Flemish government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure), and HPC infrastructure of the University of Antwerp (CalcUA) a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation. H.S. is supported by a FWO Pegasus Marie Curie Fellowship. ; Approved Most recent IF: 3.836; 2013 IF: 3.664
  Call Number UA @ lucian @ c:irua:109805 Serial 3162
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Author Arsoski, V.V.; Tadić, M.Z.; Peeters, F.M.
  Title Strain and band-mixing effects on the excitonic Aharonov-Bohm effect in In(Ga)As/GaAs ringlike quantum dots Type A1 Journal article
  Year (down) 2013 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 87 Issue 8 Pages 085314-14
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract Neutral excitons in strained axially symmetric In(Ga)As/GaAs quantum dots with a ringlike shape are investigated. Similar to experimental self-assembled quantum rings, the analyzed quantum dots have volcano-like shapes. The continuum mechanical model is employed to determine the strain distribution, and the single-band envelope function approach is adopted to compute the electron states. The hole states are determined by the axially symmetric multiband Luttinger-Kohn Hamiltonian, and the exciton states are obtained from an exact diagonalization. We found that the presence of the inner layer covering the ring opening enhances the excitonic Aharonov-Bohm (AB) oscillations. The reason is that the hole becomes mainly localized in the inner part of the quantum dot due to strain, whereas the electron resides mainly inside the ring-shaped rim. Interestingly, larger AB oscillations are found in the analyzed quantum dot than in a fully opened quantum ring of the same width. Comparison with the unstrained ringlike quantum dot shows that the amplitude of the excitonic Aharonov-Bohm oscillations are almost doubled in the presence of strain. The computed oscillations of the exciton energy levels are comparable in magnitude to the oscillations measured in recent experiments. DOI: 10.1103/PhysRevB.87.085314
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000315278000003 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 18 Open Access
  Notes ; This work was supported by the EU NoE: SANDiE, the Ministry of Education, Science, and Technological Development of Serbia, and the Flemish Science Foundation (FWO-Vl). ; Approved Most recent IF: 3.836; 2013 IF: 3.664
  Call Number UA @ lucian @ c:irua:107656 Serial 3165
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Author Turner, S.; Lebedev, O.I.; Verbeeck, J.; Gehrke, K.; Moshnyaga, V.; Van Tendeloo, G.
  Title Structural phase transition and spontaneous interface reconstruction in La2/3Ca1/3MnO3/BaTiO3 superlattices Type A1 Journal article
  Year (down) 2013 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 87 Issue 3 Pages 035418-8
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract (La2/3Ca1/3MnO3)n/(BaTiO3)m (LCMOn/BTOm) superlattices on MgO and SrTiO3 substrates with different layer thicknesses (n = 10, 38, 40 and m = 5, 18, 20) have been grown by metal organic aerosol deposition (MAD) and have been fully characterized down to the atomic scale to study the interface characteristics. Scanning transmission electron microscopy combined with spatially resolved electron energy-loss spectroscopy provides clear evidence for the existence of atomically sharp interfaces in MAD grown films, which exhibit epitaxial growth conditions, a uniform normal strain, and a fully oxidized state. Below a critical layer thickness the LCMO structure is found to change from the bulk Pnma symmetry to a pseudocubic R3̅ c symmetry. An atomically flat interface reconstruction consisting of a single Ca-rich atomic layer is observed on the compressively strained BTO on LCMO interface, which is thought to partially neutralize the total charge from the alternating polar atomic layers in LCMO as well as relieving strain at the interface. No interface reconstruction is observed at the tensile strained LCMO on BTO interface.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000313940400008 Publication Date 2013-01-23
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 3.836 Times cited 12 Open Access
  Notes FWO; Hercules; Countatoms Approved Most recent IF: 3.836; 2013 IF: 3.664
  Call Number UA @ lucian @ c:irua:106180 Serial 3245
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Author Batuk, M.; Tyablikov, O.A.; Tsirlin, A.A.; Kazakov, S.M.; Rozova, M.G.; Pokholok, K.V.; Filimonov, D.S.; Antipov, E.V.; Abakumov, A.M.; Hadermann, J.
  Title Structure and magnetic properties of a new anion-deficient perovskite Pb2Ba2BiFe4ScO13 with crystallographic shear structure Type A1 Journal article
  Year (down) 2013 Publication Materials research bulletin Abbreviated Journal Mater Res Bull
  Volume 48 Issue 9 Pages 3459-3465
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract Pb2Ba2BiFe4ScO13, a new n = 5 member of the oxygen-deficient perovskite-based A(n)B(n)O(3n-2) homologous series, was synthesized using a solid-state method. The crystal structure of Pb2Ba2BiFe4ScO13 was investigated by a combination of synchrotron X-ray powder diffraction, electron diffraction, high-angle annular dark-field scanning transmission electron microscopy and Mossbauer spectroscopy. At 900 K, it crystallizes in the Ammm space group with the unit cell parameters a = 5.8459(1) angstrom, b = 4.0426(1) angstrom, and c=27.3435(1) angstrom. In the Pb2Ba2BiFe4ScO13 structure, quasi-two-dimensional perovskite blocks are periodically interleaved with 1/2[1 1 0] ((1) over bar 0 1)(p) crystallographic shear (CS) planes. At the CS planes, the corner-sharing FeO6 octahedra are transformed into chains of edge-sharing FeO5 distorted tetragonal pyramids. B-positions of the perovskite blocks between the CS planes are jointly occupied by Fe3+ and Sc3+. The chains of the FeO5 pyramids and (Fe,Sc)O-6 octahedra delimit six-sided tunnels that are occupied by double columns of cations with a lone electron pair (Pb2+). The remaining A-cations (Bi3+, Ba2+) occupy positions in the perovskite block. According to the magnetic susceptibility measurements, Pb2Ba2BiFe4ScO13 is antiferromagnetically ordered below T-N approximate to 350 K. (C) 2013 Elsevier Ltd. All rights reserved.
  Address
  Corporate Author Thesis
  Publisher Place of Publication New York, N.Y. Editor
  Language Wos 000322354000076 Publication Date 2013-05-17
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0025-5408; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 2.446 Times cited 2 Open Access
  Notes Approved Most recent IF: 2.446; 2013 IF: 1.968
  Call Number UA @ lucian @ c:irua:109756 Serial 3282
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Author Berdiyorov, G.R.; Savel'ev, S.E.; Milošević, M.V.; Kusmartsev, F.V.; Peeters, F.M.
  Title Synchronized dynamics of Josephson vortices in artificial stacks of SNS Josephson junctions under both dc and ac bias currents Type A1 Journal article
  Year (down) 2013 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 87 Issue 18 Pages 184510-184519
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract Nonlinear dynamics of Josephson vortices (fluxons) in artificial stacks of superconducting-normal-superconducting Josephson junctions under simultaneously applied time-periodic ac and constant biasing dc currents is studied using the time dependent Ginzburg-Landau formalism with a Lawrence-Doniach extension. At zero external magnetic field and dc biasing current the resistive state of the system is characterized by periodic nucleation and annihilation of fluxon-antifluxon pairs, relative positions of which are determined by the state of neighboring junctions. Due to the mutual repulsive interaction, fluxons in different junctions move out of phase. Their collective motion can be synchronized by adding a small ac component to the biasing dc current. Coherent motion of fluxons is observed for a broad frequency range of the applied drive. In the coherent state the maximal output voltage, which is proportional to the number of junctions in the stack, is observed near the characteristic frequency of the system determined by the crossing of the fluxons across the sample. However, in this frequency range the dynamically synchronized state has an alternative-a less ordered state with smaller amplitude of the output voltage. Collective behavior of the junctions is strongly affected by the sloped sidewalls of the stack. Synchronization is observed only for weakly trapezoidal cross sections, whereas irregular motion of fluxons is observed for larger slopes of the sample edge.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000319653400007 Publication Date 2013-05-28
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 3.836 Times cited 10 Open Access
  Notes ; This work was supported by the Flemish Science Foundation (FWO-VI) and by EU Marie Curie (Project No. 253057). ; Approved Most recent IF: 3.836; 2013 IF: 3.664
  Call Number UA @ lucian @ c:irua:109643 Serial 3406
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Author Retuerto, M.; Emge, T.; Hadermann, J.; Stephens, P.W.; Li, M.R.; Yin, Z.P.; Croft, M.; Ignatov, A.; Zhang, S.J.; Yuan, Z.; Jin, C.; Simonson, J.W.; Aronson, M.C.; Pan, A.; Basov, D.N.; Kotliar, G.; Greenblatt, M.;
  Title Synthesis and properties of charge-ordered thallium halide perovskites, CsTl0.5+Tl0.53+X3 (X = F or Cl) : theoretical precursors for superconductivity? Type A1 Journal article
  Year (down) 2013 Publication Chemistry of materials Abbreviated Journal Chem Mater
  Volume 25 Issue 20 Pages 4071-4079
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract Recently, CsTlCl3 and CsTlF3 perovskites were theoretically predicted to be potential superconductors if they were optimally doped. The syntheses of these two compounds together with a complete characterization of the samples are reported. CsTlCl3 was obtained as orange crystals in two different polymorphs: a tetragonal phase (I4/m) and a cubic phase (Fm (3) over barm). CsTlF3 was formed as a light brown powder, and also as a double cubic perovskite (Fm (3) over barm). In all three CsTlX3 phases, Tl+ and Tl3+ were located in two different crystallographic positions that accommodate their different bond lengths. In CsTlCl3, some Tl vacancies were found in the Tl+ position. The charge ordering between Tl+ and Tl3+ was confirmed by X-ray absorption and Raman spectroscopy. The Raman spectroscopy of CsTlCl3 at high pressure (58 GPa) did not indicate any phase transition to a possible single Tl2+ state. However, the highly insulating material became less resistive with an increasing high pressure, while it underwent a change in its optical properties, from transparent to deeply opaque red, indicative of a decrease in the magnitude of the band gap. The theoretical design and experimental validation of the existence of CsTlF3 and CsTlCl3 cubic perovskites are the necessary first steps in confirming the theoretical prediction of superconductivity in these materials.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Washington, D.C. Editor
  Language Wos 000326209200017 Publication Date 2013-09-18
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0897-4756;1520-5002; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 9.466 Times cited 28 Open Access
  Notes Approved Most recent IF: 9.466; 2013 IF: 8.535
  Call Number UA @ lucian @ c:irua:112248 Serial 3434
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Author Pietra, F.; van Dijk-Moes, R.J.A.; Ke, X.; Bals, S.; Van Tendeloo, G.; de Mello Donega, C.; Vanmaekelbergh, D.
  Title Synthesis of highly luminescent silica-coated CdSe/CdS nanorods Type A1 Journal article
  Year (down) 2013 Publication Chemistry of materials Abbreviated Journal Chem Mater
  Volume 25 Issue 17 Pages 3427-3434
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract CdSe(core)/CdS(shell) nanorods (NRs) have been extensively investigated for their unique optical properties, such as high photoluminescence (PL) quantum efficiency (QE) and polarized light emission. The incorporation of these NRs in silica (SiO2) is of high interest, since this renders them processable in polar solvents while increasing their photochemical stability, which would be beneficial for their application in LEDs and as biolabels. We report the synthesis of highly luminescent silica-coated CdSe/CdS NRs, by using the reverse micelle method. The mechanism for the encapsulation of the NRs in silica is unravelled and shown to be strongly influenced by the NR shape and its asymmetry. This is attributed to both the different morphology and the different crystallographic nature of the facets terminating the opposite tips of the NRs. These results lead to the formation of a novel class of NR architectures, whose symmetry can be controlled by tuning the degree of coverage of the silica shell. Interestingly, the encapsulation of the NRs in silica leads to a remarkable increase in their photostability, while preserving their optical properties.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Washington, D.C. Editor
  Language Wos 000330097900004 Publication Date 2013-08-13
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0897-4756;1520-5002; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 9.466 Times cited 46 Open Access
  Notes 262348 ESMI; 246791 COUNTATOMS; Hercules Approved Most recent IF: 9.466; 2013 IF: 8.535
  Call Number UA @ lucian @ c:irua:110037 Serial 3456
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Author Singh, S.K.; Srinivasan, S.G.; Neek-Amal, M.; Costamagna, S.; van Duin, A.C.T.; Peeters, F.M.
  Title Thermal properties of fluorinated graphene Type A1 Journal article
  Year (down) 2013 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 87 Issue 10 Pages 104114-104116
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract Large-scale atomistic simulations using the reactive force field approach are implemented to investigate the thermomechanical properties of fluorinated graphene (FG). A set of parameters for the reactive force field potential optimized to reproduce key quantum mechanical properties of relevant carbon-fluorine cluster systems are presented. Molecular dynamics simulations are used to investigate the thermal rippling behavior of FG and its mechanical properties and compare them with graphene, graphane and a sheet of boron nitride. The mean square value of the height fluctuations < h(2)> and the height-height correlation function H(q) for different system sizes and temperatures show that FG is an unrippled system in contrast to the thermal rippling behavior of graphene. The effective Young's modulus of a flake of fluorinated graphene is obtained to be 273 N/m and 250 N/m for a flake of FG under uniaxial strain along armchair and zigzag directions, respectively. DOI: 10.1103/PhysRevB.87.104114
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000316933500002 Publication Date 2013-03-29
  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 80 Open Access
  Notes ; M.N.-A. is supported by the EU-Marie Curie IIF postdoc Fellowship/299855. This work is supported by the ESF-Eurographene project CONGRAN, the Flemish Science Foundation (FWO-Vl), and the Methusalem Foundation of the Flemish Government. S. G. S. and A.C.T.vD. acknowledge support by the Air Force Office of Scientific Research (AFOSR) under Grant No. FA9550-10-1-0563. ; Approved Most recent IF: 3.836; 2013 IF: 3.664
  Call Number UA @ lucian @ c:irua:108495 Serial 3629
Permanent link to this record
 

 
Author Van Duppen, B.; Peeters, F.M.
  Title Thermodynamic properties of the electron gas in multilayer graphene in the presence of a perpendicular magnetic field Type A1 Journal article
  Year (down) 2013 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 88 Issue 24 Pages 245429-7
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract The thermodynamic properties of the electron gas in multilayer graphene depend strongly on the number of layers and the type of stacking. Here we analyze how those properties change when we vary the number of layers for rhombohedral stacked multilayer graphene and compare our results with those from a conventional two-dimensional electron gas. We show that the highly degenerate zero-energy Landau level which is partly filled with electrons and partly with holes has a strong influence on the values of the different thermodynamic quantities.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000328686900006 Publication Date 2014-01-09
  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 2 Open Access
  Notes ; The authors would like to thank C. De Beule for enlightening discussions. This work was supported by the European Science Foundation (ESF) under the EUROCORES Program Euro-GRAPHENE within the project CONGRAN, the Flemish Science Foundation (FWO-Vl) by an aspirant research grant to B.V.D., and the Methusalem Program of the Flemish Government. ; Approved Most recent IF: 3.836; 2013 IF: 3.664
  Call Number UA @ lucian @ c:irua:113700 Serial 3635
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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 (down) 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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