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Author Roditchev, D.; Brun, C.; Serrier-Garcia, L.; Cuevas, J.C.; Bessa, V.H.L.; Milošević, M.V.; Debontridder, F.; Stolyarov, V.; Cren, T.
  Title Direct observation of Josephson vortex cores Type A1 Journal article
  Year 2015 Publication Nature physics Abbreviated Journal Nat Phys
  Volume 11 Issue 11 Pages 332-337
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract Superconducting correlations may propagate between two superconductors separated by a tiny insulating or metallic barrier, allowing a dissipationless electric current to flow(1,2). In the presence of a magnetic field, the maximum supercurrent oscillates(3) and each oscillation corresponding to the entry of one Josephson vortex into the barrier(4). Josephson vortices are conceptual blocks of advanced quantum devices such as coherent terahertz generators(5) or qubits for quantum computing(6), in which on-demand generation and control is crucial. Here, we map superconducting correlations inside proximity Josephson junctions(7) using scanning tunnelling microscopy. Unexpectedly, we find that such Josephson vortices have real cores, in which the proximity gap is locally suppressed and the normal state recovered. By following the Josephson vortex formation and evolution we demonstrate that they originate from quantum interference of Andreev quasiparticles(8), and that the phase portraits of the two superconducting quantum condensates at edges of the junction decide their generation, shape, spatial extent and arrangement. Our observation opens a pathway towards the generation and control of Josephson vortices by applying supercurrents through the superconducting leads of the junctions, that is, by purely electrical means without any need for a magnetic field, which is a crucial step towards high-density on-chip integration of superconducting quantum devices.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000352163100016 Publication Date 2015-02-23
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1745-2473;1745-2481; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 22.806 Times cited 102 Open Access (up)
  Notes T.C., C.B., F.D., V.S. and D.R. acknowledge financial support from the French ANR project and the French-Russian program PICS-CNRS/RAS. The authors also thank V. Cherkez for assistance during experiments and V. Vinokur (Argonne National Laboratory, Illinois USA) and A. Buzdin (University of Bordeaux 1, France) for stimulating discussions. J.C.C. acknowledges financial support from the Spanish MICINN (Contract No. FIS2011-28851-C1). V.H.L.B. acknowledges support from CNPq Brazil and productive discussions with Prof. A. Chaves (UFC, Brazil). M.V.M. acknowledges support from Research Foundation Flanders (FWO-Vlaanderen) and CAPES Brazil (PVE project BEX1392/11-5). Approved Most recent IF: 22.806; 2015 IF: 20.147
  Call Number c:irua:132524 c:irua:132524 Serial 3943
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Author Zalfani, M.; van der Schueren, B.; Hu, Z.-Y.; Rooke, J.C.; Bourguiga, R.; Wu, M.; Li, Y.; Van Tendeloo, G.; Su, B.-L.
  Title Novel 3DOM BiVO4/TiO2nanocomposites for highly enhanced photocatalytic activity Type A1 Journal article
  Year 2015 Publication Journal of materials chemistry A : materials for energy and sustainability Abbreviated Journal J Mater Chem A
  Volume 3 Issue 3 Pages 21244-21256
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
  Abstract Novel 3DOM BiVO4/TiO2 nanocomposites with intimate contact were for the first time synthesized by a hydrothermal method in order to elucidate their visible-light-driven photocatalytic performances. BiVO4 nanoparticles and 3DOM TiO2 inverse opal were fabricated respectively. These materials were characterized by XRD, XPS, SEM, TEM, N2 adsorption–desorption and UV-vis diffuse (UV-vis) and photoluminescence spectroscopies. As references for comparison, a physical mixture of BiVO4 nanoparticles and 3DOM TiO2 inverse opal powder (0.08 : 1), and a BiVO4/P25 TiO2 (0.08 : 1) nanocomposite made also by the hydrothermal method were prepared. The photocatalytic performance of all the prepared materials was evaluated by the degradation of rhodamine B (RhB) as a model pollutant molecule under visible light irradiation. The highly ordered 3D macroporous inverse opal structure can provide more active surface areas and increased mass transfer because of its highly accessible 3D porosity. The results show that 3DOM BiVO4/TiO2 nanocomposites possess a highly prolonged lifetime and increased separation of visible light generated charges and extraordinarily high photocatalytic activity. Owing to the intimate contact between BiVO4 and large surface area 3DOM TiO2, the photogenerated high energy charges can be easily transferred from BiVO4 to the 3DOM TiO2 support. BiVO4 nanoparticles in the 3DOM TiO2 inverse opal structure act thus as a sensitizer to absorb visible light and to transfer efficiently high energy electrons to TiO2 to ensure long lifetime of the photogenerated charges and keep them well separated, owing to the direct band gap of BiVO4 of 2.4 eV, favourably positioned band edges, very low recombination rate of electron–hole pairs and stability when coupled with photocatalysts, explaining the extraordinarily high photocatalytic performance of 3DOM BiVO4/TiO2 nanocomposites. It is found that larger the amount of BiVO4 in the nanocomposite, longer the duration of photogenerated charge separation and higher the photocatalytic activity. This work can shed light on the development of novel visible light responsive nanomaterials for efficient solar energy utilisation by the intimate combination of an inorganic light sensitizing nanoparticle with an inverse opal structure with high diffusion efficiency and high accessible surface area.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000363163200049 Publication Date 2015-09-08
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 2050-7488;2050-7496; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 8.867 Times cited 88 Open Access (up)
  Notes This work was realized with the financial support of the Belgian FNRS (Fonds National de la Recherche Scientifique). This research used resources of the Electron Microscopy Service located at the University of Namur. This Service is a member of the “Plateforme Technologique Morphologie – Imagerie”. The XPS analyses were made in the LISE, Department of Physics of the University of Namur thanks to Dr P. Louette. This work was also supported by Changjiang Scholars and the Innovative Research Team (IRT1169) of the Ministry of Education of the People's Republic of China. B. L. Su acknowledges the Chinese Central Government for an “Expert of the State” position in the Program of the “Thousand Talents” and a Clare Hall Life Membership at the Clare Hall and the financial support of the Department of Chemistry, University of Cambridge. G. Van Tendeloo and Z. Y. Hu acknowledge support from the EC Framework 7 program ESTEEM2 (Reference 312483).; esteem2_jra4 Approved Most recent IF: 8.867; 2015 IF: 7.443
  Call Number c:irua:129476 c:irua:129476 Serial 3951
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Author Dong, H.M.; Qin, H.; Zhang, J.; Peeters, F.M.; Xu, W.
  Title Terahertz absorption window in bilayer graphene Type H1 Book chapter
  Year 2009 Publication Abbreviated Journal
  Volume Issue Pages 247-248
  Keywords H1 Book chapter; Condensed Matter Theory (CMT)
  Abstract We present a detailed theoretical study of terahertz (THz) optical absorption in bilayer graphene. Considering an air/graphene/dielectric-wafer system, we find that there is an absorption window in the range 3 similar to 30 THz. Such an absorption window is induced by different transition energies required for inter- and intra-band optical absorption in the presence of the Pauli blockade effect. As a result, the position and width of this THz absorption window depend sensitively on temperature and carrier density of the system. These results are pertinent to the applications of recently developed graphene systems as novel optoelectronic devices such as THz photo-detectors.
  Address
  Corporate Author Thesis
  Publisher Ieee Place of Publication New York, N.Y. Editor
  Language Wos Publication Date 0000-00-00
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN ISBN 978-1-4244-5416-7 Additional Links UA library record; WoS full record;
  Impact Factor Times cited Open Access (up)
  Notes Approved Most recent IF: NA
  Call Number UA @ lucian @ c:irua:99225 Serial 3506
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Author Zeng, Y.-J.; Gauquelin, N.; Li, D.-Y.; Ruan, S.-C.; He, H.-P.; Egoavil, R.; Ye, Z.-Z.; Verbeeck, J.; Hadermann, J.; Van Bael, M.J.; Van Haesendonck, C.
  Title Co-Rich ZnCoO Nanoparticles Embedded in Wurtzite Zn1-xCoxO Thin Films: Possible Origin of Superconductivity Type A1 Journal article
  Year 2015 Publication ACS applied materials and interfaces Abbreviated Journal Acs Appl Mater Inter
  Volume 7 Issue 7 Pages 22166-22171
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
  Abstract Co-rich ZnCoO nanoparticles embedded in wurtzite Zn0.7Co0.3O thin films are grown by pulsed laser deposition on a Si substrate. Local superconductivity with an onset Tc at 5.9 K is demonstrated in the hybrid system. The unexpected superconductivity probably results from Co(3+) in the Co-rich ZnCoO nanoparticles or from the interface between the Co-rich nanoparticles and the Zn0.7Co0.3O matrix.
  Address Solid State Physics and Magnetism Section, KU Leuven , Celestijnenlaan 200 D, BE-3001 Leuven, Belgium
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language English Wos 000363001500007 Publication Date 2015-09-21
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1944-8244;1944-8252; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 7.504 Times cited 13 Open Access (up)
  Notes This work has been supported by the Research Foundation − Flanders (FWO, Belgium) as well as by the Flemish Concerted Research Action program (BOF KU Leuven, GOA/14/007). N. G. and J. V. acknowledge funding from the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant 278510 VORTEX. The Qu-Ant-EM microscope was partly funded by the Flemish Hercules Foundation. The work at Shenzhen University was supported by National Natural Science Foundation of China under Grant No. 61275144 and Natural Science Foundation of SZU. Y.-J. Z. acknowledges funding under grant No. SKL2015-12 from the State Key Laboratory of Silicon Materials; ECASJO_; Approved Most recent IF: 7.504; 2015 IF: 6.723
  Call Number c:irua:129195 c:irua:129195UA @ admin @ c:irua:129195 Serial 3949
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Author Lao, M.; Eisterer, M.; Stadel, O.; Meledin, A.; Van Tendeloo, G.
  Title The effect of Y2O3 and YFeO3 additions on the critical current density of YBCO coated conductors Type P1 Proceeding
  Year 2014 Publication 1-4 Abbreviated Journal
  Volume Issue Pages
  Keywords P1 Proceeding; Electron microscopy for materials research (EMAT)
  Abstract The pinning mechanism of MOCVD-grown YBCO coated conductors with Y2O3 precipitates was investigated by angle-resolved transport measurement of Je in a wide range of temperature and magnetic fields. Aside from the Y2O3 nanoprecipitates, a-axis grains and threading dislocation along the c-axis were found in the YBCO layer. The Y2O3 precipitates are less effective pinning centers at lower temperature. The tapes with precipitates show a higher anisotropy with larger J(c) at H parallel to ab than H parallel to c. This behavior was attributed to the preferred alignment of the nanoprecipitates along the ab-plane.
  Address
  Corporate Author Thesis
  Publisher Iop publishing ltd Place of Publication Bristol Editor
  Language Wos 000350818300068 Publication Date 2014-05-12
  Series Editor Series Title Abbreviated Series Title
  Series Volume 507 Series Issue Edition
  ISSN 1742-6596; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor Times cited 1 Open Access (up)
  Notes eurotapes Approved Most recent IF: NA
  Call Number UA @ lucian @ c:irua:125444 Serial 3577
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Author Leusink, D.P.; Coneri, F.; Hoek, M.; Turner, S.; Idrissi, H.; Van Tendeloo, G.; Hilgenkamp, H.
  Title Thin films of the spin ice compound Ho2Ti2O7 Type A1 Journal article
  Year 2014 Publication APL materials Abbreviated Journal Apl Mater
  Volume 2 Issue 3 Pages 032101-32107
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
  Abstract The pyrochlore compounds Ho2Ti2O7 and Dy2Ti2O7 show an exotic form of magnetism called the spin ice state, resulting from the interplay between geometrical frustration and ferromagnetic coupling. A fascinating feature of this state is the appearance of magnetic monopoles as emergent excitations above the degenerate ground state. Over the past years, strong effort has been devoted to the investigation of these monopoles and other properties of the spin ice state in bulk crystals. Here, we report the fabrication of Ho2Ti2O7 thin films using pulsed laser deposition on yttria-stabilized ZrO2 substrates. We investigated the structural properties of these films by X-ray diffraction, scanning transmission electron microscopy, and atomic force microscopy, and the magnetic properties by vibrating sample magnetometry at 2 K. The films not only show a high crystalline quality, but also exhibit the hallmarks of a spin ice: a pronounced magnetic anisotropy and an intermediate plateau in the magnetization along the [111] crystal direction.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000334220300002 Publication Date 2014-03-04
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 2166-532X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 4.335 Times cited 18 Open Access (up)
  Notes The authors acknowledge support from the Dutch FOM and NWO foundations and from the European Union under the Framework 7 program under a contract from an Integrated Infrastructure Initiative (Reference 312483 ESTEEM2). G.V.T. acknowledges the ERC Grant N246791- COUNTATOMS. S.T. gratefully acknowledges financial support from the Fund for Scientific Research Flanders (FWO). H.I. acknowledges the IAP program of the Belgian State Federal Office for Scientific, Technical and Cultural Affairs under Contract No. P7/21. The microscope used in this study was partially financed by the Hercules Foundation of the Flemish Government. The authors acknowledge fruitful interactions with A. Brinkman, M. G. Blamire, M. Egilmez, F. J. G. Roesthuis, J. N. Beukers, C. G. Molenaar, M. Veldhorst, and X. Renshaw Wang; esteem2_ta Approved Most recent IF: 4.335; 2014 IF: NA
  Call Number UA @ lucian @ c:irua:115555 Serial 3641
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Author Goris, B.; de Backer, A.; Van Aert, S.; Gómez-Graña, S.; Liz-Marzán, L.M.; Van Tendeloo, G.; Bals, S.
  Title Three-dimensional elemental mapping at the atomic scale in bimetallic nanocrystals Type A1 Journal article
  Year 2013 Publication Nano letters Abbreviated Journal Nano Lett
  Volume 13 Issue 9 Pages 4236-4241
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
  Abstract A thorough understanding of the three-dimensional (3D) atomic structure and composition of coreshell nanostructures is indispensable to obtain a deeper insight on their physical behavior. Such 3D information can be reconstructed from two-dimensional (2D) projection images using electron tomography. Recently, different electron tomography techniques have enabled the 3D characterization of a variety of nanostructures down to the atomic level. However, these methods have all focused on the investigation of nanomaterials containing only one type of chemical element. Here, we combine statistical parameter estimation theory with compressive sensing based tomography to determine the positions and atom type of each atom in heteronanostructures. The approach is applied here to investigate the interface in coreshell Au@Ag nanorods but it is of great interest in the investigation of a broad range of nanostructures.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Washington Editor
  Language Wos 000330158900043 Publication Date 2013-08-16
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1530-6984;1530-6992; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 12.712 Times cited 90 Open Access (up)
  Notes FWO; 246791 COUNTATOMS; 267867 PLASMAQUO; 262348 ESMI; 312483 ESTEEM2; Hercules 3; esteem2_jra4 Approved Most recent IF: 12.712; 2013 IF: 12.940
  Call Number UA @ lucian @ c:irua:110036 Serial 3650
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Author Gong, X.; Marmy, P.; Volodin, A.; Amin-Ahmadi, B.; Qin, L.; Schryvers, D.; Gavrilov, S.; Stergar, E.; Verlinden, B.; Wevers, M.; Seefeldt, M.
  Title Multiscale investigation of quasi-brittle fracture characteristics in a 9Cr–1Mo ferritic–martensitic steel embrittled by liquid lead–bismuth under low cycle fatigue Type A1 Journal article
  Year 2016 Publication Corrosion science Abbreviated Journal
  Volume 102 Issue 102 Pages 137-152
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
  Abstract Liquid metal embrittlement (LME) induced quasi-brittle fracture characteristics of a 9Cr–1Mo ferritic–martensitic steel (T91) after fatigue cracking in lead–bismuth eutectic (LBE) have been investigated at various length scales. The results show that the LME fracture morphology is primarily characterized by quasi-brittle translath flat regions partially covered by nanodimples, shallow secondary cracks propagating along the martensitic lath boundaries as well as tear ridges covered by micro dimples. These diverse LME fracture features likely indicate a LME mechanism involving multiple physical processes, such as weakening induced interatomic decohesion at the crack tip and plastic shearing induced nano/micro voiding in the plastic zone.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000367275700014 Publication Date 2015-10-22
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0010938X ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor Times cited 16 Open Access (up)
  Notes The work is financially supported by the MYRRHA project,SCK•CEN, Belgium and partly funded by the European AtomicEnergy Community’s (Euratom) Seventh Framework ProgrammeFP7/2007-2013 under grant agreement No. 604862 (MatISSEproject) and in the framework of the EERA (European EnergyResearch Alliance) Joint Programme on Nuclear Materials. Dr. TomVan der Donck (KU Leuven) is acknowledged for the EBSD mea-surements. The authors are grateful to Dr. Van Renterghem Wouter(SCK•CEN) for fruitful discussion of the TEM results. Xing Gongsincerely acknowledges valuable suggestions from Dr. S.P. Lynch(Defence Science and Technology Organisation and Monash Uni-versity, Melbourne, Australia). Approved Most recent IF: NA
  Call Number c:irua:129997 Serial 4013
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Author Zhang, L.-F.; Covaci, L.; Peeters, F.M.
  Title Tomasch effect in nanoscale superconductors Type A1 Journal article
  Year 2015 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 91 Issue 91 Pages 024508
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract The Tomasch effect (TE) is due to quasiparticle interference (QPI) as induced by a nonuniform superconducting order parameter, which results in oscillations in the density of states (DOS) at energies above the superconducting gap. Quantum confinement in nanoscale superconductors leads to an inhomogenerous distribution of the Cooperpair condensate, which, as we found, triggers the manifestation of a new TE. We investigate the electronic structure of nanoscale superconductors by solving the Bogoliubov-de Gennes (BdG) equations self-consistently and describe the TE determined by two types of processes, involving two-or three-subband QPIs. Both types of QPIs result in additional BCS-like Bogoliubov-quasiparticles and BCS-like energy gaps leading to oscillations in the DOS and modulated wave patterns in the local density of states. These effects are strongly related to the symmetries of the system. A reduced 4 x 4 inter-subband BdG Hamiltonian is established in order to describe analytically the TE of two-subband QPIs. Our study is relevant to nanoscale superconductors, either nanowires or thin films, Bose-Einsten condensates, and confined systems such as two-dimensional electron gas interface superconductivity.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Lancaster, Pa Editor
  Language Wos 000348473700003 Publication Date 2015-01-16
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 3.836 Times cited 6 Open Access (up)
  Notes ; This work was supported by the Flemish Science Foundation (FWO-Vlaanderen) and the Methusalem funding of the Flemish Government. ; Approved Most recent IF: 3.836; 2015 IF: 3.736
  Call Number c:irua:123864 Serial 3670
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Author Croitoru, M.D.; Shanenko, A.A.; Peeters, F.M.
  Title Tuning the superconducting properties of nanomaterials Type H1 Book chapter
  Year 2009 Publication Abbreviated Journal
  Volume Issue Pages 1-14
  Keywords H1 Book chapter; Condensed Matter Theory (CMT); Electron microscopy for materials research (EMAT)
  Abstract Electron continement and its effect on the superconducting-to-normal phase transition driven by a magentic field and/or a current is studied in nanowires. Our investigation is based on a self-consistent numerical solution of the Bogoliubov-de Gennes equations. We find that in a parallel magneitc field and/or in the presence of a supercurrent the transition from the superconducting to the normal phase occurs as a cascade of discontinuous jumps in the superconducting order parameter for diameters D < 10 divided by 15 nm at T = 0. The critical magentic field exhibits quantum-size oscillations with pronounced resonant enhancements as a function of the wire radius.
  Address
  Corporate Author Thesis
  Publisher Springer Place of Publication Dordrecht Editor
  Language Wos 000274282900001 Publication Date 2009-07-29
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1874-6500; ISBN 978-90-481-3118-1 Additional Links UA library record; WoS full record
  Impact Factor Times cited Open Access (up)
  Notes Approved Most recent IF: NA
  Call Number UA @ lucian @ c:irua:99226 Serial 3761
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Author Deo, P.S.; Schweigert, V.A.; Peeters, F.M.; Geim, A.K.
  Title Type of phase transitions in a mesoscopic superconducting disc Type A1 Journal article
  Year 1997 Publication Physica: E Abbreviated Journal Physica E
  Volume 1 Issue Pages 297-300
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000074364500064 Publication Date 2002-07-25
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1386-9477; ISBN Additional Links UA library record; WoS full record;
  Impact Factor 2.221 Times cited Open Access (up)
  Notes Approved Most recent IF: 2.221; 1997 IF: NA
  Call Number UA @ lucian @ c:irua:19299 Serial 3791
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Author Milošević, M.V.; Perali, A.
  Title Emergent phenomena in multicomponent superconductivity: an introduction to the focus issue Type A1 Journal article
  Year 2015 Publication Superconductor Science & Technology Abbreviated Journal Supercond Sci Tech
  Volume 28 Issue 28 Pages 060201
  Keywords A1 Journal article; CMT
  Abstract
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000354110200001 Publication Date 2015-04-24
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0953-2048;1361-6668; ISBN Additional Links
  Impact Factor 2.878 Times cited 41 Open Access (up)
  Notes ; ; Approved Most recent IF: 2.878; 2015 IF: 2.325
  Call Number UA @ lucian @ Serial 3945
Permanent link to this record
 

 
Author Juchtmans, R.; Béché, A.; Abakumov, A.; Batuk, M.; Verbeeck, J.
  Title Using electron vortex beams to determine chirality of crystals in transmission electron microscopy Type A1 Journal article
  Year 2015 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 91 Issue 91 Pages 094112
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract We investigate electron vortex beams elastically scattered on chiral crystals. After deriving a general expression for the scattering amplitude of a vortex electron, we study its diffraction on point scatterers arranged on a helix. We derive a relation between the handedness of the helix and the topological charge of the electron vortex on one hand and the symmetry of the higher-order Laue zones in the diffraction pattern on the other for kinematically and dynamically scattered electrons. We then extend this to atoms arranged on a helix as found in crystals which belong to chiral space groups and propose a method to determine the handedness of such crystals by looking at the symmetry of the diffraction pattern. In contrast to alternative methods, our technique does not require multiple scattering, which makes it possible to also investigate extremely thin samples in which multiple scattering is suppressed. In order to verify the model, elastic scattering simulations are performed, and an experimental demonstration on Mn2Sb2O7 is given in which we find the sample to belong to the right-handed variant of its enantiomorphic pair. This demonstrates the usefulness of electron vortex beams to reveal the chirality of crystals in a transmission electron microscope and provides the required theoretical basis for further developments in this field.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000352017000002 Publication Date 2015-03-27
  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 54 Open Access (up)
  Notes Fwo; 312483 Esteem2; 278510 Vortex; esteem2jra1; esteem2jra2 ECASJO_; Approved Most recent IF: 3.836; 2015 IF: 3.736
  Call Number c:irua:125512 c:irua:125512 Serial 3825
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Author Shanenko, A.A.; Aguiar, J.A.; Vagov, A.; Croitoru, M.D.; Milošević, M.V.
  Title Atomically flat superconducting nanofilms: multiband properties and mean-field theory Type A1 Journal article
  Year 2015 Publication Superconductor science and technology Abbreviated Journal Supercond Sci Tech
  Volume 28 Issue 28 Pages 054001
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract Recent progress in materials synthesis enabled fabrication of superconducting atomically flat single-crystalline metallic nanofilms with thicknesses down to a few monolayers. Interest in such nano-thin systems is attracted by the dimensional 3D-2D crossover in their coherent properties which occurs with decreasing the film thickness. The first fundamental aspect of this crossover is dictated by the Mermin-Wagner-Hohenberg theorem and concerns frustration of the long-range order due to superconductive fluctuations and the possibility to track its impact with an unprecedented level of control. The second important aspect is related to the Fabri-Perot modes of the electronic motion strongly bound in the direction perpendicular to the nanofilm. The formation of such modes results in a pronounced multiband structure that changes with the nanofilm thickness and affects both the mean-field behavior and superconductive fluctuations. Though the subject is very rich in physics, it is scarcely investigated to date. The main obstacle is that there are no manageable models to study a complex magnetic response in this case. Full microscopic consideration is rather time consuming, if practicable at all, while the standard Ginzburg-Landau theory is not applicable. In the present work we review the main achievements in the subject to date, and construct and justify an efficient multiband mean-field formalism which allows for numerical and even analytical treatment of nano-thin superconductors in applied magnetic fields.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000353015700005 Publication Date 2015-03-19
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0953-2048;1361-6668; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 2.878 Times cited 23 Open Access (up)
  Notes This work was supported by the Brazilian agencies CNPq (grants 307552/2012-8 and 141911/2012-3) and FACEPE (APQ-0589-1.05/08). AAS acknowledges fruitful discussions with A Perali and D Neilson during his stay in the University of Camerino and is thankful for partial support of his visit by the University of Camerino under the project FAR 'Control and enhancement of superconductivity by engineering materials at the nanoscale'. MDC acknowledges the support from the Back to Belgium Grant of the federal Science Policy (BELSPO). Approved Most recent IF: 2.878; 2015 IF: 2.325
  Call Number c:irua:132501 Serial 3944
Permanent link to this record
 

 
Author Ludu, A.; Milošević, M.V.; Peeters, F.M.
  Title Vortex states in axially symmetric superconductors in applied magnetic field Type A1 Journal article
  Year 2012 Publication Sn – 0378-4754 Abbreviated Journal Math Comput Simulat
  Volume 82 Issue 7 Pages 1258-1270
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract We solve analytically the linearized Ginzburg-Landau (GL) equation in the presence of an uniform magnetic field with cylindrical boundary conditions. The solution of the non-linear GL equation is provided as an expansion in the basis of linearized solutions. We present examples of the resulting vortex structure for a solid and perforated superconducting cylinder. (C) 2012 IMACS. Published by Elsevier B.V. All rights reserved.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Amsterdam Editor
  Language Wos 000303097000009 Publication Date 2012-02-11
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0378-4754; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 1.218 Times cited 1 Open Access (up)
  Notes ; ; Approved Most recent IF: 1.218; 2012 IF: 0.836
  Call Number UA @ lucian @ c:irua:98300 Serial 3887
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Author Zhang, L.-F.; Covaci, L.; Milošević, M.V.; Berdiyorov, G.R.; Peeters, F.M.
  Title Vortex states in nanoscale superconducting squares : the influence of quantum confinement Type A1 Journal article
  Year 2013 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 88 Issue 14 Pages 144501
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract Bogoliubov-de Gennes theory is used to investigate the effect of the size of a superconducting square on the vortex states in the quantum confinement regime. When the superconducting coherence length is comparable to the Fermi wavelength, the shape resonances of the superconducting order parameter have strong influence on the vortex configuration. Several unconventional vortex states, including asymmetric ones, giant-multivortex combinations, and states comprising giant antivortices, were found as ground states and their stability was found to be very sensitive on the value of k(F)xi(0), the size of the sample W, and the magnetic flux Phi. By increasing the temperature and/or enlarging the size of the sample, quantum confinement is suppressed and the conventional mesoscopic vortex states as predicted by the Ginzburg-Laudau (GL) theory are recovered. However, contrary to the GL results we found that the states containing symmetry-induced vortex-antivortex pairs are stable over the whole temperature range. It turns out that the inhomogeneous order parameter induced by quantum confinement favors vortex-antivortex molecules, as well as giant vortices with a rich structure in the vortex core-unattainable in the GL domain.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000325498300004 Publication Date 2013-10-09
  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 19 Open Access (up)
  Notes ; This work was supported by the Flemish Science Foundation (FWO-Vlaanderen) and Methusalem Funding of the Flemish government. ; Approved Most recent IF: 3.836; 2013 IF: 3.664
  Call Number UA @ lucian @ c:irua:111145 Serial 3891
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Author Molina-Luna, L.; Duerrschnabel, M.; Turner, S.; Erbe, M.; Martinez, G.T.; Van Aert, S.; Holzapfel, B.; Van Tendeloo, G.
  Title Atomic and electronic structures of BaHfO3-doped TFA-MOD-derived YBa2Cu3O7−δthin films Type A1 Journal article
  Year 2015 Publication Superconductor science and technology Abbreviated Journal Supercond Sci Tech
  Volume 28 Issue 28 Pages 115009
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract Tailoring the properties of oxide-based nanocomposites is of great importance for a wide range of materials relevant for energy technology. YBa2Cu3O7−δ (YBCO) superconducting thin films containing nanosized BaHfO3 (BHO) particles yield a significant improvement of the magnetic flux pinning properties and a reduced anisotropy of the critical current density. These films were prepared by chemical solution deposition (CSD) on (100) SrTiO3 (STO) substrates yielding critical current densities up to 3.6 MA cm−2 at 77 K and self-field. Transport in-field J c measurements demonstrated a high pinning force maximum of around 6 GN/m3 for a sample annealed at T = 760 °C that has a doping of 12 mol% of BHO. This sample was investigated by scanning transmission electron microscopy (STEM) in combination with electron energy-loss spectroscopy (EELS) yielding strain and spectral maps. Spherical BHO nanoparticles of 15 nm in size were found in the matrix, whereas the particles at the interface were flat. A 2 nm diffusion layer containing Ti was found at the YBCO (BHO)/STO interface. Local lattice deformation mapping at the atomic scale revealed crystal defects induced by the presence of both sorts of BHO nanoparticles, which can act as pinning centers for magnetic flux lines. Two types of local lattice defects were identified and imaged: (i) misfit edge dislocations and (ii) Ba-Cu-Cu-Ba stacking faults (Y-248 intergrowths). The local electronic structure and charge transfer were probed by high energy resolution monochromated electron energy-loss spectroscopy. This technique made it possible to distinguish superconducting from non-superconducting areas in nanocomposite samples with atomic resolution in real space, allowing the identification of local pinning sites on the order of the coherence length of YBCO (~1.5 nm) and the determination of 0.25 nm dislocation cores.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000366193000018 Publication Date 2015-09-25
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0953-2048;1361-6668; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 2.878 Times cited 4 Open Access (up)
  Notes The authors thank financial support from the European Union under the Framework 6 program as a contract for an Integrated Infrastructure Initiative (References No. 026019 ESTEEM) and by the EUFP6 Research Project “NanoEngineered Superconductors for Power Applications” NESPA no. MRTN-CT-2006-035619. This work was supported by funding from the European Research Council under the Seventh Framework Programme (FP7). L.M.L, S.T. and G.V.T acknowledge ERC grant N°246791 – COUNTATOMS and funding under a contract for an Integrated Infrastructure Initiative, Reference No. 312483- ESTEEM2, as well as the EC project EUROTAPES. G.T.M. and S.V.A acknowledge financial support from the Fund for Scientific Research-Flanders (Reference G.0064.10N and G.0393.11N). M.D. acknowledges financial support from the LOEWE research cluster RESPONSE (Hessen, Germany). M.E. has received funding from the European Union Seventh Framework Programme (FP7/2007–2013) under grant agreement n° NMP-LA-2012-280432.; esteem2jra2; esteem2jra3 Approved Most recent IF: 2.878; 2015 IF: 2.325
  Call Number c:irua:129199 c:irua:129199 Serial 3942
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Author Erbe, M.; Hänisch, J.; Hühne, R.; Freudenberg, T.; Kirchner, A.; Molina-Luna, L.; Damm, C.; Van Tendeloo, G.; Kaskel, S.; Schultz, L.; Holzapfel, B.
  Title BaHfO3artificial pinning centres in TFA-MOD-derived YBCO and GdBCO thin films Type A1 Journal article
  Year 2015 Publication Superconductor science and technology Abbreviated Journal Supercond Sci Tech
  Volume 28 Issue 28 Pages 114002
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract Chemical solution deposition (CSD) is a promising way to realize REBa2Cu3O7−x (REBCO;RE = rare earth (here Y, Gd))-coated conductors with high performance in applied magnetic fields. However, the preparation process contains numerous parameters which need to be tuned to achieve high-quality films. Therefore, we investigated the growth of REBCO thin films containing nanometre-scale BaHfO3 (BHO) particles as pinning centres for magnetic flux lines, with emphasis on the influence of crystallization temperature and substrate on the microstructure and superconductivity. Conductivity, microscopy and x-ray investigations show an enhanced performance of BHO nano-composites in comparison to pristine REBCO. Further, those measurements reveal the superiority of GdBCO to YBCO—e.g. by inductive critical current densities, Jc, at self-field and 77 K. YBCO is outperformed by more than 1 MA cm−2 with Jc values of up to 5.0 MA cm−2 for 265 nm thick layers of GdBCO(BHO) on lanthanum aluminate. Transport in-field Jc measurements demonstrate high pinning force maxima of around 4 GN m−3 for YBCO(BHO) and GdBCO(BHO). However, the irreversibility fields are appreciably higher for GdBCO. The critical temperature was not significantly reduced upon BHO addition to both YBCO and GdBCO, indicating a low tendency for Hf diffusion into the REBCO matrix. Angular-dependent Jc measurements show a reduction of the anisotropy in the same order of magnitude for both REBCO compounds. Theoretical models suggest that more than one sort of pinning centre is active in all CSD films.
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  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000366193000003 Publication Date 2015-09-25
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0953-2048;1361-6668; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 2.878 Times cited 36 Open Access (up)
  Notes Experimental work was mainly done at IFW Dresden. We thank Juliane Scheiter and Dr Jens Ingolf Mönch of IFW Dresden for technical assistance. The research leading to these results received funding from EUROTAPES, a collaborative project funded by the European Union Seventh Framework Programme (FP7/2007–2013) under grant agreement no. NMP-LA-2012-280 432. L Molina-Luna and G Van Tendeloo acknowledge funding from the European Research Council (ERC grant nr. 24 691-COUNTATOMS). Approved Most recent IF: 2.878; 2015 IF: 2.325
  Call Number c:irua:129200 Serial 3941
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Author Jelić, Ž.L.; Milošević, M.V.; Van de Vondel, J.; Silhanek, A.V.
  Title Stroboscopic phenomena in superconductors with dynamic pinning landscape Type A1 Journal article
  Year 2015 Publication Scientific reports Abbreviated Journal Sci Rep-Uk
  Volume 5 Issue 5 Pages 14604
  Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
  Abstract Introducing artificial pinning centers is a well established strategy to trap quantum vortices and increase the maximal magnetic field and applied electric current that a superconductor can sustain without dissipation. In case of spatially periodic pinning, a clear enhancement of the superconducting critical current arises when commensurability between the vortex configurations and the pinning landscape occurs. With recent achievements in (ultrafast) optics and nanoengineered plasmonics it has become possible to exploit the interaction of light with superconductivity, and create not only spatially periodic imprints on the superconducting condensate, but also temporally periodic ones. Here we show that in the latter case, temporal matching phenomena develop, caused by stroboscopic commensurability between the characteristic frequency of the vortex motion under applied current and the frequency of the dynamic pinning. The matching resonances persist in a broad parameter space, including magnetic field, driving current, or material purity, giving rise to unusual features such as externally variable resistance/impedance and Shapiro steps in current-voltage characteristics. All features are tunable by the frequency of the dynamic pinning landscape. These findings open further exploration avenues for using flashing, spatially engineered, and/or mobile excitations on superconductors, permitting us to achieve advanced functionalities.
  Address Departement de Physique, Universite de Liege, Allee du 6-Aout 17, B-4000 Liege, Belgium
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language English Wos 000362082500001 Publication Date 2015-10-01
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 2045-2322 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 4.259 Times cited 29 Open Access (up)
  Notes Acknowledgements: This work was supported by the Methusalem Funding of the Flemish Government, the Research Foundation-Flanders (FWO) and the COST Action MP1201. The work of Ž.L.J. and A.V.S. was partially supported by “Mandat d’Impulsion Scientifique” of the F.R.S.-FNRS. Approved Most recent IF: 4.259; 2015 IF: 5.578
  Call Number c:irua:129807 c:irua:129807 Serial 3980
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Author Adami, O.-A.; Jelić, Ž.L.; Xue, C.; Abdel-Hafiez, M.; Hackens, B.; Moshchalkov, V.V.; Milošević, M.V.; Van de Vondel, J.; Silhanek, A.V.
  Title Onset, evolution, and magnetic braking of vortex lattice instabilities in nanostructured superconducting films Type A1 Journal article
  Year 2015 Publication Physical review: B: condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 92 Issue 92 Pages 134506
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract In 1976, Larkin and Ovchinnikov [Zh. Eksp. Teor. Fiz. 68, 1915 (1975) [Sov. Phys.–JETP 41, 960 (1976)]] predicted that vortex matter in superconductors driven by an electrical current can undergo an abrupt dynamic transition from a flux-flow regime to a more dissipative state at sufficiently high vortex velocities. Typically, this transition manifests itself as a large voltage jump at a particular current density, so-called instability current density J∗, which is smaller than the depairing current. By tuning the effective pinning strength in Al films, using an artificial periodic pinning array of triangular holes, we show that a unique and well-defined instability current density exists if the pinning is strong, whereas a series of multiple voltage transitions appear in the relatively weaker pinning regime. This behavior is consistent with time-dependent Ginzburg-Landau simulations, where the multiple-step transition can be unambiguously attributed to the progressive development of vortex chains and subsequently phase-slip lines. In addition, we explore experimentally the magnetic braking effects, caused by a thick Cu layer deposited on top of the superconductor, on the instabilities and the vortex ratchet effect.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000362433200003 Publication Date 2015-10-08
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1098-0121 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 3.836 Times cited 21 Open Access (up)
  Notes ACKNOWLEDGMENTS: This work was partially supported by the Fonds de la Recherche Scientifique-FNRS, the Methusalem Funding of the Flemish Government, the Research Foundation-Flanders (FWO), and COST Action MP1201. The work of A.V.S. and Z.L.J. is partially supported by “Mandat d’Impulsion Scientifique” MIS F.4527.13 of the F.R.S.-FNRS. B.H. is an associate researcher of the Fonds de la Recherche Scientifique- FNRS. The authors thank J. Cuppens for the data analysis at the early stage of this work, R. Delamare for his valuable help during the fabrication of the samples, and G. Grimaldi for helpful discussions. Approved Most recent IF: 3.836; 2015 IF: 3.736
  Call Number c:irua:128747 Serial 3981
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Author Bogaerts, A.; Khosravian, N.; Van der Paal, J.; Verlackt, C.C.W.; Yusupov, M.; Kamaraj, B.; Neyts, E.C.
  Title Multi-level molecular modelling for plasma medicine Type A1 Journal article
  Year 2016 Publication Journal of physics: D: applied physics Abbreviated Journal J Phys D Appl Phys
  Volume 49 Issue 49 Pages 054002
  Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
  Abstract Modelling at the molecular or atomic scale can be very useful for obtaining a better insight in plasma medicine. This paper gives an overview of different atomic/molecular scale modelling approaches that can be used to study the direct interaction of plasma species with biomolecules or the consequences of these interactions for the biomolecules on a somewhat longer time-scale. These approaches include density functional theory (DFT), density functional based tight binding (DFTB), classical reactive and non-reactive molecular dynamics (MD) and united-atom or coarse-grained MD, as well as hybrid quantum mechanics/molecular mechanics (QM/MM) methods. Specific examples will be given for three important types of biomolecules, present in human cells, i.e. proteins, DNA and phospholipids found in the cell membrane. The results show that each of these modelling approaches has its specific strengths and limitations, and is particularly useful for certain applications. A multi-level approach is therefore most suitable for obtaining a global picture of the plasma–biomolecule interactions.
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  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000368944100003 Publication Date 2015-12-16
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0022-3727 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 2.588 Times cited 11 Open Access (up)
  Notes This work is financially supported by the Fund for Scientific Research Flanders (FWO) and the Francqui Foundation. The calculations were carried out in part using the Turing HPC infrastructure of the CalcUA core facility of the Universiteit Antwerpen, a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the Universiteit Antwerpen. Approved Most recent IF: 2.588
  Call Number c:irua:131571 Serial 3985
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Author Bal, K.M.; Neyts, E.C.
  Title Merging Metadynamics into Hyperdynamics: Accelerated Molecular Simulations Reaching Time Scales from Microseconds to Seconds Type A1 Journal article
  Year 2015 Publication Journal of chemical theory and computation Abbreviated Journal J Chem Theory Comput
  Volume 11 Issue 11 Pages 4545-4554
  Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
  Abstract The hyperdynamics method is a powerful tool to simulate slow processes at the atomic level. However, the construction of an optimal hyperdynamics potential is a task that is far from trivial. Here, we propose a generally applicable implementation of the hyperdynamics algorithm, borrowing two concepts from metadynamics. First, the use of a collective variable (CV) to represent the accelerated dynamics gives the method a very large flexibility and simplicity. Second, a metadynamics procedure can be used to construct a suitable history-dependent bias potential on-the-fly, effectively turning the algorithm into a self-learning accelerated molecular dynamics method. This collective variable-driven hyperdynamics (CVHD) method has a modular design: both the local system properties on which the bias is based, as well as the characteristics of the biasing method itself, can be chosen to match the needs of the considered system. As a result, system-specific details are abstracted from the biasing algorithm itself, making it extremely versatile and transparent. The method is tested on three model systems: diffusion on the Cu(001) surface and nickel-catalyzed methane decomposition, as examples of reactive processes with a bond-length-based CV, and the folding of a long polymer-like chain, using a set of dihedral angles as a CV. Boost factors up to 109, corresponding to a time scale of seconds, could be obtained while still accurately reproducing correct dynamics.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000362921700004 Publication Date 2015-09-02
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1549-9618 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 5.245 Times cited 41 Open Access (up)
  Notes K.M.B. is funded as Ph.D. fellow (aspirant) of the FWOFlanders (Fund for Scientific Research-Flanders), Grant No. 11 V8915N. The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), funded by the Hercules Foundation and the Flemish Government−Department EWI. Approved Most recent IF: 5.245; 2015 IF: 5.498
  Call Number c:irua:128183 Serial 3991
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Author Neyts, E.C.; Ostrikov, K.K.; Sunkara, M.K.; Bogaerts, A.
  Title Plasma Catalysis: Synergistic Effects at the Nanoscale Type A1 Journal article
  Year 2015 Publication Chemical reviews Abbreviated Journal Chem Rev
  Volume 115 Issue 115 Pages 13408-13446
  Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
  Abstract Thermal-catalytic gas processing is integral to many current industrial processes. Ever-increasing demands on conversion and energy efficiencies are a strong driving force for the development of alternative approaches. Similarly, synthesis of several functional materials (such as nanowires and nanotubes) demands special processing conditions. Plasma catalysis provides such an alternative, where the catalytic process is complemented by the use of plasmas that activate the source gas. This combination is often observed to result in a synergy between plasma and catalyst. This Review introduces the current state-of-the-art in plasma catalysis, including numerous examples where plasma catalysis has demonstrated its benefits or shows future potential, including CO2 conversion, hydrocarbon reforming, synthesis of nanomaterials, ammonia production, and abatement of toxic waste gases. The underlying mechanisms governing these applications, as resulting from the interaction between the plasma and the catalyst, render the process highly complex, and little is known about the factors leading to the often-observed synergy. This Review critically examines the catalytic mechanisms relevant to each specific application.
  Address Department of Chemistry, Research Group PLASMANT, Universiteit Antwerpen , Universiteitsplein 1, 2610 Wilrijk-Antwerp, Belgium
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language English Wos 000367563000006 Publication Date 2015-11-30
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0009-2665 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 47.928 Times cited 204 Open Access (up)
  Notes ECN and AB gratefully acknowledge financial support from the Fund of Scientific Research Flanders (FWO), Belgium, Grant Number G.0217.14N. KO acknowledges partial support by the Australian Research Council and CSIRO’s OCE Science Leaders Program. MKS acknowledges partial support from US National Science Foundation through grants DMS 1125909 and EPSCoR 1355448 and also PhD students Babajide Ajayi, Apolo Nambo and Maria Carreon for their help. Approved Most recent IF: 47.928; 2015 IF: 46.568
  Call Number c:irua:130001 Serial 3993
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Author Paria Sena, R.; Babaryk, A.A.; Khainakov, S.; Garcia-Granda, S.; Slobodyanik, N.S.; Van Tendeloo, G.; Abakumov, A.M.; Hadermann, J.
  Title A pseudo-tetragonal tungsten bronze superstructure: a combined solution of the crystal structure of K6.4(Nb,Ta)36.3O94 with advanced transmission electron microscopy and neutron diffraction Type A1 Journal article
  Year 2016 Publication Journal of the Chemical Society : Dalton transactions Abbreviated Journal Dalton T
  Volume 45 Issue 45 Pages 973-979
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract The crystal structure of the K6.4Nb28.2Ta8.1O94 pseudo-tetragonal tungsten bronze-type oxide was determined using a combination of X-ray powder diffraction, neutron diffraction and transmission electron microscopy techniques, including electron diffraction, high angle annular dark field scanning transmission electron microscopy (HAADF-STEM), annular bright field STEM (ABF-STEM) and energy-dispersive X-ray compositional mapping (STEM-EDX). The compound crystallizes in the space group Pbam with unit cell parameters a = 37.468(9) A, b = 12.493(3) A, c = 3.95333(15) A. The structure consists of corner sharing (Nb,Ta)O6 octahedra forming trigonal, tetragonal and pentagonal tunnels. All tetragonal tunnels are occupied by K(+) ions, while 1/3 of the pentagonal tunnels are preferentially occupied by Nb(5+)/Ta(5+) and 2/3 are occupied by K(+) in a regular pattern. A fractional substitution of K(+) in the pentagonal tunnels by Nb(5+)/Ta(5+) is suggested by the analysis of the HAADF-STEM images. In contrast to similar structures, such as K2Nb8O21, also parts of the trigonal tunnels are fractionally occupied by K(+) cations.
  Address Electron Microscopy for Materials Research (EMAT), University of Antwerp, Groenenborgerlaan 171, B-2020, Antwerp, Belgium. joke.hadermann@uantwerpen.be babaryk@univ.kiev.ua
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language English Wos 000367614700018 Publication Date 2015-11-23
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1477-9226 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 4.029 Times cited 6 Open Access (up)
  Notes We thank Dr E. Suard and Dr O. Fabello for assistance in collecting the neutron diffraction data. R.P.S. acknowledges funding from the European Research Council under the 7th Framework Program (FP7), ERC Grant No. 246791-COUNTATOMS. The titan microscope was partly funded by the Hercules fund from the Flemish Government. The authors acknowledge financial support from the European Union under the Seventh Framework Program under a contract for an Integrated Infrastructure Initiative. Reference No. 312483-ESTEEM2. AAB acknowledges the JSPDS ICDD Grant-in-Aid program (12-02).; esteem2jra1; esteem2jra2 Approved Most recent IF: 4.029
  Call Number c:irua:130408 c:irua:130408 Serial 3998
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Author Bertoni, G.; Fabbri, F.; Villani, M.; Lazzarini, L.; Turner, S.; Van Tendeloo, G.; Calestani, D.; Gradečak, S.; Zappettini, A.; Salviati, G.
  Title Nanoscale mapping of plasmon and exciton in ZnO tetrapods coupled with Au nanoparticles Type A1 Journal article
  Year 2016 Publication Scientific reports Abbreviated Journal Sci Rep-Uk
  Volume 6 Issue 6 Pages 19168
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
  Abstract Metallic nanoparticles can be used to enhance optical absorption or emission in semiconductors, thanks to a strong interaction of collective excitations of free charges (plasmons) with electromagnetic fields. Herein we present the direct imaging at the nanoscale of plasmon-exciton coupling in Au/ZnO nanostructures by combining scanning transmission electron energy loss and cathodoluminescence spectroscopy and mapping. The Au nanoparticles (~30 nm in diameter) are grown in-situ on ZnO nanotetrapods by means of a photochemical process without the need of binding agents or capping molecules. This results in clean interfaces, enabling to prove the occurrence of the plasmon-exciton coupling and the straightforward mapping of its spatial localization. Interestingly, the Au plasmon resonance is localized at the Au/vacuum interface, rather than presenting an isotropic distribution around the nanoparticle. On the contrary, a strong localization of the ZnO excitons, has been observed inside the Au nanoparticle, revealing the existence of the plasmon-exciton coupling, as also confirmed by numerical simulations.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000368111900001 Publication Date 2016-01-12
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 2045-2322 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 4.259 Times cited 15 Open Access (up)
  Notes The research leading to these results has received funding from the European Union FP7 Grant Agreement n. 265073 ITN-Nanowiring, and FP7 Grant Agreement n. 312483 ESTEEM2 for Integrated Infrastructure Initiative – I3. S.T. gratefully acknowledges the FWO Vlaanderen. G.V.T. acknowledges the European Research Council (ERC grant N°246791 – COUNTATOMS). The authors thank Alessandra Catellani and Arrigo Calzolari for helpful discussions.; Esteem2_jra3 Approved Most recent IF: 4.259
  Call Number c:irua:130406 c:irua:130406 Serial 3999
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Author Filez, M.; Redekop, E.A.; Galvita, V.V.; Poelman, H.; Meledina, M.; Turner, S.; Van Tendeloo, G.; Bell, A.T.; Marin, G.B.
  Title The role of hydrogen during Pt-Ga nanocatalyst formation Type A1 Journal article
  Year 2016 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys
  Volume 18 Issue 18 Pages 3234-3243
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract Hydrogen plays an essential role during the in situ assembly of tailored catalytic materials, and serves as key ingredient in multifarious chemical reactions promoted by these catalysts. Despite intensive debate for several decades, the existence and nature of hydrogen-involved mechanisms – such as hydrogen-spillover, surface migration – have not been unambiguously proven and elucidated up to date. Here, Pt-Ga alloy formation is used as a probe reaction to study the behavior and atomic transport of H and Ga, starting from Pt nanoparticles on hydrotalcite-derived Mg(Ga)(Al)Ox supports. In situ XANES spectroscopy, time-resolved TAP kinetic experiments, HAADF-STEM imaging and EDX mapping are combined to probe Pt, Ga and H in a series of H2 reduction experiments up to 650 degrees C. Mg(Ga)(Al)Ox by itself dissociates hydrogen, but these dissociated hydrogen species do not induce significant reduction of Ga3+ cations in the support. Only in the presence of Pt, partial reduction of Ga3+ into Gadelta+ is observed, suggesting that different reaction mechanisms dominate for Pt- and Mg(Ga)(Al)Ox-dissociated hydrogen species. This partial reduction of Ga3+ is made possible by Pt-dissociated H species which spillover onto non-reducible Mg(Al)Ox or partially reducible Mg(Ga)(Al)Ox and undergo long-range transport over the support surface. Moderately mobile Gadelta+Ox migrates towards Pt clusters, where Gadelta+ is only fully reduced to Ga0 on condition of immediate stabilization inside Pt-Ga alloyed nanoparticles.
  Address Laboratory for Chemical Technology (LCT), Ghent University, Technologiepark 914, B-9052 Ghent, Belgium. hilde.poelman@ugent.be
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language English Wos 000369506000106 Publication Date 2016-01-04
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1463-9076 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 4.123 Times cited 10 Open Access (up)
  Notes This work was supported by the Fund for Scientific Research Flanders (FWO: G.0209.11), the ‘Long Term Structural Methusalem Funding by the Flemish Government’, the IAP 7/05 Interuniversity Attraction Poles Programme – Belgian State – Belgian Science Policy, and the Fund for Scientific Research Flanders (FWO-Vlaanderen) in supplying financing of beam time at the DUBBLE beam line of the ESRF and travel costs and a postdoctoral fellowship for S.T. The authors acknowledge the assistance from D. Banerjee (XAS campaign 26-01-979) at DUBBLE. E. A. Redekop acknowledges the Marie Curie International Incoming Fellowship granted by the European Commission (Grant Agreement No. 301703). The authors also express their gratitude to V. Bliznuk for acquisition of the TEM images. Approved Most recent IF: 4.123
  Call Number c:irua:132315 Serial 4000
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Author Fedotov, S.S.; Khasanova, N.R.; Samarin, A.S.; Drozhzhin, O.A.; Batuk, D.; Karakulina, O.M.; Hadermann, J.; Abakumov, A.M.; Antipov, E.V.
  Title AVPO4F (A = Li, K): A 4 V Cathode Material for High-Power Rechargeable Batteries Type A1 Journal article
  Year 2016 Publication Chemistry of materials Abbreviated Journal Chem Mater
  Volume 28 Issue 28 Pages 411-415
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract A novel potassium-based fluoride-phosphate, KVPO4F, with a KTiOPO4 (KTP) type structure is synthesized and characterized. About 85% of potassium has been electrochemically extracted on oxidation producing a cathode material with attractive performance for Li-ion batteries. The material operates at the electrode potential near 4V vs Li/Li+ exhibiting a sloping voltage profile, extremely low polarization, small volume change of about 2% and excellent rate capability, maintaining more than 75% of the initial capacity at 40C discharge rate without significant fading.
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  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000368949900002 Publication Date 2016-01-04
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0897-4756 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 9.466 Times cited 46 Open Access (up)
  Notes The authors kindly thank Dr. S. N. Putilin for XRD measurements, Dr. O. A. Shlyakhtin for the assistance in cryochemical synthesis, Ph.D. students A. A. Sadovnikov and E. A. Karpukhina for SEM imaging and FTIR spectra respectively. The work was partly supported by Russian Science Foundation (grant 16-19-00190), Skoltech Center for Electrochemical Energy Storage and Moscow State University Devel-opment Program up to 2020. J. Hadermann, O.M. Karakulina and A.M. Abakumov acknowledge support from FWO under grant G040116N. Approved Most recent IF: 9.466
  Call Number c:irua:131583 Serial 4001
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Author Khalilov, U.; Yusupov, M.; Bogaerts, A.; Neyts, E.C.
  Title Selective Plasma Oxidation of Ultrasmall Si Nanowires Type A1 Journal article
  Year 2016 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
  Volume 120 Issue 120 Pages 472-477
  Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
  Abstract Device performance of Si|SiOx core-shell based nanowires critically depends on the exact control over the oxide thickness. Low-temperature plasma oxidation is a highly promising alternative to thermal oxidation allowing for improved control over the oxidation process, in particular for ultrasmall Si nanowires. We here elucidate the room temperature plasma oxidation mechanisms of ultrasmall Si nanowires using hybrid molecular dynamics / force-bias Monte Carlo simulations. We demonstrate how the oxidation and concurrent water formation mechanisms are a function of the oxidizing plasma species and we demonstrate how the resulting core-shell oxide thickness can be controlled through these species. A new mechanism of water formation is discussed in detail. The results provide a detailed atomic level explanation of the oxidation process of highly curved Si surfaces. These results point out a route toward plasma-based formation of ultrathin core-shell Si|SiOx nanowires at room temperature.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000368562200057 Publication Date 2015-12-21
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1932-7447 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 4.536 Times cited 3 Open Access (up)
  Notes U.K. and M.Y. gratefully acknowledge financial support from the Research Foundation – Flanders (FWO), Grants 12M1315N and 1200216N. This work was carried out in part using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen (UA), a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the UA. We thank Prof. A. C. T. van Duin for sharing the ReaxFF code. Approved Most recent IF: 4.536
  Call Number c:irua:130677 Serial 4002
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Author McCalla, E.; Abakumov, A.M.; Saubanere, M.; Foix, D.; Berg, E.J.; Rousse, G.; Doublet, M.-L.; Gonbeau, D.; Novak, P.; Van Tendeloo, G.; Dominko, R.; Tarascon, J.-M.
  Title Visualization of O-O peroxo-like dimers in high-capacity layered oxides for Li-ion batteries Type A1 Journal article
  Year 2015 Publication Science Abbreviated Journal Science
  Volume 350 Issue 350 Pages 1516-1521
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
  Abstract Lithium-ion (Li-ion) batteries that rely on cationic redox reactions are the primary energy source for portable electronics. One pathway toward greater energy density is through the use of Li-rich layered oxides. The capacity of this class of materials (>270 milliampere hours per gram) has been shown to be nested in anionic redox reactions, which are thought to form peroxo-like species. However, the oxygen-oxygen (O-O) bonding pattern has not been observed in previous studies, nor has there been a satisfactory explanation for the irreversible changes that occur during first delithiation. By using Li2IrO3 as a model compound, we visualize the O-O dimers via transmission electron microscopy and neutron diffraction. Our findings establish the fundamental relation between the anionic redox process and the evolution of the O-O bonding in layered oxides.
  Address College de France, Chimie du Solide et de l'Energie, FRE 3677, 11 Place Marcelin Berthelot, 75231 Paris Cedex 05, France. ALISTORE-European Research Institute, FR CNRS 3104, 80039 Amiens, France. Reseau sur le Stockage Electrochimique de l'Energie (RS2E), FR CNRS 3459, France. Sorbonne Universites-UPMC Univ Paris 06, 4 Place Jussieu, F-75005 Paris, France. jean-marie.tarascon@college-de-france.fr
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language English Wos 000366591100056 Publication Date 2015-12-17
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0036-8075 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 37.205 Times cited 281 Open Access (up)
  Notes E.M. thanks the Fonds de Recherche du Québec–Nature et Technologies and ALISTORE–European Research Institute for funding this work, as well as the European community I3 networks for funding the neutron scattering research trip. This work was also funded by the Slovenian Research Agency research program P2-0148. This work is partially based on experiments performed at the Institut Laue Langevin. We thank J. Rodriguez-Carvajal for help with neutron scattering experiments and for fruitful discussions. We also thank M. T. Sougrati for performing the Sn-Mössbauer measurements. Use of the Advanced Photon Source at Argonne National Laboratory was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under contract no. DE-AC02- 06CH11357. M.S. and M.-L.D. acknowledge high-performance computational resources from GENCI-CCRT/CINES (grant cmm6691). J.-M.T. acknowledges funding from the European Research Council (ERC) (FP/2014-2020)/ERC Grant-Project670116-ARPEMA. Approved Most recent IF: 37.205; 2015 IF: 33.611
  Call Number c:irua:130202 Serial 4005
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Author Covaci, L.; Berciu, M.
  Title Survival of the Dirac points in rippled graphene Type A1 Journal article
  Year 2008 Publication Physical Review Letters Abbreviated Journal Phys Rev Lett
  Volume 100 Issue 25 Pages 256405
  Keywords A1 Journal article; Electron Microscopy for Materials Science (EMAT);
  Abstract We study the effects of the rippling of a graphene sheet on quasiparticle dispersion. This is achieved using a generalization to the honeycomb lattice of the momentum average approximation, which is accurate for all coupling strengths and at all energies. We show that even though the position of the Dirac points may move and the Fermi speed can be renormalized significantly, quasiparticles with very long lifetimes survive near the Dirac points even for very strong couplings.
  Address Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada, V6T 1Z1
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language English Wos 000257230500047 Publication Date 2008-06-26
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0031-9007 ISBN Additional Links
  Impact Factor 8.462 Times cited 15 Open Access (up)
  Notes Approved Most recent IF: 8.462; 2008 IF: 7.180
  Call Number UA @ lucian @ Serial 4010
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