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Author Mueller, K.; Krause, F.F.; Béché, A.; Schowalter, M.; Galioit, V.; Loeffler, S.; Verbeeck, J.; Zweck, J.; Schattschneider, P.; Rosenauer, A.
  Title Atomic electric fields revealed by a quantum mechanical approach to electron picodiffraction Type A1 Journal article
  Year 2014 Publication Nature communications Abbreviated Journal Nat Commun
  Volume 5 Issue Pages 5653
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
  Abstract By focusing electrons on probes with a diameter of 50 pm, aberration-corrected scanning transmission electron microscopy (STEM) is currently crossing the border to probing subatomic details. A major challenge is the measurement of atomic electric fields using differential phase contrast (DPC) microscopy, traditionally exploiting the concept of a field- induced shift of diffraction patterns. Here we present a simplified quantum theoretical interpretation of DPC. This enables us to calculate the momentum transferred to the STEM probe from diffracted intensities recorded on a pixel array instead of conventional segmented bright- field detectors. The methodical development yielding atomic electric field, charge and electron density is performed using simulations for binary GaN as an ideal model system. We then present a detailed experimental study of SrTiO3 yielding atomic electric fields, validated by comprehensive simulations. With this interpretation and upgraded instrumentation, STEM is capable of quantifying atomic electric fields and high-contrast imaging of light atoms.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000347227700003 Publication Date (down) 2014-12-15
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 2041-1723; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 12.124 Times cited 197 Open Access
  Notes 246791 COUNTATOMS; 278510 VORTEX; Hercules; 312483 ESTEEM2; esteem2ta; ECASJO; Approved Most recent IF: 12.124; 2014 IF: 11.470
  Call Number UA @ lucian @ c:irua:122835UA @ admin @ c:irua:122835 Serial 166
Permanent link to this record
 

 
Author Shakouri, K.; Vasilopoulos, P.; Vargiamidis, V.; Peeters, F.M.
  Title Integer and half-integer quantum Hall effect in silicene: Influence of an external electric field and impurities Type A1 Journal article
  Year 2014 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 90 Issue 23 Pages 235423
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract The influence of silicene's strong spin-orbit interaction and of an external electric field E-z on the transport coefficients are investigated in the presence of a perpendicular magnetic field B. For finite E-z the spin and valley degeneracy of the Landau levels is lifted and leads to additional plateaus in the Hall conductivity, at half-integer values of 4e(2)/h, due to spin intra-Landau-level transitions that are absent in graphene. These plateaus are more sensitive to disorder and thermal broadening than the main plateaus, occurring at integral values of 4e(2)/h, when the Fermi level passes through the Landau levels. We also evaluate the Hall and longitudinal resistivities and critically contrast the results with those for graphene on a substrate.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000346377400004 Publication Date (down) 2014-12-15
  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 32 Open Access
  Notes ; Our work was supported by the Flemish Science Foundation (FWO-VI), the Methusalem Foundation of the Flemish Government, and the Canadian NSERC Grant No. OGP0121756. ; Approved Most recent IF: 3.836; 2014 IF: 3.736
  Call Number UA @ lucian @ c:irua:122771 Serial 1678
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Author Croitoru, M.D.; Buzdin, A.I.
  Title FFLO-wave-vector lock-in effect in quasi-1D superconductors Type A1 Journal article
  Year 2015 Publication Journal of superconductivity and novel magnetism Abbreviated Journal J Supercond Nov Magn
  Volume 28 Issue 28 Pages 1305-1308
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract We study the phase transition into the Fulde-Ferrell-Larkin-Ovchinnikov state in high magnetic field in quasi-one dimensional superconductors within the quasi-classical formalism, taking into account the interchain Josephson coupling and the paramagnetic spin splitting. We show that anomalies in the field-direction dependence of the upper critical field when the magnetic field length equals to the FFLO period, previously described in [29], are characterized by the lock-in effect of the FFLO modulation wave vector, which is governed by the magnetic length.
  Address
  Corporate Author Thesis
  Publisher Place of Publication New York, N.Y. Editor
  Language Wos 000352085700019 Publication Date (down) 2014-12-13
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1557-1939;1557-1947; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 1.18 Times cited 4 Open Access
  Notes ; We thank D. Jerome for useful discussions. We acknowledge the support by the French ANR program “ElectroVortex” and European NanoSC COST Action MP1201. M.D.C. acknowledges the support by the BELSPO Return to Belgium Grant. ; Approved Most recent IF: 1.18; 2015 IF: 0.909
  Call Number c:irua:125540 Serial 1187
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Author Guerrero, A.; Heidari, H.; Ripolles, T.S.; Kovalenko, A.; Pfannmöller, M.; Bals, S.; Kauffmann, L.-D.; Bisquert, J.; Garcia-Belmonte, G.
  Title Shelf life degradation of bulk heterojunction solar cells : intrinsic evolution of charge transfer complex Type A1 Journal article
  Year 2015 Publication Laser physics review Abbreviated Journal Adv Energy Mater
  Volume 5 Issue 5 Pages 1401997
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
  Abstract Achievement of long-term stability of organic photovoltaics is currently one of the major topics for this technology to reach maturity. Most of the techniques used to reveal degradation pathways are destructive and/or do not allow for real-time measurements in operating devices. Here, three different, nondestructive techniques able to provide real-time information, namely, film absorbance, capacitance-voltage (C-V), and impedance spectroscopy (IS), are combined over a period of 1 year using non-accelerated intrinsic degradation conditions. It is discerned between chemical modifications in the active layer, physical processes taking place in the bulk of the blend from those at the active layer/contact interfaces. In particular, it is observed that during the ageing experiment, the main source for device performance degradation is the formation of donor-acceptor charge-transfer complex (P3HT(center dot+)-PCBM center dot-) that acts as an exciton quencher. Generation of these radical species diminishes photocurrent and reduces open-circuit voltage by the creation of electronic defect states. Conclusions extracted from absorption, C-V, and IS measurements will be further supported by a range of other techniques such as atomic force microscopy, X-ray diffraction, and dark-field imaging of scanning transmission electron microscopy on ultrathin cross-sections.
  Address
  Corporate Author Thesis
  Publisher Place of Publication S.l. Editor
  Language Wos 000352708600013 Publication Date (down) 2014-12-12
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1614-6832; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 16.721 Times cited 30 Open Access OpenAccess
  Notes 287594 Sunflower; 335078 Colouratom; ECAS_Sara; (ROMEO:yellow; preprint:; postprint:restricted ; pdfversion:cannot); Approved Most recent IF: 16.721; 2015 IF: 16.146
  Call Number c:irua:126000 Serial 2994
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Author Lin, F.; Meng; Kukueva, E.; Mertens, M.; Van Doorslaer, S.; Bals, S.; Cool, P.
  Title New insights into the mesophase transformation of ethane-bridged PMOs by the influence of different counterions under basic conditions Type A1 Journal article
  Year 2015 Publication RSC advances Abbreviated Journal Rsc Adv
  Volume 5 Issue 5 Pages 5553-5562
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA)
  Abstract The counterions are of crucial importance in determining the mesostructure and morphology of ethanebridged PMO materials synthesized under basic conditions. By using CTABr as the surfactant, the final PMO materials show a 2-D hexagonal (p6mm) mesophase, while PMO materials with cubic (Pm (3) over barn ) mesostructure are obtained when CTACl or CTA(SO4)(1)/(2) are used. With gradually replacing CTABr by CTACl or CTA(SO4) (1)/(2) while keeping the total surfactant concentration constant, a clear p6mm to Pm (3) over barn 3n mesophase evolution process is observed. For a given gel composition, the mesophase of ethanebridged PMO materials can also be adjusted by the addition of different sodium salts. In short, the effect of the counterions on the mesophase can be attributed to the binding strength of the ions on the surfactant micelles, which follows the Hofmeister series (SO42- < Cl- < Br-< NO3- < SCN-). Furthermore, it is found that the hydrolysis and condensation rate of the organosilica precursor also plays an important role in the formation of the final mesostructure
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000347304900010 Publication Date (down) 2014-12-11
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 2046-2069; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 3.108 Times cited 6 Open Access Not_Open_Access
  Notes ; The Erasmus Mundus CONNEC program is acknowledged for PhD funding of F. L. Furthermore, the authors acknowledge support by the GOA-BOF project 'Optimization of the structureactivity relation in nanoporous materials', funded by the University of Antwerp. ; Approved Most recent IF: 3.108; 2015 IF: 3.840
  Call Number c:irua:123768 Serial 2317
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Author Ennaert, T.; Geboers, J.; Gobechiya, E.; Courtin, C.M.; Kurttepeli, M.; Houthoofd, K.; Kirschhock, C.E.A.; Magusin, P.C.M.M.; Bals, S.; Jacobs, P.A.; Sels, B.F.
  Title Conceptual frame rationalizing the self-stabilization of H-USY zeolites in hot liquid water Type A1 Journal article
  Year 2015 Publication ACS catalysis Abbreviated Journal Acs Catal
  Volume 5 Issue 5 Pages 754-768
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract The wide range of liquid-phase reactions required for the catalytic conversion of biomass compounds into new bioplatform molecules defines a new set of challenges for the development of active, selective, and stable catalysts. The potential of bifunctional Ru/H-USY catalysts for conversions in hot liquid water (HLW) is assessed in terms of physicochemical stability and long-term catalytic performance of acid sites and noble metal functionality, as probed by hydrolytic hydrogenation of cellulose. It is shown that zeolite desilication is the main zeolite degradation mechanism in HLW. USY zeolite stability depends on two main parameters, viz., framework and extra-framework aluminum content. The former protects the zeolite lattice by counteracting hydrolysis of framework bonds, and the latter, when located at the external crystal surface, prevents solubilization of the zeolite framework which is the result of its low water-solubility. Hence, the hot liquid water stability of commercial H-USY zeolites, in contrast to their steam stability, increased with decreasing Si/AI ratio. As a result, mildly steamed USY zeolites containing a high amount of both Al species exhibit the highest resistance to HLW. During an initial period of transformations, Al-rich zeolites form additional protective extra-framework Al species at the outer surface, self-stabilizing the framework. A critical bulk Si/AI ratio of 3 was determined whereby USY zeolites with a lower Si/AI ratio will self-stabilize over time. Besides, due to the initial transformation period, the accessibility of the catalytic active sites is extensively enhanced resulting in a material that is more stable and drastically more accessible to large substrates than the original zeolite. When these findings are applied in the hydrolytic hydrogenation of cellulose, unprecedented nearly quantitative hexitol yields were obtained with a stable catalytic system.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000349275300031 Publication Date (down) 2014-12-09
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 2155-5435;2155-5435; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 10.614 Times cited 65 Open Access OpenAccess
  Notes 335078 Colouratom; ECAS_Sara; (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); Approved Most recent IF: 10.614; 2015 IF: 9.312
  Call Number c:irua:125288 Serial 474
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Author da Silva, R.M.; Milošević, M.V.; Dominguez, D.; Peeters, F.M.; Albino Aguiar, J.
  Title Distinct magnetic signatures of fractional vortex configurations in multiband superconductors Type A1 Journal article
  Year 2014 Publication Applied physics letters Abbreviated Journal Appl Phys Lett
  Volume 105 Issue 23 Pages 232601
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract Vortices carrying fractions of a flux quantum are predicted to exist in multiband superconductors, where vortex core can split between multiple band-specific components of the superconducting condensate. Using the two-component Ginzburg-Landau model, we examine such vortex configurations in a two-band superconducting slab in parallel magnetic field. The fractional vortices appear due to the band-selective vortex penetration caused by different thresholds for vortex entry within each band-condensate, and stabilize near the edges of the sample. We show that the resulting fractional vortex configurations leave distinct fingerprints in the static measurements of the magnetization, as well as in ac dynamic measurements of the magnetic susceptibility, both of which can be readily used for the detection of these fascinating vortex states in several existing multiband superconductors. (C) 2014 AIP Publishing LLC.
  Address
  Corporate Author Thesis
  Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
  Language Wos 000346266000066 Publication Date (down) 2014-12-09
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0003-6951;1077-3118; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 3.411 Times cited 22 Open Access
  Notes ; This work was supported by the Brazilian science agencies CAPES (Grant No. PNPD 223038.003145/2011-00), CNPq (Grant Nos. 307552/2012-8, 141911/2012-3, and APV-4 02937/2013-9), and FACEPE (Grant Nos. APQ-0202-1.05/10 and BCT-0278-1.05/ 11), the Research Foundation Flanders (FWO-Vlaanderen), and by the CNPq-FWO cooperation programme (CNPq Grant No. 490297/2009-9). D.D. acknowledges support from CONICET, CNEA, and ANPCyT-PICT2011-1537. The authors thank A. A. Shanenko for extensive discussions on the topic. ; Approved Most recent IF: 3.411; 2014 IF: 3.302
  Call Number UA @ lucian @ c:irua:122775 Serial 742
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Author Retuerto, M.; Yin, Z.; Emge, T.J.; Stephens, P.W.; Li, M.R.; Sarkar, T.; Croft, M.C.; Ignatov, A.; Yuan, Z.; Zhang, S.J.; Jin, C.; Paria Sena, R.; Hadermann, J.; Kotliar, G.; Greenblatt, M.;
  Title Hole doping and structural transformation in CsTl1-xHgxCl3 Type A1 Journal article
  Year 2015 Publication Inorganic chemistry Abbreviated Journal Inorg Chem
  Volume 54 Issue 54 Pages 1066-1075
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract CsTlCl3 and CsTlF3 perovskites have been theoretically predicted to be superconductors when properly hole-doped. Both compounds have been previously prepared as pure compounds: CsTlCl3 in a tetragonal (I4/m) and a cubic (Fm3̅m) perovskite polymorph and CsTlF3 as a cubic perovskite (Fm3̅m). In this work, substitution of Tl in CsTlCl3 with Hg is reported, in an attempt to hole-dope the system and induce superconductivity. The whole series CsTl1xHgxCl3 (x = 0.0, 0.1, 0.2, 0.4, 0.6, and 0.8) was prepared. CsTl0.9Hg0.1Cl3 is tetragonal as the more stable phase of CsTlCl3. However, CsTl0.8Hg0.2Cl3 is already cubic with the space group Fm3̅m and with two different positions for Tl+ and Tl3+. For x = 0.4 and 0.5, solid solutions could not be formed. For x ≥ 0.6, the samples are primitive cubic perovskites with one crystallographic position for Tl+, Tl3+, and Hg2+. All of the samples formed are insulating, and there is no signature of superconductivity. X-ray absorption spectroscopy indicates that all of the samples have a mixed-valence state of Tl+ and Tl3+. Raman spectroscopy shows the presence of the active TlClTl stretching mode over the whole series and the intensity of the TlClHg mode increases with increasing Hg content. First-principle calculations confirmed that the phases are insulators in their ground state and that Hg is not a good dopant in the search for superconductivity in this system.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Easton, Pa Editor
  Language Wos 000348887400048 Publication Date (down) 2014-12-09
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0020-1669;1520-510X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 4.857 Times cited 5 Open Access
  Notes Approved Most recent IF: 4.857; 2015 IF: 4.762
  Call Number c:irua:124420 Serial 1476
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Author Zarenia, M.; Perali, A.; Neilson, D.; Peeters, F.M.
  Title Enhancement of electron-hole superfluidity in double few-layer graphene Type A1 Journal article
  Year 2014 Publication Scientific reports Abbreviated Journal Sci Rep-Uk
  Volume 4 Issue 4 Pages 7319
  Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
  Abstract We propose two coupled electron-hole sheets of few-layer graphene as a new nanostructure to observe superfluidity at enhanced densities and enhanced transition temperatures. For ABC stacked few-layer graphene we show that the strongly correlated electron-hole pairing regime is readily accessible experimentally using current technologies. We find for double trilayer and quadlayer graphene sheets spatially separated by a nano-thick hexagonal boron-nitride insulating barrier, that the transition temperature for electron-hole superfluidity can approach temperatures of 40 K.
  Address
  Corporate Author Thesis
  Publisher Nature Publishing Group Place of Publication London Editor
  Language Wos 000346272900001 Publication Date (down) 2014-12-08
  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 38 Open Access
  Notes ; We thank L. Benfatto, S. De Palo, and G. Senatore for helpful comments. This work was partially supported by the Flemish Science Foundation (FWO-Vl) and the European Science Foundation (POLATOM). ; Approved Most recent IF: 4.259; 2014 IF: 5.578
  Call Number UA @ lucian @ c:irua:122743 Serial 1062
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Author Deng, S.; Kurttepeli, M.; Cott, D.J.; Bals, S.; Detavernier, C.
  Title Porous nanostructured metal oxides synthesized through atomic layer deposition on a carbonaceous template followed by calcination 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 2642-2649
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
  Abstract Porous metal oxides with nano-sized features attracted intensive interest in recent decades due to their high surface area which is essential for many applications, e.g. Li ion batteries, photocatalysts, fuel cells and dye-sensitized solar cells. Various approaches have so far been investigated to synthesize porous nanostructured metal oxides, including self-assembly and template-assisted synthesis. For the latter approach, forests of carbon nanotubes are considered as particularly promising templates, with respect to their one-dimensional nature and the resulting high surface area. In this work, we systematically investigate the formation of porous metal oxides (Al2O3, TiO2, V2O5 and ZnO) with different morphologies using atomic layer deposition on multi-walled carbon nanotubes followed by post-deposition calcination. X-ray diffraction, scanning electron microscopy accompanied by X-ray energy dispersive spectroscopy and transmission electron microscopy were used for the investigation of morphological and structural transitions at the micro- and nano-scale during the calcination process. The crystallization temperature and the surface coverage of the metal oxides and the oxidation temperature of the carbon nanotubes were found to produce significant influence on the final morphology.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Cambridge Editor
  Language Wos 000348990500019 Publication Date (down) 2014-12-06
  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 23 Open Access OpenAccess
  Notes Fwo; 239865 Cocoon; 335078 Colouratoms; ECAS_Sara; (ROMEO:yellow; preprint:; postprint:restricted ; pdfversion:cannot); Approved Most recent IF: 8.867; 2015 IF: 7.443
  Call Number c:irua:125298 Serial 2673
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Author van der Stam, W.; Akkerman, Q.A.; Ke, X.; van Huis, M.A.; Bals, S.; de Donega, C.M.
  Title Solution-processable ultrathin size- and shape-controlled colloidal Cu2-xS nanosheets Type A1 Journal article
  Year 2015 Publication Chemistry of materials Abbreviated Journal Chem Mater
  Volume 27 Issue 27 Pages 283-291
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract Ultrathin two-dimensional (2D) nanosheets (NSs) possess extraordinary properties that are attractive for both fundamental studies and technological devices. Solution-based bottom-up methods are emerging as promising routes to produce free-standing NSs, but the synthesis of colloidal NSs with well-defined size and shape has remained a major challenge. In this work, we report a novel method that yields 2 nm thick colloidal Cu2-xS NSs with well-defined shape (triangular or hexagonal) and size (100 nm to 3 mu m). The key feature of our approach is the use of a synergistic interaction between halides (Br or Cl) and copper-thiolate metal-organic frameworks to create a template that imposes 2D constraints on the Cu-catalyzed C-S thermolysis, resulting in nucleation and growth of colloidal 2D Cu2-xS NSs. Moreover, the NS composition can be postsynthetically tailored by exploiting topotactic cation exchange reactions. This is illustrated by converting the Cu2-xS NSs into ZnS and CdS NSs while preserving their size and shape. The method presented here thus holds great promise as a route to solution-processable compositionally diverse ultrathin colloidal NSs with well-defined shape and size.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000348085300036 Publication Date (down) 2014-12-04
  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 68 Open Access OpenAccess
  Notes 335078 Colouratom; 246791 Countatoms; 312483 Esteem2; esteem2ta; ECASSara; (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); Approved Most recent IF: 9.466; 2015 IF: 8.354
  Call Number c:irua:123865 c:irua:123865 Serial 3052
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Author Liao, L.; Heylen, S.; Vallaey, B.; Keulemans, M.; Lenaerts, S.; Roeffaers, M.B.J.; Martens, J.A.
  Title Photocatalytic carbon oxidation with nitric oxide Type A1 Journal article
  Year 2015 Publication Applied catalysis : B : environmental Abbreviated Journal Appl Catal B-Environ
  Volume 166 Issue Pages 374-380
  Keywords A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
  Abstract The photocatalytic oxidation of carbon black on TiO2 using nitric oxide as an oxidizing agent was investigated. Layer-wise deposited carbon and TiO2 powder was illuminated with UVA light in the presence of NO at parts per million concentrations in dry and hydrated carrier gas at a temperature of 150 degrees C. Carbon was photocatalytically converted mainly into CO2, and NO mainly into N-2. Carbon oxidation rates of 7.2 mu g/h/mgTiO(2) were achieved in the presence of 3000 ppm NO. Under these experimental conditions in the absence of molecular oxygen, formation of surface nitrates causing TiO2 photocatalyst deactivation is suppressed. Addition of water enhances surface nitrate formation and catalyst deactivation. NO and carbon particulate matter are air pollutants emitted by diesel engines. Elimination of soot collected on a diesel particulate filter through oxidation is a demanding reaction requiring temperatures in excess of 250 degrees C. The present study opens perspectives for a low-temperature regeneration strategy for the diesel particulate filter that simultaneously performs DeNO(x) reactions. (C) 2014 Elsevier B.V. All rights reserved.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000348753400042 Publication Date (down) 2014-12-03
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0926-3373 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 9.446 Times cited 5 Open Access
  Notes ; This work was supported by long-term structural funding by the Flemish government (Methusalem). ; Approved Most recent IF: 9.446; 2015 IF: 7.435
  Call Number UA @ admin @ c:irua:123858 Serial 5977
Permanent link to this record
 

 
Author Çakir, D.; Otalvaro, D.M.; Brocks, G.
  Title Magnetoresistance in multilayer fullerene spin valves: A first-principles study Type A1 Journal article
  Year 2014 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 90 Issue 24 Pages 245404
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract Carbon-based molecular semiconductors are explored for application in spintronics because their small spinorbit coupling promises long spin lifetimes. We calculate the electronic transport from first principles through spin valves comprising bi-and tri-layers of the fullerene molecules C-60 and C-70, sandwiched between two Fe electrodes. The spin polarization of the current, and the magnetoresistance depend sensitively on the interactions at the interfaces between the molecules and the metal surfaces. They are much less affected by the thickness of the molecular layers. A high current polarization (CP > 90%) and magnetoresistance (MR > 100%) at small bias can be attained using C-70 layers. In contrast, the current polarization and the magnetoresistance at small bias are vanishingly small for C-60 layers. Exploiting a generalized Julliere model we can trace the differences in spin-dependent transport between C-60 and C-70 layers to differences between the molecule-metal interface states. These states also allow one to interpret the current polarization and the magnetoresistance as a function of the applied bias voltage.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000345875200005 Publication Date (down) 2014-12-02
  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 13 Open Access
  Notes ; ; Approved Most recent IF: 3.836; 2014 IF: 3.736
  Call Number UA @ lucian @ c:irua:122177 Serial 1928
Permanent link to this record
 

 
Author Sathiya, M.; Abakumov, A.M.; Foix, D.; Rousse, G.; Ramesha, K.; Saubanère, M.; Doublet, M. .; Vezin, H.; Laisa, C.P.; Prakash, A.S.; Gonbeau, D.; Van Tendeloo, G.; Tarascon, J.M.
  Title Origin of voltage decay in high-capacity layered oxide electrodes Type A1 Journal article
  Year 2015 Publication Nature materials Abbreviated Journal Nat Mater
  Volume 14 Issue 14 Pages 230-238
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract Although Li-rich layered oxides (Li1+xNiyCozMn1−x−y−zO2 > 250 mAh g−1) are attractive electrode materials providing energy densities more than 15% higher than todays commercial Li-ion cells, they suffer from voltage decay on cycling. To elucidate the origin of this phenomenon, we employ chemical substitution in structurally related Li2RuO3 compounds. Li-rich layered Li2Ru1−yTiyO3 phases with capacities of ~240 mAh g−1 exhibit the characteristic voltage decay on cycling. A combination of transmission electron microscopy and X-ray photoelectron spectroscopy studies reveals that the migration of cations between metal layers and Li layers is an intrinsic feature of the chargedischarge process that increases the trapping of metal ions in interstitial tetrahedral sites. A correlation between these trapped ions and the voltage decay is established by expanding the study to both Li2Ru1−ySnyO3 and Li2RuO3; the slowest decay occurs for the cations with the largest ionic radii. This effect is robust, and the finding provides insights into new chemistry to be explored for developing high-capacity layered electrodes that evade voltage decay.
  Address
  Corporate Author Thesis
  Publisher Place of Publication London Editor
  Language Wos 000348600200024 Publication Date (down) 2014-12-01
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1476-1122;1476-4660; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 39.737 Times cited 395 Open Access
  Notes 246791 Countatoms; 312483 Esteem2; esteem2_ta Approved Most recent IF: 39.737; 2015 IF: 36.503
  Call Number c:irua:132555 c:irua:132555 Serial 2528
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Author Zha, G.-Q.; Peeters, F.M.; Zhou, S.-P.
  Title Vortex-antivortex dynamics in mesoscopic symmetric and asymmetric superconducting loops with an applied ac current Type A1 Journal article
  Year 2014 Publication Europhysics letters Abbreviated Journal Epl-Europhys Lett
  Volume 108 Issue 5 Pages 57001
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract In the framework of the time-dependent Ginzburg-Landau formalism, we study the dynamics of vortex-antivortex (V-Av) pairs in mesoscopic symmetric and asymmetric superconducting loops under an applied ac current. In contrast to the case of a constant biasing dc current, the process of the V-Av collision and annihilation is strongly affected by the time-periodic ac signal. As the direction of the applied ac current is reversed, the existed V-Av pair moves backward and then collides with a new created Av-V pair in a symmetric loop. In the presence of an appropriate external magnetic field, a novel sinusoidal-like oscillatory mode of the magnetization curve is observed, and the periodic dynamical process of the V-Av annihilation occurs in both branches of the sample. Moreover, for the asymmetric sample with an off-centered hole the creation point of the V-Av pair shifts away from the center of the sample, and the creation and annihilation dynamics of V-Av pairs turns out to be very different from the symmetric case. Copyright (C) EPLA, 2014
  Address
  Corporate Author Thesis
  Publisher Place of Publication Paris Editor
  Language Wos 000346792400027 Publication Date (down) 2014-11-28
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0295-5075;1286-4854; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 1.957 Times cited 4 Open Access
  Notes ; We are grateful to GOLIBJON BERDIYOROV for useful discussions. This work was supported by NSF China under Grant Nos. 61371020 and 61271163, by Visiting Scholar Program of Shanghai Municipal Education Commission, by Innovation Program of Shanghai Municipal Education Commission under Grant No. 13YZ006, and by Flemish Science Foundation (FWO-Vl). ; Approved Most recent IF: 1.957; 2014 IF: 2.095
  Call Number UA @ lucian @ c:irua:122800 Serial 3851
Permanent link to this record
 

 
Author Morozov, V.A.; Raskina, M.V.; Lazoryak, B.I.; Meert, K.W.; Korthout, K.; Smet, P.F.; Poelman, D.; Gauquelin, N.; Verbeeck, J.; Abakumov, A.M.; Hadermann, J.;
  Title Crystal Structure and Luminescent Properties of R2-xEux(MoO4)(3) (R = Gd, Sm) Red Phosphors Type A1 Journal article
  Year 2014 Publication Chemistry of materials Abbreviated Journal Chem Mater
  Volume 26 Issue 24 Pages 7124-7136
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract The R-2(MoO4)(3) (R = rare earth elements) molybdates doped with Eu3+ cations are interesting red-emitting materials for display and solid-state lighting applications. The structure and luminescent properties of the R2-xEux(MoO4)(3) (R = Gd, Sm) solid solutions have been investigated as a function of chemical composition and preparation conditions. Monoclinic (alpha) and orthorhombic (beta') R2-xEux(MoO4)(3) (R = Gd, Sm; 0 <= x <= 2) modifications were prepared by solid-state reaction, and their structures were investigated using synchrotron powder X-ray diffraction and transmission electron microscopy. The pure orthorhombic beta'-phases could be synthesized only by quenching from high temperature to room temperature for Gd2-xEux(MoO4)(3) in the Eu3+-rich part (x > 1) and for all Sm2-xEux(MoO4)(3) solid solutions. The transformation from the alpha-phase to the beta'-phase results in a notable increase (similar to 24%) of the unit cell volume for all R2-xEux(MoO4)(3) (R = Sm, Gd) solid solutions. The luminescent properties of all R2-xEux(MoO4)(3) (R = Gd, Sm; 0 <= x <= 2) solid solutions were measured, and their optical properties were related to their structural properties. All R2-xEux(MoO4)(3) (R = Gd, Sm; 0 <= x <= 2) phosphors emit intense red light dominated by the D-5(0)-> F-7(2) transition at similar to 616 nm. However, a change in the multiplet splitting is observed when switching from the monoclinic to the orthorhombic structure, as a consequence of the change in coordination polyhedron of the luminescent ion from RO8 to RO7 for the alpha- and beta'-modification, respectively. The Gd2-xEux(MoO4)(3) solid solutions are the most efficient emitters in the range of 0 < x < 1.5, but their emission intensity is comparable to or even significantly lower than that of Sm2-xEux(MoO4)(3) for higher Eu3+ concentrations (1.5 <= x <= 1.75). Electron energy loss spectroscopy (EELS) measurements revealed the influence of the structure and element content on the number and positions of bands in the ultraviolet-visible-infrared regions of the EELS spectrum.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000347139700027 Publication Date (down) 2014-11-27
  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 24 Open Access
  Notes Fwo G039211n; G004413n; 278510 Vortex ECASJO_; Approved Most recent IF: 9.466; 2014 IF: 8.354
  Call Number UA @ lucian @ c:irua:122829UA @ admin @ c:irua:122829 Serial 558
Permanent link to this record
 

 
Author Bal, K.M.; Neyts, E.C.
  Title On the time scale associated with Monte Carlo simulations Type A1 Journal article
  Year 2014 Publication The journal of chemical physics Abbreviated Journal J Chem Phys
  Volume 141 Issue 20 Pages 204104
  Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
  Abstract Uniform-acceptance force-bias Monte Carlo (fbMC) methods have been shown to be a powerful technique to access longer timescales in atomistic simulations allowing, for example, phase transitions and growth. Recently, a new fbMC method, the time-stamped force-bias Monte Carlo (tfMC) method, was derived with inclusion of an estimated effective timescale; this timescale, however, does not seem able to explain some of the successes the method. In this contribution, we therefore explicitly quantify the effective timescale tfMC is able to access for a variety of systems, namely a simple single-particle, one-dimensional model system, the Lennard-Jones liquid, an adatom on the Cu(100) surface, a silicon crystal with point defects and a highly defected graphene sheet, in order to gain new insights into the mechanisms by which tfMC operates. It is found that considerable boosts, up to three orders of magnitude compared to molecular dynamics, can be achieved for solid state systems by lowering of the apparent activation barrier of occurring processes, while not requiring any system-specific input or modifications of the method. We furthermore address the pitfalls of using the method as a replacement or complement of molecular dynamics simulations, its ability to explicitly describe correct dynamics and reaction mechanisms, and the association of timescales to MC simulations in general.
  Address
  Corporate Author Thesis
  Publisher Place of Publication New York, N.Y. Editor
  Language Wos 000345641400005 Publication Date (down) 2014-11-26
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0021-9606;1089-7690; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 2.965 Times cited 26 Open Access
  Notes Approved Most recent IF: 2.965; 2014 IF: 2.952
  Call Number UA @ lucian @ c:irua:120667 Serial 2459
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Author Yalcin, A.O.; Goris, B.; van Dijk-Moes, R.J.A.; Fan, Z.; Erdamar, A.K.; Tichelaar, F.D.; Vlugt, T.J.H.; Van Tendeloo, G.; Bals, S.; Vanmaekelbergh, D.; Zandbergen, H.W.; van Huis, M.A.;
  Title Heat-induced transformation of CdSe-CdS-ZnS coremultishell quantum dots by Zn diffusion into inner layers Type A1 Journal article
  Year 2015 Publication Chemical communications Abbreviated Journal Chem Commun
  Volume 51 Issue 51 Pages 3320-3323
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract In this work, we investigate the thermal evolution of CdSeCdSZnS coremultishell quantum dots (QDs) in situ using transmission electron microscopy (TEM). Starting at a temperature of approximately 250 °C, Zn diffusion into inner layers takes place together with simultaneous evaporation of particularly Cd and S. As a result of this transformation, CdxZn1−xSeCdyZn1−yS coreshell QDs are obtained.
  Address
  Corporate Author Thesis
  Publisher Place of Publication London Editor
  Language Wos 000349325000004 Publication Date (down) 2014-11-21
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1359-7345;1364-548X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 6.319 Times cited 21 Open Access OpenAccess
  Notes 262348 Esmi; Fwo; 246791 Countatoms; 335078 Colouratom; ECAS_Sara; (ROMEO:yellow; preprint:; postprint:restricted ; pdfversion:cannot); Approved Most recent IF: 6.319; 2015 IF: 6.834
  Call Number c:irua:132582 Serial 1412
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Author N. Gauquelin, E. Benckiser, M. K. Kinyanjui, M. Wu, Y. Lu, G. Christiani, G. Logvenov, H.-U. Habermeier, U. Kaiser, B. Keimer, and G. A. Botton
  Title Atomically resolved EELS mapping of the interfacial structure of epitaxially strained LaNiO3/LaAlO3 superlattices Type A1 Journal Article
  Year 2014 Publication Physical Review B Abbreviated Journal
  Volume 90 Issue Pages 195140
  Keywords A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ;
  Abstract The interfacial atomic structure of a metallic LaNiO3/LaAlO3 superlattice grown on a LaSrAlO4 substrate was

investigated using a combination of atomically resolved electron energy loss spectroscopy (EELS) at the Al K,

Al L2,3, Sr L2,3, Ni L2,3, La M4,5, and O K edges as well as hybridization mapping of selected features of the O

K-edge fine structure.We observe an additional La1−xSrxAl1−yNiyO3 layer at the substrate-superlattice interface,

possibly linked to diffusion of Al and Sr into the growing film or a surface reconstruction due to Sr segregation.

The roughness of the LaNiO3/LaAlO3 interfaces is found to be on average around one pseudocubic unit cell. The

O K-edge EELS spectra revealed reduced spectral weight of the prepeak derived from Ni-O hybridized states in

the LaNiO3 layers. We rule out oxygen nonstoichiometry of the LaNiO3 layers and discuss changes in the Ni-O

hybridization due to heterostructuring as possible origin.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000345467000003 Publication Date (down) 2014-11-20
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN ISBN Additional Links
  Impact Factor Times cited 17 Open Access
  Notes Approved Most recent IF: NA
  Call Number EMAT @ emat @ Serial 4544
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Author Sankaran, K.; Clima, S.; Mees, M.; Pourtois, G.
  Title Exploring alternative metals to Cu and W for interconnects applications using automated first-principles simulations Type A1 Journal article
  Year 2015 Publication ECS journal of solid state science and technology Abbreviated Journal Ecs J Solid State Sc
  Volume 4 Issue 4 Pages N3127-N3133
  Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
  Abstract The bulk properties of elementary metals and copper based binary alloys have been investigated using automated first-principles simulations to evaluate their potential to replace copper and tungsten as interconnecting wires in the coming CMOS technology nodes. The intrinsic properties of the screened candidates based on their cohesive energy and on their electronic properties have been used as a metrics to reflect their resistivity and their sensitivity to electromigration. Using these values, the 'performances' of the alloys have been benchmarked with respect to the Cu and W ones. It turns out that for some systems, alloying Cu with another element leads to a reduced tendency to electromigration. This is however done at the expense of a decrease of the conductivity of the alloy with respect to the bulk metal. (C) 2014 The Electrochemical Society. All rights reserved.
  Address
  Corporate Author Thesis
  Publisher Electrochemical society Place of Publication Pennington (N.J.) Editor
  Language Wos 000349547900018 Publication Date (down) 2014-11-19
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 2162-8769;2162-8777; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 1.787 Times cited 19 Open Access
  Notes Approved Most recent IF: 1.787; 2015 IF: 1.558
  Call Number c:irua:125296 Serial 1150
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Author Guerrero, A.; Pfannmöller, M.; Kovalenko, A.; Ripolles, T.S.; Heidari, H.; Bals, S.; Kaufmann, L.-D.; Bisquert, J.; Garcia-Belmonte, G.
  Title Nanoscale mapping by electron energy-loss spectroscopy reveals evolution of organic solar cell contact selectivity Type A1 Journal article
  Year 2015 Publication Organic electronics: physics, materials, applications Abbreviated Journal Org Electron
  Volume 16 Issue 16 Pages 227-233
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract Organic photovoltaic (OPV) devices are on the verge of commercialization being long-term stability a key challenge. Morphology evolution during lifetime has been suggested to be one of the main pathways accounting for performance degradation. There is however a lack of certainty on how specifically the morphology evolution relates to individual electrical parameters on operating devices. In this work a case study is created based on a thermodynamically unstable organic active layer which is monitored over a period of one year under non-accelerated degradation conditions. The morphology evolution is revealed by compositional analysis of ultrathin cross-sections using nanoscale imaging in scanning transmission electron microscopy (STEM) coupled with electron energy-loss spectroscopy (EELS). Additionally, devices are electrically monitored in real-time using the non-destructive electrical techniques capacitance-voltage (C-V) and Impedance Spectroscopy (IS). By comparison of imaging and electrical techniques the relationship between nanoscale morphology and individual electrical parameters of device operation can be conclusively discerned. It is ultimately observed how the change in the cathode contact properties occurring after the migration of fullerene molecules explains the improvement in the overall device performance. (C) 2014 Elsevier B.V. All rights reserved.
  Address
  Corporate Author Thesis
  Publisher Place of Publication London Editor
  Language Wos 000345649500029 Publication Date (down) 2014-11-17
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1566-1199; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 3.399 Times cited 24 Open Access OpenAccess
  Notes 287594 Sunflower; 335078 Colouratom; ECAS_Sara; (ROMEO:green; preprint:; postprint:can ; pdfversion:cannot); Approved Most recent IF: 3.399; 2015 IF: 3.827
  Call Number c:irua:122169 Serial 2267
Permanent link to this record
 

 
Author Çakir, D.; Sahin, H.; Peeters, F.M.
  Title Tuning of the electronic and optical properties of single-layer black phosphorus by strain Type A1 Journal article
  Year 2014 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 90 Issue 20 Pages 205421
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract Using first principles calculations we showed that the electronic and optical properties of single-layer black phosphorus (BP) depend strongly on the applied strain. Due to the strong anisotropic atomic structure of BP, its electronic conductivity and optical response are sensitive to the magnitude and the orientation of the applied strain. We found that the inclusion of many body effects is essential for the correct description of the electronic properties of monolayer BP; for example, while the electronic gap of strainless BP is found to be 0.90 eV by using semilocal functionals, it becomes 2.31 eV when many-body effects are taken into account within the G(0)W(0) scheme. Applied tensile strain was shown to significantly enhance electron transport along zigzag direction of BP. Furthermore, biaxial strain is able to tune the optical band gap of monolayer BP from 0.38 eV (at -8% strain) to 2.07 eV (at 5.5%). The exciton binding energy is also sensitive to the magnitude of the applied strain. It is found to be 0.40 eV for compressive biaxial strain of -8%, and it becomes 0.83 eV for tensile strain of 4%. Our calculations demonstrate that the optical response of BP can be significantly tuned using strain engineering which appears as a promising way to design novel photovoltaic devices that capture a broad range of solar spectrum.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000345642000015 Publication Date (down) 2014-11-17
  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 219 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-long Fellowship. D.C. is supported by a FWO Pegasus-short Marie Curie Fellowship. ; Approved Most recent IF: 3.836; 2014 IF: 3.736
  Call Number UA @ lucian @ c:irua:122203 Serial 3752
Permanent link to this record
 

 
Author Esfahani, D.N.; Covaci, L.; Peeters, F.M.
  Title Nonlinear response to electric field in extended Hubbard models Type A1 Journal article
  Year 2014 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 90 Issue 20 Pages 205121
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract The electric-field response of a one-dimensional ring of interacting fermions, where the interactions are described by the extended Hubbard model, is investigated. By using an accurate real-time propagation scheme based on the Chebyshev expansion of the evolution operator, we uncover various nonlinear regimes for a range of interaction parameters that allows modeling of metallic and insulating (either charge density wave or spin density wave insulators) rings. The metallic regime appears at the phase boundary between the two insulating phases and provides the opportunity to describe either weakly or strongly correlated metals. We find that the fidelity susceptibility of the ground state as a function of magnetic flux piercing the ring provides a very good measure of the short-time response. Even completely different interacting regimes behave in a similar manner at short time scales as long as the ground-state fidelity susceptibility is the same. Depending on the strength of the electric field we find various types of responses: persistent currents in the insulating phase, a dissipative regime, or damped Bloch-like oscillations with varying frequencies or even irregular in nature. Furthermore, we also consider the dimerization of the ring and describe the response of a correlated band insulator. In this case the distribution of the energy levels is more clustered and the Bloch-like oscillations become even more irregular.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000345423300002 Publication Date (down) 2014-11-15
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 3.836 Times cited 3 Open Access
  Notes ; This work was supported by the Flemish Science Foundation (Fonds Wetenschappelijk Onderzoek – FWO) and the Methusalem program of the Flemish government. One of us (L. C.) receives support as a postdoctoral fellow of the FWO. ; Approved Most recent IF: 3.836; 2014 IF: 3.736
  Call Number UA @ lucian @ c:irua:122204 Serial 2355
Permanent link to this record
 

 
Author Zaikina, J.V.; Batuk, M.; Abakumov, A.M.; Navrotsky, A.; Kauziarich, S.M.
  Title Facile synthesis of Ba1-xKxFe2As2 superconductors via hydride route Type A1 Journal article
  Year 2014 Publication Journal of the American Chemical Society Abbreviated Journal J Am Chem Soc
  Volume 136 Issue 48 Pages 16932-16939
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract We have developed a fast, easy, and scalable synthesis method for Ba1xKxFe2As2 (0 ≤ x ≤ 1) superconductors using hydrides BaH2 and KH as a source of barium and potassium metals. Synthesis from hydrides provides better mixing and easier handling of the starting materials, consequently leading to faster reactions and/or lower synthesis temperatures. The reducing atmosphere provided by the evolved hydrogen facilitates preparation of oxygen-free powders. By a combination of methods we have shown that Ba1xKxFe2As2 obtained via hydride route has the same characteristics as when it is prepared by traditional solid-state synthesis. Refinement from synchrotron powder X-ray diffraction data confirms a linear dependence of unit cell parameters upon K content as well as the tetragonal to orthorhombic transition at low temperatures for compositions with x < 0.2. Magnetic measurements revealed dome-like dependence of superconducting transition temperature Tc upon K content with a maximum of 38 K for x close to 0.4. Electron diffraction and high-resolution high-angle annular dark-field scanning transmission electron microscopy indicates an absence of Ba/K ordering, while local inhomogeneity in the Ba/K distribution takes place at a scale of several angstroms along [110] crystallographic direction.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Washington, D.C. Editor
  Language Wos 000345883900040 Publication Date (down) 2014-11-11
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0002-7863;1520-5126; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 13.858 Times cited 13 Open Access
  Notes Approved Most recent IF: 13.858; 2014 IF: 12.113
  Call Number UA @ lucian @ c:irua:121331 Serial 1169
Permanent link to this record
 

 
Author Prodi, A.; Daoud-Aladine, A.; Gozzo, F.; Schmitt, B.; Lebedev, O.; Van Tendeloo, G.; Gilioli, E.; Bolzoni, F.; Aruga-Katori, H.; Takagi, H.; Marezio, M.; Gauzzi, A.;
  Title Commensurate structural modulation in the charge- and orbitally ordered phase of the quadruple perovskite (NaMn3)Mn4O12 Type A1 Journal article
  Year 2014 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 90 Issue 18 Pages 180101
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract By means of synchrotron x-ray and electron diffraction, we studied the structural changes at the charge order transition T-CO = 176 K in the mixed-valence quadruple perovskite (NaMn3)Mn4O12. Below T-CO we find satellite peaks indicating a commensurate structural modulation with the same propagation vector q = ( 1/2,0,-1/2) of the CE magnetic structure that orders at low temperatures, similarly to the case of simple perovskites such as La0.5Ca0.5MnO3. In the present case, the modulated structure, together with the observation of a large entropy change at T-CO, gives evidence of a rare case of full Mn3+/Mn4+ charge and orbital order, consistent with the Goodenough-Kanamori model.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000344915100001 Publication Date (down) 2014-11-10
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 3.836 Times cited 11 Open Access
  Notes Approved Most recent IF: 3.836; 2014 IF: 3.736
  Call Number UA @ lucian @ c:irua:122097 Serial 406
Permanent link to this record
 

 
Author Grujić, M.M.; Tadić, M.Z.; Peeters, F.M.
  Title Orbital magnetic moments in insulating Dirac systems : impact on magnetotransport in graphene van der Waals heterostructures Type A1 Journal article
  Year 2014 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 90 Issue 20 Pages 205408
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract In honeycomb Dirac systems with broken inversion symmetry, orbital magnetic moments coupled to the valley degree of freedom arise due to the topology of the band structure, leading to valley-selective optical dichroism. On the other hand, in Dirac systems with prominent spin-orbit coupling, similar orbital magnetic moments emerge as well. These moments are coupled to spin, but otherwise have the same functional form as the moments stemming from spatial inversion breaking. After reviewing the basic properties of these moments, which are relevant for a whole set of newly discovered materials, such as silicene and germanene, we study the particular impact that these moments have on graphene nanoengineered barriers with artificially enhanced spin-orbit coupling. We examine transmission properties of such barriers in the presence of a magnetic field. The orbital moments are found to manifest in transport characteristics through spin-dependent transmission and conductance, making them directly accessible in experiments. Moreover, the Zeeman-type effects appear without explicitly incorporating the Zeeman term in the models, i.e., by using minimal coupling and Peierls substitution in continuum and the tight-binding methods, respectively. We find that a quasiclassical view is able to explain all the observed phenomena.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000344915800009 Publication Date (down) 2014-11-10
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 3.836 Times cited 5 Open Access
  Notes ; This work was supported by the Ministry of Education, Science and Technological Development (Serbia), and the Fonds Wetenschappelijk Onderzoek (Belgium). ; Approved Most recent IF: 3.836; 2014 IF: 3.736
  Call Number UA @ lucian @ c:irua:122141 Serial 2497
Permanent link to this record
 

 
Author Miglio, A.; Saniz, R.; Waroquiers, D.; Stankovski, M.; Giantomassi, M.; Hautier, G.; Rignanese, G.-M.; Gonze, X.
  Title Computed electronic and optical properties of SnO2 under compressive stress Type A1 Journal article
  Year 2014 Publication Optical materials Abbreviated Journal Opt Mater
  Volume 38 Issue Pages 161-166
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract We consider the effects of three different types of applied compressive stress on the structural, electronic and optical properties of rutile SnO2. We use standard density functional theory (OFT) to determine the structural parameters. The effective masses and the electronic band gap, as well as their stress derivatives, are computed within both DFT and many-body perturbation theory (MBPT). The stress derivatives for the SnO2 direct band gap are determined to be 62, 38 and 25 meV/GPa within MBPT for applied hydrostatic, biaxial and uniaxial stress, respectively. Compared to DFT, this is a clear improvement with respect to available experimental data. We also estimate the exciton binding energies and their stress coefficients and compute the absorption spectrum by solving the Bethe-Salpeter equation. (C) 2014 Elsevier B.V. All rights reserved.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Amsterdam Editor
  Language Wos 000346228800028 Publication Date (down) 2014-11-08
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0925-3467; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 2.238 Times cited 6 Open Access
  Notes ; This work was supported by the FRS-FNRS through a FRIA grant (D.W.) and a FNRS grant (G.H.). This work was also supported by the IWT Project Number 080023 (ISIMADE), the Region Wallonne through WALL-ETSF project Number 816849, the EU-FP7 HT4TCOS Grant No. PCIG11-GA-2912-321988, the FRS-FNRS through contracts FRFC Number 2.4.589.09.F and AIXPHO (PDR Grant T-0238.13). The authors would like to thank Yann Pouillon and Jean-Michel Beuken for their valuable technical support and help with the test and build system of ABINIT. Computational resources have been provided by the supercomputing facilities of the Universite catholique de Louvain (CISM/UCL) and the Consortium des Equipements de Calcul Intensif en Federation Wallonie Bruxelles (CECI) funded by the Fonds de la Recherche Scientifique de Belgique (FRS-FNRS) under Grant No. 2.5020.11. ; Approved Most recent IF: 2.238; 2014 IF: 1.981
  Call Number UA @ lucian @ c:irua:122747 Serial 460
Permanent link to this record
 

 
Author Buffière, M.; Brammertz, G.; Batuk, M.; Verbist, C.; Mangin, D.; Koble, C.; Hadermann, J.; Meuris, M.; Poortmans, J.
  Title Microstructural analysis of 9.7% efficient Cu2ZnSnSe4 thin film solar cells Type A1 Journal article
  Year 2014 Publication Applied physics letters Abbreviated Journal Appl Phys Lett
  Volume 105 Issue 18 Pages 183903
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract This work presents a detailed analysis of the microstructure and the composition of our record Cu 2ZnSnSe4 (CZTSe)-CdS-ZnO solar cell with a total area efficiency of 9.7%. The average composition of the CZTSe crystallites is Cu 1.94 Zn 1.12Sn0.95Se3.99. Large crystals of ZnSe secondary phase (up to 400 nm diameter) are observed at the voids between the absorber and the back contact, while smaller ZnSe domains are segregated at the grain boundaries and close to the surface of the CZTSe grains. An underlying layer and some particles of Cu xSe are observed at the Mo-MoSe2-Cu2ZnSnSe4 interface. The free surface of the voids at the back interface is covered by an amorphous layer containing Cu, S, O, and C, while the presence of Cd, Na, and K is also observed in this region.
  Address
  Corporate Author Thesis
  Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
  Language Wos 000345000000086 Publication Date (down) 2014-11-08
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0003-6951;1077-3118; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 3.411 Times cited 17 Open Access
  Notes Approved Most recent IF: 3.411; 2014 IF: 3.302
  Call Number UA @ lucian @ c:irua:121329 Serial 2038
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Author Buffière, M.; Zaghi, A.E.; Lenaers, N.; Batuk, M.; Khelifi, S.; Drijkoningen, J.; Hamon, J.; Stesmans, A.; Kepa, J.; Afanas’ev, V.V.; Hadermann, J.; D’Haen, J.; Manca, J.; Vleugels, J.; Meuris, M.; Poortmans, J.;
  Title Effect of binder content in Cu-In-Se precursor ink on the physical and electrical properties of printed CuInSe2 solar cells Type A1 Journal article
  Year 2014 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
  Volume 118 Issue 47 Pages 27201-27209
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
  Abstract Printed chalcopyrite thin films have attracted considerable attention in recent years due to their potential in the high-throughput production of photovoltaic devices. To improve the homogeneity of printed CuInSe2 (CISe) layers, chemical additives such as binder can be added to the precursor ink. In this contribution, we investigate the influence of the dicyandiamide (DCDA) content, used as a binder in the precursor ink, on the physical and electrical properties of printed CISe solar cells. It is shown that the use of the binder leads to a dense absorber, composed of large CISe grains close to the surface, while the bulk of the layer consists of CISe crystallites embedded in a CuxS particle based matrix, resulting from the limited sintering of the precursor in this region. The expected additional carbon contamination of the CISe layer due to the addition of the binder appears to be limited, and the optical properties of the CISe layer are similar to the reference sample without additive. The electrical characterization of the corresponding CISe/CdS solar cells shows a degradation of the efficiency of the devices, due to a modification in the predominant recombination mechanisms and a limitation of the space charge region width when using the binder; both effects could be explained by the inhomogeneity of the bulk of the CISe absorber and high defect density at the CISe/CuxS-based matrix interface.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Washington, D.C. Editor
  Language Wos 000345722400003 Publication Date (down) 2014-11-06
  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 4 Open Access
  Notes Approved Most recent IF: 4.536; 2014 IF: 4.772
  Call Number UA @ lucian @ c:irua:121332 Serial 801
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Author Lukyanchuk, I.; Vinokur, V.M.; Rydh, A.; Xie, R.; Milošević, M.V.; Welp, U.; Zach, M.; Xiao, Z.L.; Crabtree, G.W.; Bending, S.J.; Peeters, F.M.; Kwok, W.K.
  Title Rayleigh instability of confined vortex droplets in critical superconductors Type A1 Journal article
  Year 2015 Publication Nature physics Abbreviated Journal Nat Phys
  Volume 11 Issue 11 Pages 21-25
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract Depending on the Ginzburg-Landau parameter kappa, superconductors can either be fully diamagnetic if kappa < 1/root 2 (type I superconductors) or allow magnetic flux to penetrate through Abrikosov vortices if kappa > 1/root 2 (type II superconductors; refs 1,2). At the Bogomolny critical point, kappa = kappa(c) = 1/root 2, a state that is infinitely degenerate with respect to vortex spatial configurations arises(3,4). Despite in-depth investigations of conventional type I and type II superconductors, a thorough understanding of the magnetic behaviour in the near-Bogomolny critical regime at kappa similar to kappa(c) remains lacking. Here we report that in confined systems the critical regime expands over a finite interval of kappa forming a critical superconducting state. We show that in this state, in a sample with dimensions comparable to the vortex core size, vortices merge into a multi-quanta droplet, which undergoes Rayleigh instability(5) on increasing kappa and decays by emitting single vortices. Superconducting vortices realize Nielsen-Olesen singular solutions of the Abelian Higgs model, which is pervasive in phenomena ranging from quantum electrodynamics to cosmology(6-9). Our study of the transient dynamics of Abrikosov-Nielsen-Olesen vortices in systems with boundaries promises access to non-trivial effects in quantum field theory by means of bench-top laboratory experiments.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000346831100018 Publication Date (down) 2014-11-06
  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 20 Open Access
  Notes ; We would like to thank N. Nekrasov for illuminating discussions. The work was supported by the US Department of Energy, Office of Science Materials Sciences and Engineering Division (V.M.V., W.K.K., U.W., R.X., M.Z., Z.L.X., G.W.C. and partially I.L. through the Materials Theory Institute), by FP7-IRSES-SIMTECH and ITN-NOTEDEV programs (I.L.), and by the Flemish Science Foundation (FWO-Vlaanderen) (M.V.M. and F.M.P.). ; Approved Most recent IF: 22.806; 2015 IF: 20.147
  Call Number c:irua:122791 c:irua:122791 Serial 2815
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