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Author | Vodolazov, D.Y.; Peeters, F.M. | ||||
Title | Temporary cooling of quasiparticles and delay in voltage response of superconducting bridges after abruptly switching on the supercritical current | Type | A1 Journal article | ||
Year | 2014 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 90 | Issue | 9 | Pages | 094504 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | We revisit the problem of the dynamic response of a superconducting bridge after abruptly switching on the supercritical current. In contrast to previous theoretical works we take into account spatial gradients and use both the local temperature approach and the kinetic equation for the distribution function of quasiparticles. We find that the temperature dependence of the finite delay time t(d) in the voltage response is model dependent and relatively large t(d) is connected with temporary cooling of quasiparticles during decay of superconducting order parameter vertical bar Delta vertical bar in time. It turns out that the presence of even small inhomogeneities in the bridge or finite length of the homogenous bridge favors a local suppression of vertical bar Delta vertical bar during the dynamic response. It results in a decrease of the delay time, in comparison with the spatially uniform model, due to the diffusion of nonequilibrium quasiparticles from the region with locally suppressed vertical bar Delta vertical bar. In the case when the current density is maximal near the edge of a not very wide bridge the delay time is mainly connected with the time needed for the nucleation (entrance) of the first vortex and t(d) could be tuned by a weak external magnetic field. We also find that a short alternating current pulse (sinusoidlike) with zero time average may result in a nonzero time- averaged voltage response where its sign depends on the phase of the ac current. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000342103600002 | Publication Date | 2014-09-10 | |
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Series Volume | Series Issue | Edition | |||
ISSN | 1098-0121;1550-235X; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 2 | Open Access | |
Notes | ; This work was partially supported by the Russian Foundation for Basic Research (Project No. 12-02-00509), by the Ministry of Education and Science of the Russian Federation (the agreement of August 27, 2013, No. 02.B.49.21.0003, between The Ministry of Education and Science of the Russian Federation and Lobachevsky State University of Nizhni Novgorod) and by the European Science Foundation (ESF) within the framework of the activity entitled “Exploring the Physics of Small Devices (EPSD)” (Project No. 4327). ; | Approved | Most recent IF: 3.836; 2014 IF: 3.736 | ||
Call Number | UA @ lucian @ c:irua:119908 | Serial | 3504 | ||
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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. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000345642000015 | Publication Date | 2014-11-17 | |
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Series Volume | Series Issue | Edition | |||
ISSN | 1098-0121;1550-235X; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 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 | ||
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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. |
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000345467000003 | Publication Date | 2014-11-20 | |
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Impact Factor | Times cited | 17 | Open Access | ||
Notes | Approved | Most recent IF: NA | |||
Call Number | EMAT @ emat @ | Serial | 4544 | ||
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Author | Hellar-Kihampa, H.; Potgieter-Vermaak, S.; De Wael, K.; Lugwisha, E.; van Espen, P.; Van Grieken, R. | ||||
Title | Concentration profiles of metal contaminants in fluvial sediments of a rural-urban drainage basin in Tanzania | Type | A1 Journal article | ||
Year | 2014 | Publication | International journal of environmental analytical chemistry | Abbreviated Journal | Int J Environ An Ch |
Volume | 94 | Issue | 1 | Pages | 77-98 |
Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
Abstract | This study investigated concentration profiles of trace, rare earth and platinum group metals in fluvial sediments from the Pangani river basin (43,650 km2), one of the largest river basins in Tanzania, to assess its environmental quality. Sediment samples were collected in two distinct seasons from 12 representative sites of diverse land-use practices and characterised by ICP-MS after optimised microwave digestion. Ecological risks were assessed by evaluation of pollution index and comparison with legislated sediment quality guidelines (SQG). The results revealed contamination by some trace metals (e.g. Pb, V, Cu, Cr, Ni, Cd, As, Co, Mn and Zn) in concentrations ranging from 0.7 to 2940 mg kg−1, and four rare earth elements (Y, Ce, Nd, Yb) in concentrations ranging from 0.9 (Yb) to 500 mg kg−1 dry weight (Ce), which significantly exceeded the estimated background values at some stations. Palladium was the only platinum group element that was detected in quantifiable concentrations (0.33.5 mg kg−1). Concentrations of some trace metals exceeded the SQGs at some localised areas. Principal component analysis and multivariate correlations indicated geochemical characteristics of the area as the major control of metal concentrations and spatial variability. Organic matter and clay contents also played a significant role in metal distributions. Assessment of land-use practices upstream of the sampling locations was used to trace potential anthropogenic sources of metal enrichments, where highest levels were found in areas close to urban centres and agricultural activities. The study provides baseline data for future monitoring programs, and highlights the need for more comprehensive analysis involving a wider spatio-temporal scale and ecotoxicological risk assessment. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000329774500007 | Publication Date | 2013-05-24 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0306-7319 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 1.208 | Times cited | 5 | Open Access | |
Notes | ; The participants of this research gratefully acknowledge the financial support of the Belgian Development Agency (BTC). The contribution of the Pangani Basin Water Board (PBWB), especially Ms Arafa Maggidi in provision of valuable information and assistance with the sampling campaigns is greatly appreciated. We sincerely acknowledge the assistance of Mr. Elisa Dunstan Kiwelu of Ardhi University, Dar es Salaam, Tanzania in mapping the study area; Mr Peter Machibya of the Department of Geology, University of Dar es Salaam, Tanzania in sediment characterisation; and Dr Valentine Kayawe Mubiana of the Department of Biology, University of Antwerp in ICP-MS analysis. The contributions of six anonymous reviewers, which greatly improved the manuscript for this paper, are highly appreciated. ; | Approved | Most recent IF: 1.208; 2014 IF: 1.295 | ||
Call Number | UA @ admin @ c:irua:109234 | Serial | 5547 | ||
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Author | Huygh, S.; Bogaerts, A.; van Duin, A.C.T.; Neyts, E.C. | ||||
Title | Development of a ReaxFF reactive force field for intrinsic point defects in titanium dioxide | Type | A1 Journal article | ||
Year | 2014 | Publication | Computational materials science | Abbreviated Journal | Comp Mater Sci |
Volume | 95 | Issue | Pages | 579-591 | |
Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
Abstract | A reactive ReaxFF force field is developed for studying the influence of intrinsic point defects on the chemistry with TiO2 condensed phases. The force field parameters are optimized to ab initio data for the equations of state, relative phase stabilities for titanium and titanium dioxide, potential energy differences for (TiO2)n-clusters (n = 116). Also data for intrinsic point defects in anatase were added. These data contain formation energies for interstitial titanium and oxygen vacancies, diffusion barriers of the oxygen vacancies and molecular oxygen adsorption on a reduced anatase (101) surface. Employing the resulting force field, we study the influence of concentration of oxygen vacancies and expansion or compression of an anatase surface on the diffusion of the oxygen vacancies. Also the barrier for oxygen diffusion in the subsurface region is evaluated using this force field. This diffusion barrier of 27.7 kcal/mol indicates that the lateral redistribution of oxygen vacancies on the surface and in the subsurface will be dominated by their diffusion in the subsurface, since both this barrier as well as the barriers for diffusion from the surface to the subsurface and vice versa (17.07 kcal/mol and 21.91 kcal/mol, respectively, as calculated with DFT), are significantly lower than for diffusion on the surface (61.12 kcal/mol as calculated with DFT). | ||||
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Language | Wos | 000343781700077 | Publication Date | 2014-09-16 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0927-0256; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.292 | Times cited | 15 | Open Access | |
Notes | Approved | Most recent IF: 2.292; 2014 IF: 2.131 | |||
Call Number | UA @ lucian @ c:irua:119409 | Serial | 682 | ||
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Author | Espinoza Torres, C.; Condó, A.M.; Haberkorn, N.; Zelaya, E.; Schryvers, D.; Guimpel, J.; Lovey, F.C. | ||||
Title | Structures in textured Cu-Al-Ni shape memory thin films grown by sputtering | Type | A1 Journal article | ||
Year | 2014 | Publication | Materials characterization | Abbreviated Journal | Mater Charact |
Volume | 96 | Issue | Pages | 256-262 | |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | The structure and texture formation in CuAlNi thin films of different thicknesses (1 μm to 5 μm) grown by DC magnetron sputtering without any intentional heating of the substrate are reported. The as-grown films present grains with an average size of 20 nm. The films with thickness of 1 μm have a single metastable phase with a hexagonal structure and are textured with planes (0002) parallel to the plane of the films. It was observed that thicker films present phase coexistence between metastable hexagonal and body centered cubic structures with a gradual increment of the body centered cubic phase fraction. The films with thickness of 5 μm are textured with planes (0002) and View the MathML source101¯0 in the hexagonal structure, whereas in the body centered cubic structure the films are textured with {110} planes parallel to the plane of the films. This fact can be associated with self-heating of the substrate during the growth of the films and with the relative stability of the metastable phases. Free standing films annealed in a second step (1123 K for 1 h) present austenitic phase with L21 structure and sub-micrometric grains textured with {220}L21 planes parallel to the plane of the films. The martensitic transformation temperature was determined from the analysis of resistance against temperature measurements. | ||||
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Publisher | Place of Publication | New York | Editor | ||
Language | Wos | 000343346400032 | Publication Date | 2014-08-10 | |
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Series Volume | Series Issue | Edition | |||
ISSN | 1044-5803; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.714 | Times cited | 9 | Open Access | |
Notes | (CONICET PIP 11220090100457) and MINCYT-FWO International Exchange Project FW/09/03 is also acknowledged | Approved | Most recent IF: 2.714; 2014 IF: 1.845 | ||
Call Number | UA @ lucian @ c:irua:118931 | Serial | 3321 | ||
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Author | Akbulut, S.; Cevik, U.; Van, A.A.; De Wael, K.; Van Grieken, R. | ||||
Title | Precision and accuracy of ST-EDXRF performance for As determination comparing with ICP-MS and evaluation of As deviation in the soil media | Type | A1 Journal article | ||
Year | 2014 | Publication | Chemosphere | Abbreviated Journal | Chemosphere |
Volume | 96 | Issue | Pages | 16-22 | |
Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
Abstract | The present study was conducted to (i) determine the precision and accuracy of arsenic measurement in soil samples using ST-EDXRF by comparison with the results of ICP-MS analyses and (ii) identify the relationship of As concentration with soil characteristics. For the analysis of samples, inductively coupled plasma mass spectrometry (ICP-MS) and energy dispersive X-ray fluorescence spectrometry (EDXRF) were performed. According to the results found in the soil samples, the addition of HCl to HNO3, used for the digestion gave significant variations in the recovery of As. However, spectral interferences between peaks for As and Pb can affect detection limits and accuracy for XRF analysis. When comparing the XRF and ICP-MS results a correlation was observed with R2 = 0.8414. This means that using a ST-EDXRF spectrometer, it is possible to achieve accurate and precise analysis by the calibration of certified reference materials and choosing an appropriate secondary target. On the other hand, with regard to soil characteristics analyses, the study highlighted that As is mostly anthropogenically enriched in the studied area. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000328182200002 | Publication Date | 2013-08-14 | |
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Series Volume | Series Issue | Edition | |||
ISSN | 0045-6535; 1879-1298 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.208 | Times cited | 5 | Open Access | |
Notes | ; ; | Approved | Most recent IF: 4.208; 2014 IF: 3.340 | ||
Call Number | UA @ admin @ c:irua:109437 | Serial | 5782 | ||
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Author | Odin, G.P.; Vanmeert, F.; Janssens, K.; Lelièvre, H.; Mertz, J.-D.; Rouchon, V. | ||||
Title | Accelerated ageing of shales of palaeontological interest : impact of temperature conditions | Type | A1 Journal article | ||
Year | 2014 | Publication | Annales de paléontologie | Abbreviated Journal | Ann Paleontol |
Volume | 100 | Issue | 2 | Pages | 137-149 |
Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
Abstract | The palaeontological collections of the Muséum national dHistoire naturelle (MNHN, Paris, France) and the Muséum dHistoire naturelle dAutun (MHNA, Autun, France) include many fossil specimens originating from the argillaceous shales of the Autun basin (Saône-et-Loire, France). These fossils are preserved within sedimentary rocks containing unstable sulphide compounds, such as pyrite, which may deteriorate in contact with water and oxygen. This alteration provokes crystalline efflorescence and cracks, thus compromising the preservations of the fossils. This work constitutes the first step of a project that aims to understand the mechanisms of alteration of these materials in order to define conservation guidelines for palaeontological collections. For this purpose, eight damaged specimens originating from the Permian Autun basin (Saône-et-Loire, France) were selected and analyzed by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy coupled to energy dispersive X-ray spectrometry (SEM/EDS) and X-ray absorption spectroscopy at the threshold of the sulphur Kα-edge (XANES). This methodology enabled the characterization of the matrices composition and the chemical nature of the alterations. Subsequently, we have sought to reproduce by artificial ageing the alteration phenomena encountered in the collections. New shale samples were collected on seven outcrops of the same Autun basin. They were analyzed and subjected to artificial ageing at 50% relative humidity (RH) and at temperatures ranging between 40 °C and 90 °C. Our work shows that damaged specimens and newly collected shale have a similar mineralogical composition. Yet the crystalline efflorescence material formed on the surface of damaged specimens belongs to the iron sulphate group whereas gypsum predominates on artificially aged shale samples. Reproducing the alterations observed on specimens by artificial ageing remains therefore problematic. Additionally, it appears that the temperature of ageing controls the nature of the damage: at 40 °C, many samples are mechanically damaged whereas no or minor crystalline efflorescence occurs. At 90 °C, it is the opposite tendency that is observed. Finally, mechanical damages do not seem to be correlated with the development of the efflorescence: samples with efflorescent crystals generally do not show clearly visible cracks; those that seem most fragmented do not show any visible efflorescence. | ||||
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Language | Wos | 000338607500006 | Publication Date | 2014-01-24 | |
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ISSN | 0753-3969 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 1.113 | Times cited | 5 | Open Access | |
Notes | ; This work is part of a PhD that is funded by the Museum national d'Histoire naturelle, Paris, France and was additionally supported via the S2-ART project (SDD programme of BELSPO, Brussels). The research was realized in partnership with the Palaeontological Collection Management Unit, Collection Department and with the Centre de Recherche sur la Paleodiversite et les Paleoenvironnements (CR2P, CNRS, UMR7207) of the Museum national d'Histoire naturelle, Paris, France. We are grateful to our colleagues MM. Jean Dejax and Dominique Chabard who provided palaeontological specimens and gave us access to shale deposits and Mrs Marie-Madeleine Blanc-Valleron who was of great help for the interpretation of the XRD data. ; | Approved | Most recent IF: 1.113; 2014 IF: 0.970 | ||
Call Number | UA @ admin @ c:irua:116594 | Serial | 5456 | ||
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Author | Van de Voorde, L.; Vandevijvere, M.; Vekemans, B.; Van Pevenage, J.; Caen, J.; Vandenabeele, P.; van Espen, P.; Vincze, L. | ||||
Title | Study of a unique 16th century Antwerp majolica floor in the Rameyenhof castle's chapel by means of X-ray fluorescence and portable Raman analytical instrumentation | Type | A1 Journal article | ||
Year | 2014 | Publication | Spectrochimica acta: part B : atomic spectroscopy | Abbreviated Journal | |
Volume | 102 | Issue | Pages | 28-35 | |
Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp Cultural Heritage Sciences (ARCHES) | ||||
Abstract | The most unique and only known 16th century Antwerp majolica tile floor in Belgium is situated in a tower of the Rameyenhof castle (Gestel, Belgium). This exceptional work of art has recently been investigated in situ by using X-ray fluorescence (XRF) and Raman spectroscopy in order to study the material characteristics. This study reports on the result of the analyses based on the novel combination of non-destructive and portable instrumentation, including a handheld XRF spectrometer for obtaining elemental information and a mobile Raman spectrometer for retrieving structural and molecular information on the floor tiles in the Rameyenhof castle and on a second, similar medallion, which is stored in the Rubens House museum in Antwerp (Belgium). The investigated material, majolica, is a type of ceramic, which fascinated many people and potters throughout history by its beauty and colourful appearance. In this study the characteristic major/minor and trace element signature of 16th century Antwerp majolica is determined and the pigments used for the colourful paintings present on the floor are identified. Furthermore, based on the elemental fingerprint of the white glaze, and in particular on the presence of zinc in the tiles – an element that was not used for making 16th century majolica – valuable information about the originality of the chapel floor and the two central medallions is acquired. (C) 2014 Elsevier B.V. All rights reserved. | ||||
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Language | Wos | 000347604100005 | Publication Date | 2014-10-25 | |
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ISSN | 0584-8547; 1873-3565 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | Times cited | Open Access | |||
Notes | Approved | no | |||
Call Number | UA @ admin @ c:irua:123850 | Serial | 8592 | ||
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Author | Neek-Amal, M.; Peeters, F.M. | ||||
Title | Graphene on boron-nitride : Moiré pattern in the van der Waals energy | Type | A1 Journal article | ||
Year | 2014 | Publication | Applied physics letters | Abbreviated Journal | Appl Phys Lett |
Volume | 104 | Issue | 4 | Pages | 041909-4 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | The spatial dependence of the van der Waals (vdW) energy between graphene and hexagonal boron-nitride (h-BN) is investigated using atomistic simulations. The van der Waals energy between graphene and h-BN shows a hexagonal superlattice structure identical to the observed Moire pattern in the local density of states, which depends on the lattice mismatch and misorientation angle between graphene and h-BN. Our results provide atomistic features of the weak van der Waals interaction between graphene and BN which are in agreement with experiment and provide an analytical expression for the size of the spatial variation of the weak van der Waals interaction. We also found that the A-B-lattice symmetry of graphene is broken along the armchair direction. (C) 2014 AIP Publishing LLC. | ||||
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Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
Language | Wos | 000331209900028 | Publication Date | 2014-01-31 | |
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ISSN | 0003-6951;1077-3118; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.411 | Times cited | 61 | Open Access | |
Notes | ; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem Foundation of the Flemish Government. M.N.-A was supported by the EU-Marie Curie IIF postdoctoral Fellowship/299855. ; | Approved | Most recent IF: 3.411; 2014 IF: 3.302 | ||
Call Number | UA @ lucian @ c:irua:115802 | Serial | 1374 | ||
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Author | Neek-Amal, M.; Peeters, F.M. | ||||
Title | Graphene on hexagonal lattice substrate : stress and pseudo-magnetic field | Type | A1 Journal article | ||
Year | 2014 | Publication | Applied physics letters | Abbreviated Journal | Appl Phys Lett |
Volume | 104 | Issue | 17 | Pages | 173106 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Moire patterns in the pseudo-magnetic field and in the strain profile of graphene (GE) when put on top of a hexagonal lattice substrate are predicted from elasticity theory. The van der Waals interaction between GE and the substrate induces out-of-plane deformations in graphene which results in a strain field, and consequently in a pseudo-magnetic field. When the misorientation angle is about 0.5 degrees, a three-fold symmetric strain field is realized that results in a pseudo-magnetic field very similar to the one proposed by F. Guinea, M. I. Katsnelson, and A. K. Geim [Nature Phys. 6, 30 (2010)]. Our results show that the periodicity and length of the pseudo-magnetic field can be tuned in GE by changing the misorientation angle and substrate adhesion parameters and a considerable energy gap (23 meV) can be obtained due to out-of-plane deformation of graphene which is in the range of recent experimental measurements (20-30 meV). (C) 2014 AIP Publishing LLC. | ||||
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Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
Language | Wos | 000336142500066 | Publication Date | 2014-05-02 | |
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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 | 14 | Open Access | |
Notes | ; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem Foundation of the Flemish Government. M.N.-A. was supported by the EU-Marie Curie IIF postdoc Fellowship 299855. ; | Approved | Most recent IF: 3.411; 2014 IF: 3.302 | ||
Call Number | UA @ lucian @ c:irua:117724 | Serial | 1375 | ||
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Author | Clima, S.; Wouters, D.J.; Adelmann, C.; Schenk, T.; Schroeder, U.; Jurczak, M.; Pourtois, G. | ||||
Title | Identification of the ferroelectric switching process and dopant-dependent switching properties in orthorhombic HfO2 : a first principles insight | Type | A1 Journal article | ||
Year | 2014 | Publication | Applied physics letters | Abbreviated Journal | Appl Phys Lett |
Volume | 104 | Issue | 9 | Pages | 092906 |
Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
Abstract | The origin of the ferroelectric polarization switching in orthorhombic HfO2 has been investigated by first principles calculations. The phenomenon can be regarded as being the coordinated displacement of four O ions in the orthorhombic unit cell, which can lead to a saturated polarization as high as 53 mu C/cm(2). We show the correlation between the computed polarization reversal barrier and the experimental coercive fields. (C) 2014 AIP Publishing LLC. | ||||
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Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
Language | Wos | 000332729200078 | Publication Date | 2014-03-06 | |
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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 | 79 | Open Access | |
Notes | Approved | Most recent IF: 3.411; 2014 IF: 3.302 | |||
Call Number | UA @ lucian @ c:irua:116873 | Serial | 1550 | ||
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Author | Čukarić, N.A.; Tadić, M.Z.; Partoens, B.; Peeters, F.M. | ||||
Title | The interband optical absorption in silicon quantum wells : application of the 30-band k . p model | Type | A1 Journal article | ||
Year | 2014 | Publication | Applied physics letters | Abbreviated Journal | Appl Phys Lett |
Volume | 104 | Issue | 24 | Pages | 242103 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | The interband optical absorption in Si/SiO2 quantum wells is calculated as function of the well width (W) and the evolution from an indirect to a direct gap material as function of the well width is investigated. In order to compute the electron states in the conduction band, the 30-band k . p model is employed, whereas the 6-band Luttinger-Kohn model is used for the hole states. We found that the effective direct band gap in the quantum well agrees very well with the W-2 scaling result of the single-band model. The interband matrix elements for linear polarized light oscillate with the quantum well width, which agrees qualitatively with a single band calculation. Our theoretical results indicate that the absorption can be maximized by a proper choice of the well width. However, the obtained absorption coefficients are at least an order of magnitude smaller than for a typical direct semiconductor even for a well width of 2 nm. (C) 2014 AIP Publishing LLC. | ||||
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Corporate Author | Thesis | ||||
Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
Language | Wos | 000337915000033 | Publication Date | 2014-06-18 | |
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 | 1 | Open Access | |
Notes | ; This work was supported by the Ministry of Education, Science, and Technological Development of Serbia, the Flemish fund for Scientific Research (FWO-Vl), and the Methusalem programme of the Flemish government. ; | Approved | Most recent IF: 3.411; 2014 IF: 3.302 | ||
Call Number | UA @ lucian @ c:irua:118448 | Serial | 1689 | ||
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Author | Çakir, D.; Peeters, F.M.; Sevik, C. | ||||
Title | Mechanical and thermal properties of h-MX2 (M = Cr, Mo, W; X = O, S, Se, Te) monolayers : a comparative study | Type | A1 Journal article | ||
Year | 2014 | Publication | Applied physics letters | Abbreviated Journal | Appl Phys Lett |
Volume | 104 | Issue | 20 | Pages | 203110 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Using density functional theory, we obtain the mechanical and thermal properties of MX2 monolayers (where M = Cr, Mo, W and X = O, S, Se, Te). The C-centered phonon frequencies (i.e., A(1), A(2)'', E ', and E ''), relative frequency values of A(1), and E ' modes, and mechanical properties (i.e., elastic constants, Young modulus, and Poisson's ratio) display a strong dependence on the type of metal and chalcogenide atoms. In each chalcogenide (metal) group, transition-metal dichalcogenides (TMDCs) with W (O) atom are found to be much stiffer. Consistent with their stability, the thermal expansion of lattice constants for TMDCs with O (Te) is much slower (faster). Furthermore, in a heterostructure of these materials, the difference of the thermal expansion of lattice constants between the individual components becomes quite tiny over the whole temperature range. The calculated mechanical and thermal properties show that TMDCs are promising materials for heterostructures. (C) 2014 AIP Publishing LLC. | ||||
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Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
Language | Wos | 000337140800063 | Publication Date | 2014-05-24 | |
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 | 130 | Open Access | |
Notes | ; Cem Sevik acknowledges the support from Scientific and Technological Research Council of Turkey (TUBITAK-113F096) and Anadolu University (BAP-1306F261 and -1306F281) to this project. We would also like to thank the ULAKBIM High Performance and Grid Computing Center for a generous time allocation for our projects. D. C. was supported by a FWO Pegasus-short Marie Curie Fellowship. Part of this work was supported by the Methusalem foundation of the Flemish Government. ; | Approved | Most recent IF: 3.411; 2014 IF: 3.302 | ||
Call Number | UA @ lucian @ c:irua:118379 | Serial | 1974 | ||
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Author | Idrissi, H.; Kobler, A.; Amin-Ahmadi, B.; Coulombier, M.; Galceran, M.; Raskin, J.-P.; Godet, S.; Kuebel, C.; Pardoen, T.; Schryvers, D. | ||||
Title | Plasticity mechanisms in ultrafine grained freestanding aluminum thin films revealed by in-situ transmission electron microscopy nanomechanical testing | Type | A1 Journal article | ||
Year | 2014 | Publication | Applied physics letters | Abbreviated Journal | Appl Phys Lett |
Volume | 104 | Issue | 10 | Pages | 101903 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | In-situ bright field transmission electron microscopy (TEM) nanomechanical tensile testing and in-situ automated crystallographic orientation mapping in TEM were combined to unravel the elementary mechanisms controlling the plasticity of ultrafine grained Aluminum freestanding thin films. The characterizations demonstrate that deformation proceeds with a transition from grain rotation to intragranular dislocation glide and starvation plasticity mechanism at about 1% deformation. The grain rotation is not affected by the character of the grain boundaries. No grain growth or twinning is detected. (C) 2014 AIP Publishing LLC. | ||||
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Corporate Author | Thesis | ||||
Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
Language | Wos | 000333082800022 | Publication Date | 2014-03-12 | |
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 | 24 | Open Access | |
Notes | Approved | Most recent IF: 3.411; 2014 IF: 3.302 | |||
Call Number | UA @ lucian @ c:irua:116866 | Serial | 2649 | ||
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Author | Shakouri, K.; Vasilopoulos, P.; Vargiamidis, V.; Hai, G.-Q.; Peeters, F.M. | ||||
Title | Spin- and valley-dependent commensurability oscillations and electric-field-induced quantum Hall plateaux in periodically modulated silicene | Type | A1 Journal article | ||
Year | 2014 | Publication | Applied physics letters | Abbreviated Journal | Appl Phys Lett |
Volume | 104 | Issue | 21 | Pages | 213109 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | We study the commensurability oscillations in silicene subject to a perpendicular electric field E-z, a weak magnetic field B, and a weak periodic potential V = V-0 cos(Cy); C = 2 pi/a(0) with a(0) its period. The field E-z and/or the modulation lift the spin degeneracy of the Landau levels and lead to spin and valley resolved Weiss oscillations. The spin resolution is maximal when the field E-z is replaced by a periodic one E-z = E-0 cos(Dy); D = 2 pi/b(0), while the valley one is maximal for b(0) = a(0). In certain ranges of B values, the current is fully spin or valley polarized. Additional quantum Hall conductivity plateaux arise due to spin and valley intra-Landau-level transitions. (C) 2014 AIP Publishing LLC. | ||||
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Corporate Author | Thesis | ||||
Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
Language | Wos | 000337143000047 | Publication Date | 2014-05-30 | |
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 | 16 | Open Access | |
Notes | ; The work was supported by the Flemish Science Foundation (FWO-VI), the Methusalem Foundation of the Flemish Government, and by the Canadian NSERC Grant No. OGP0121756. Also, G. Q. H. was supported by FAPESP and CNPq (Brazil). ; | Approved | Most recent IF: 3.411; 2014 IF: 3.302 | ||
Call Number | UA @ lucian @ c:irua:118409 | Serial | 3078 | ||
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Author | M. K. Kinyanjui, N. Gauquelin, E. Benckiser, H. –U. Habermeier, B. Keimer, U. Kaiser and G.A. Botton | ||||
Title | Local lattice distortion and anisotropic modulation in Epitaxially Strained LaNiO3/LaAlO3 hetero-structures | Type | A1 Journal Article | ||
Year | 2014 | Publication | Applied Physics Letters | Abbreviated Journal | |
Volume | 104 | Issue | Pages | 221909 | |
Keywords | A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; | ||||
Abstract | Using a complementary combination of x-ray diffraction and atomically resolved imaging we investigated the lattice structure of epitaxial LaNiO3/LaAlO3 superlattices grown on a compressive-strain inducing LaSrAlO4 (001) substrate. A refinement of the structure obtained from the x-ray data revealed the monoclinic I 2/c 1 1 space group. The (Ni/Al)O6 octahedral rotation angle perpendicular to the superlattice plane is enhanced, and the one parallel to the plane is reduced with respect to the corresponding bulk values. High-angle annular dark field imaging was used to determine the lattice parameters within the superlattice unit cell. High-resolution electron microscopy images of the oxygen atoms are consistent with the x-ray results. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000337161700029 | Publication Date | 2014-06-07 | |
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Impact Factor | Times cited | 22 | Open Access | ||
Notes | Approved | Most recent IF: NA | |||
Call Number | EMAT @ emat @ | Serial | 4545 | ||
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Author | Jungbauer, M.; Huehn, S.; Egoavil, R.; Tan, H.; Verbeeck, J.; Van Tendeloo, G.; Moshnyaga, V. | ||||
Title | Atomic layer epitaxy of Ruddlesden-Popper SrO(SrTiO3)n films by means of metalorganic aerosol deposition | Type | A1 Journal article | ||
Year | 2014 | Publication | Applied physics letters | Abbreviated Journal | Appl Phys Lett |
Volume | 105 | Issue | 25 | Pages | 251603 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | We report an atomic layer epitaxial growth of Ruddlesden-Popper (RP) thin films of SrO(SrTiO3)(n) (n = infinity, 2, 3, 4) by means of metalorganic aerosol deposition (MAD). The films are grown on SrTiO3(001) substrates by means of a sequential deposition of Sr-O/Ti-O-2 atomic monolayers, monitored in-situ by optical ellipsometry. X-ray diffraction and transmission electron microscopy (TEM) reveal the RP structure with n = 2-4 in accordance with the growth recipe. RP defects, observed by TEM in a good correlation with the in-situ ellipsometry, mainly result from the excess of SrO. Being maximal at the film/substrate interface, the SrO excess rapidly decreases and saturates after 5-6 repetitions of the SrO(SrTiO3)(4) block at the level of 2.4%. This identifies the SrTiO3 substrate surface as a source of RP defects under oxidizing conditions within MAD. Advantages and limitations of MAD as a solution-based and vacuum-free chemical deposition route were discussed in comparison with molecular beam epitaxy. (C) 2014 AIP Publishing LLC. | ||||
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Corporate Author | Thesis | ||||
Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
Language | Wos | 000346914000007 | Publication Date | 2014-12-26 | |
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 | 32 | Open Access | |
Notes | 246102 IFOX; 278510 VORTEX; 246791 COUNTATOMS; Hercules; 312483 ESTEEM2; esteem2jra3 ECASJO; | Approved | Most recent IF: 3.411; 2014 IF: 3.302 | ||
Call Number | UA @ lucian @ c:irua:122830UA @ admin @ c:irua:122830 | Serial | 172 | ||
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Author | Samal, D.; Tan, H.; Takamura, Y.; Siemons, W.; Verbeeck, J.; Van Tendeloo, G.; Arenholz, E.; Jenkins, C.A.; Rijnders, G.; Koster, G. | ||||
Title | Direct structural and spectroscopic investigation of ultrathin films of tetragonal CuO: Six-fold coordinated copper | Type | A1 Journal article | ||
Year | 2014 | Publication | Europhysics letters | Abbreviated Journal | Epl-Europhys Lett |
Volume | 105 | Issue | 1 | Pages | 17003-17005 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Unlike other 3d transition metal monoxides (MnO, FeO, CoO, and NiO), CuO is found in a low-symmetry distorted monoclinic structure rather than the rocksalt structure. We report here of the growth of ultrathin CuO films on SrTiO3 substrates; scanning transmission electron microscopy was used to show the stabilization of a tetragonal rocksalt structure with an elongated c-axis such that c/a similar to 1.34 and the Cu-O-Cu bond angle similar to 180 degrees, pointing to metastable six-fold coordinated Cu. X-ray absorption spectroscopy demonstrates that the hole at the Cu site for the CuO is localized in 3d(x2-y2) orbital unlike the well-studied monoclinic CuO phase. The experimental confirmation of the tetragonal structure of CuO opens up new avenues to explore electronic and magnetic properties of six-fold coordinated Cu. Copyright (C) EPLA, 2014 | ||||
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Publisher | Place of Publication | Paris | Editor | ||
Language | Wos | 000331197100015 | Publication Date | 2014-01-30 | |
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ISSN | 0295-5075;1286-4854; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 1.957 | Times cited | 15 | Open Access | |
Notes | This work was carried out with financial support from the AFOSR and EOARD projects (project No.: FA8655-10-1-3077) and also supported by funding from the European Research Council under the 7th Framework Program (FP7), ERC grant No. 246791 – COUNTATOMS, ERC Starting Grant 278510 VORTEX, Grant No. NMP3-LA-2010-246102 IFOX and an Integrated Infrastructure Initiative, reference No. 312483-ESTEEM2. The Qu-Ant-EM microscope was partly funded by the Hercules fund from the Flemish Government. Advanced Light Source is supported by the Office of Science, Office of Basic Energy Sciences of the U.S. Department of Energy (DOE) under Contract No. DE-AC02-05CH11231. YT acknowledges support from the National Science Foundation (DMR-0747896). WS was supported by the US DOE, Basic Energy Sciences, Materials Sciences and Engineering Division. ECASJO_; | Approved | Most recent IF: 1.957; 2014 IF: 2.095 | ||
Call Number | UA @ lucian @ c:irua:115806UA @ admin @ c:irua:115806 | Serial | 722 | ||
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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. | ||||
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Corporate Author | Thesis | ||||
Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
Language | Wos | 000346266000066 | Publication Date | 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 | Verreck, D.; Verhulst, A.S.; Sorée, B.; Collaert, N.; Mocuta, A.; Thean, A.; Groeseneken, G. | ||||
Title | Improved source design for p-type tunnel field-effect transistors : towards truly complementary logic | Type | A1 Journal article | ||
Year | 2014 | Publication | Applied physics letters | Abbreviated Journal | Appl Phys Lett |
Volume | 105 | Issue | 24 | Pages | 243506 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Complementary logic based on tunnel field-effect transistors (TFETs) would drastically reduce power consumption thanks to the TFET's potential to obtain a sub-60 mV/dec subthreshold swing (SS). However, p-type TFETs typically do not meet the performance of n-TFETs for direct bandgap III-V configurations. The p-TFET SS stays well above 60 mV/dec, due to the low density of states in the conduction band. We therefore propose a source configuration in which a highly doped region is maintained only near the tunnel junction. In the remaining part of the source, the hot carriers in the exponential tail of the Fermi-Dirac distribution are blocked by reducing the doping degeneracy, either with a source section with a lower doping concentration or with a heterostructure. We apply this concept to n-p-i-p configurations consisting of In0.53Ga0.47As and an InP-InAs heterostructure. 15-band quantum mechanical simulations predict that the configurations with our source design can obtain sub-60 mV/dec SS, with an on-current comparable to the conventional source design. (C) 2014 AIP Publishing LLC. | ||||
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Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
Language | Wos | 000346643600076 | Publication Date | 2014-12-17 | |
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 | 10 | Open Access | |
Notes | ; D. Verreck acknowledges the support of a Ph.D. stipend from the Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT-Vlaanderen). This work was supported by imec's Industrial Affiliation Program. ; | Approved | Most recent IF: 3.411; 2014 IF: 3.302 | ||
Call Number | UA @ lucian @ c:irua:122798 | Serial | 1568 | ||
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Author | Milovanović, S.P.; Masir, M.R.; Peeters, F.M. | ||||
Title | Interplay between snake and quantum edge states in a graphene Hall bar with a pn-junction | Type | A1 Journal article | ||
Year | 2014 | Publication | Applied physics letters | Abbreviated Journal | Appl Phys Lett |
Volume | 105 | Issue | 12 | Pages | 123507 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | The magneto- and Hall resistance of a locally gated cross shaped graphene Hall bar is calculated. The edge of the top gate is placed diagonally across the center of the Hall cross. Four-probe resistance is calculated using the Landauer-Büttiker formalism, while the transmission coefficients are obtained using the non-equilibrium Green's function approach. The interplay between transport due to edge channels and snake states is investigated. When two edge channels are occupied, we predict oscillations in the Hall and the bend resistance as function of the magnetic field, which are a consequence of quantum interference between the occupied snake states. | ||||
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Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
Language | Wos | 000343004400090 | Publication Date | 2014-09-27 | |
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 | 18 | Open Access | |
Notes | This work was supported by the Flemish Science Foundation (FWO-Vl), the European Science Foundation (ESF) under the EUROCORES Program EuroGRAPHENE within the project CONGRAN and the Methusalem Foundation of the Flemish government. | Approved | Most recent IF: 3.411; 2014 IF: 3.302 | ||
Call Number | UA @ lucian @ c:irua:121119 | Serial | 1704 | ||
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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. | ||||
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Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
Language | Wos | 000345000000086 | Publication Date | 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 | Gonnissen, J.; de Backer, A.; den Dekker, A.J.; Martinez, G.T.; Rosenauer, A.; Sijbers, J.; Van Aert, S. | ||||
Title | Optimal experimental design for the detection of light atoms from high-resolution scanning transmission electron microscopy images | Type | A1 Journal article | ||
Year | 2014 | Publication | Applied physics letters | Abbreviated Journal | Appl Phys Lett |
Volume | 105 | Issue | 6 | Pages | 063116 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab | ||||
Abstract | We report an innovative method to explore the optimal experimental settings to detect light atoms from scanning transmission electron microscopy (STEM) images. Since light elements play a key role in many technologically important materials, such as lithium-battery devices or hydrogen storage applications, much effort has been made to optimize the STEM technique in order to detect light elements. Therefore, classical performance criteria, such as contrast or signal-to-noise ratio, are often discussed hereby aiming at improvements of the direct visual interpretability. However, when images are interpreted quantitatively, one needs an alternative criterion, which we derive based on statistical detection theory. Using realistic simulations of technologically important materials, we demonstrate the benefits of the proposed method and compare the results with existing approaches. | ||||
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Corporate Author | Thesis | ||||
Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
Language | Wos | 000341188700073 | Publication Date | 2014-08-14 | |
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 | 12 | Open Access | |
Notes | FWO (G.0393.11; G.0064.10; and G.0374.13); European Union Seventh Framework Programme [FP7/2007-2013] under Grant Agreement No. 312483 (ESTEEM2); esteem2_jra2 | Approved | Most recent IF: 3.411; 2014 IF: 3.302 | ||
Call Number | UA @ lucian @ c:irua:118333 | Serial | 2482 | ||
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Author | Verhulst, A.S.; Verreck, D.; Pourghaderi, M.A.; Van de Put, M.; Sorée, B.; Groeseneken, G.; Collaert, N.; Thean, A.V.-Y. | ||||
Title | Can p-channel tunnel field-effect transistors perform as good as n-channel? | Type | A1 Journal article | ||
Year | 2014 | Publication | Applied physics letters | Abbreviated Journal | Appl Phys Lett |
Volume | 105 | Issue | 4 | Pages | 043103 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | We show that bulk semiconductor materials do not allow perfectly complementary p- and n-channel tunnel field-effect transistors (TFETs), due to the presence of a heavy-hole band. When tunneling in p-TFETs is oriented towards the gate-dielectric, field-induced quantum confinement results in a highest-energy subband which is heavy-hole like. In direct-bandgap IIIV materials, the most promising TFET materials, phonon-assisted tunneling to this subband degrades the subthreshold swing and leads to at least 10x smaller on-current than the desired ballistic on-current. This is demonstrated with quantum-mechanical predictions for p-TFETs with tunneling orthogonal to the gate, made out of InP, In0.53Ga0.47As, InAs, and a modified version of In0.53Ga0.47As with an artificially increased conduction-band density-of-states. We further show that even if the phonon-assisted current would be negligible, the build-up of a heavy-hole-based inversion layer prevents efficient ballistic tunneling, especially at low supply voltages. For p-TFET, a strongly confined n-i-p or n-p-i-p configuration is therefore recommended, as well as a tensily strained line-tunneling configuration. (C) 2014 AIP Publishing LLC. | ||||
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Corporate Author | Thesis | ||||
Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
Language | Wos | 000341152600067 | Publication Date | 2014-07-30 | |
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 | 8 | Open Access | |
Notes | ; This work was supported by imec's industrial application program. D. Verreck acknowledges the support of a Ph.D. stipend from the Institute for Promotion of Innovation through Science and Technology in Flanders (IWT). ; | Approved | Most recent IF: 3.411; 2014 IF: 3.302 | ||
Call Number | UA @ lucian @ c:irua:134433 | Serial | 4587 | ||
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Author | da Silva, A.L.C.; Candido, L.; Teixeira Rabelo, J.N.; Hai, G.-Q.; Peeters, F.M. | ||||
Title | Anharmonic effects on thermodynamic properties of a graphene monolayer | Type | A1 Journal article | ||
Year | 2014 | Publication | Europhysics letters | Abbreviated Journal | Epl-Europhys Lett |
Volume | 107 | Issue | 5 | Pages | 56004 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | We extend the unsymmetrized self-consistent-field method (USF) for anharmonic crystals to layered non-Bravais crystals to investigate structural, dynamical and thermodynamic properties of a free-standing graphene monolayer. In this theory, the main anharmonicity of the crystal lattice has been included and the quantum corrections are taken into account in an h-expansion for the one-particle density matrix. The obtained result for the thermal expansion coefficient (TEC) of graphene shows a strong temperature dependence and agrees with experimental results by Bao et al. (Nat. Nanotechnol., 4 (2009) 562). The obtained value of TEC at room temperature (300 K) is -6.4 x 10(- 6) K- 1 and it becomes positive for T > T-alpha = 358K. We find that quantum effects are significant for T < 1000 K. The interatomic distance, effective amplitudes of the graphene lattice vibrations, adiabatic and isothermal bulk moduli, isobaric and isochoric heat capacities are also calculated and their temperature dependences are determined. Copyright (C) EPLA, 2014 | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Paris | Editor | ||
Language | Wos | 000341559900020 | Publication Date | 2014-09-05 | |
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 | 23 | Open Access | |
Notes | ; This research was supported by the Brazilian agencies CNPq, FAPEG and FAPESP, the Flemish Science Foundation (FWO-Vl) and the Methusalem Foundation of the Flemish Government. ; | Approved | Most recent IF: 1.957; 2014 IF: 2.095 | ||
Call Number | UA @ lucian @ c:irua:119289 | Serial | 118 | ||
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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 | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Paris | Editor | ||
Language | Wos | 000346792400027 | Publication Date | 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 | ||
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Author | Grujić, M.M.; Tadić, M.Z.; Peeters, F.M. | ||||
Title | Spin-valley filtering in strained graphene structures with artificially induced carrier mass and spin-orbit coupling | Type | A1 Journal article | ||
Year | 2014 | Publication | Physical review letters | Abbreviated Journal | Phys Rev Lett |
Volume | 113 | Issue | 4 | Pages | 046601 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | The interplay of massive electrons with spin-orbit coupling in bulk graphene results in a spin-valley dependent gap. Thus, a barrier with such properties can act as a filter, transmitting only opposite spins from opposite valleys. In this Letter we show that a strain induced pseudomagnetic field in such a barrier will enforce opposite cyclotron trajectories for the filtered valleys, leading to their spatial separation. Since spin is coupled to the valley in the filtered states, this also leads to spin separation, demonstrating a spin-valley filtering effect. The filtering behavior is found to be controllable by electrical gating as well as by strain. | ||||
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Publisher | Place of Publication | New York, N.Y. | Editor | ||
Language | Wos | 000339620300013 | Publication Date | 2014-07-23 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0031-9007;1079-7114; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 8.462 | Times cited | 90 | Open Access | |
Notes | ; This work was supported by the Serbian Ministry of Education, Science, and Technological Development, the Flemish Science Foundation (FWO-V1), and the Methusalem program of the Flemish government. ; | Approved | Most recent IF: 8.462; 2014 IF: 7.512 | ||
Call Number | UA @ lucian @ c:irua:118731 | Serial | 3104 | ||
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Author | Hoffman, B.M.; Lukoyanov, D.; Yang, Z.-Y.; Dean, D.R.; Seefeldt, L.C. | ||||
Title | Mechanism of Nitrogen Fixation by Nitrogenase: The Next Stage | Type | A1 Journal Article | ||
Year | 2014 | Publication | Chemical Reviews | Abbreviated Journal | Chem. Rev. |
Volume | 114 | Issue | 8 | Pages | 4041-4062 |
Keywords | A1 Journal Article; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ; | ||||
Abstract | Ammonia is a crucial nutrient used for plant growth and as a building block in pharmaceutical and chemical industry, produced via nitrogen fixation of the ubiquitous atmospheric N2. Current industrial ammonia production relies heavily on fossil resources, but a lot of work is put into developing non-fossil based pathways. Among these is the use of nonequilibrium plasma. In this work, we investigated water vapor as H source for nitrogen fixation into NH3 by non-equilibrium plasma. The highest selectivity towards NH3 was observed with low amounts of added H2O vapor, but the highest production rate was reached at high H2O vapor. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | Publication Date | 2014-04-23 | ||
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0009-2665 | ISBN | Additional Links | ||
Impact Factor | Times cited | Open Access | |||
Notes | We would like to thank Sylvia Dewilde (Department of Biomedical Sciences) for providing analytical equipment. | Approved | no | ||
Call Number | PLASMANT @ plasmant @ | Serial | 6337 | ||
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Author | Zhang, Y.; Jiang, W.; Zhang, Q.Z.; Bogaerts, A. | ||||
Title | Computational study of plasma sustainability in radio frequency micro-discharges | Type | A1 Journal article | ||
Year | 2014 | Publication | Journal of applied physics | Abbreviated Journal | J Appl Phys |
Volume | 115 | Issue | 19 | Pages | 193301-193311 |
Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
Abstract | We apply an implicit particle-in-cell Monte-Carlo (PIC-MC) method to study a radio-frequency argon microdischarge at steady state in the glow discharge limit, in which the microdischarge is sustained by secondary electron emission from the electrodes. The plasma density, electron energy distribution function (EEDF), and electron temperature are calculated in a wide range of operating conditions, including driving voltage, microdischarge gap, and pressure. Also, the effect of gap size scaling (in the range of 50-1000 μm) on the plasma sustaining voltage and peak electron density at atmospheric pressure is examined, which has not been explored before. In our simulations, three different EEDFs, i.e., a so-called three temperature hybrid mode, a two temperature α mode, and a two temperature γ mode distribution, are identified at different gaps and voltages. The maximum sustaining voltage to avoid a transition from the glow mode to an arc is predicted, as well as the minimum sustaining voltage for a steady glow discharge. Our calculations elucidate that secondary electrons play an essential role in sustaining the discharge, and as a result the relationship between breakdown voltage and gap spacing is far away from the Paschen law at atmospheric pressure. | ||||
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Corporate Author | Thesis | ||||
Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
Language | Wos | 000336920200010 | Publication Date | 2014-05-16 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0021-8979;1089-7550; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.068 | Times cited | 11 | Open Access | |
Notes | Approved | Most recent IF: 2.068; 2014 IF: 2.183 | |||
Call Number | UA @ lucian @ c:irua:116948 | Serial | 458 | ||
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