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Author Silhanek, A.V.; Milošević, M.V.; Kramer, R.B.G.; Berdiyorov, G.R.; Vondel van de, J.; Luccas, R.F.; Puig, T.; Peeters, F.M.; Moshchalkov, V.V.
Title Formation of stripelike flux patterns obtained by freezing kinematic vortices in a superconducting Pb film Type A1 Journal article
Year 2010 Publication Physical review letters Abbreviated Journal Phys Rev Lett
Volume 104 Issue (up) 1 Pages
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We demonstrate experimentally and theoretically that the dissipative state of superconducting samples with a periodic array of holes at high current densities consists of flux rivers resulting from a short-range attractive interaction between vortices. This dynamically induced vortex-vortex attraction results from the migration of quasiparticles out of the vortex core (kinematic vortices). We have directly visualized the formation of vortex chains by scanning Hall probe microscopy after freezing the dynamic state by a field cooling procedure at a constant bias current. Similar experiments carried out in a sample without holes show no hint of flux river formation. We shed light on this nonequilibrium phenomena modeled by time-dependent Ginzburg-Landau simulations.
Address
Corporate Author Thesis
Publisher Place of Publication New York, N.Y. Editor
Language Wos 000273881900033 Publication Date 2010-01-07
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 60 Open Access
Notes ; This work was supported by Methusalem funding by the Flemish government, the Flemish Science Foundation (FWO-VI), the Belgian Science Policy, and the ESF NES network. A. V. S., G. R. B., and J. V. d. V. acknowledge support from FWO-VI R. F. L. acknowledges support from I3P CSIC program and MAT2008-01022. ; Approved Most recent IF: 8.462; 2010 IF: 7.622
Call Number UA @ lucian @ c:irua:81009 Serial 1265
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Author Müller, K.; Schowalter, M.; Rosenauer, A.; Jansen, J.; Tsuda, K.; Titantah, J.T.; Lamoen, D.
Title Refinement of chemically sensitive structure factors using parallel and convergent beam electron nanodiffraction Type A1 Journal article
Year 2010 Publication Journal of physics : conference series Abbreviated Journal
Volume 209 Issue (up) 1 Pages 012025-012025,4
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract We introduce a new method to measure structure factors from parallel beam electron diffraction (PBED) patterns. Bloch wave refinement routines were developed which can minimise the difference between simulated and experimental Bragg intensities via variation of structure factors, Debye parameters, specimen thickness and -orientation. Due to plane wave illumination, the PBED refinement is highly efficient not only in computational respect, but also concerning the experimental effort since energy filtering is shown to have no significant effect on the refinement results. The PBED method was applied to simulated GaAs diffraction patterns to derive systematic errors and rules for the identification of plausible refinement results. The evaluation of experimental GaAs PBED patterns yields a 200 X-ray structure factor of -6.33±0.14. Additionally, we obtained -6.35±0.13 from two-dimensional convergent beam electron diffraction refinements. Both results confirm density functional theory calculations published by Rosenauer et al. and indicate the inaccuracy of isolated atom scattering data, which is crucial e.g. for the composition evaluation by lattice fringe analysis.
Address
Corporate Author Thesis
Publisher Place of Publication Bristol Editor
Language Wos Publication Date 2010-02-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1742-6596; ISBN Additional Links UA library record
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:85761 Serial 2855
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Author Philippaerts, A.; Paulussen, S.; Turner, S.; Lebedev, O.I.; Van Tendeloo, G.; Poelman, H.; Bulut, M.; de Clippel, F.; Smeets, P.; Sels, B.; Jacobs, P.
Title Selectivity in sorption and hydrogenation of methyl oleate and elaidate on MFI zeolites Type A1 Journal article
Year 2010 Publication Journal of catalysis Abbreviated Journal J Catal
Volume 270 Issue (up) 1 Pages 172-184
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Different zeolites were tested for selective removal of methyl elaidate (trans isomer) from an equimolar mixture with methyl oleate (cis isomer). Sorption experiments of the geometric isomers show that only ZSM-5 samples with reduced Al content in the framework are able to discriminate among the bent cis and the linear trans fatty acid methyl esters. Hydrogenation experiments of equimolar methyl oleate and elaidate mixtures at low temperature (65 °C) and high hydrogen pressure (6.0 MPa), using Pt catalysts, confirm this result. Only with a Pt/NaZSM-5 catalyst outspoken selectivity for the hydrogenation of the trans isomer is obtained. In order to prepare a selective Pt/ZSM-5 catalyst, the influence of Pt addition (impregnation, ion-exchange and competitive ion-exchange) and Pt activation (different calcination and reduction temperatures) on the Pt-distribution and Pt particle size was investigated using SEM, bright-field and HR TEM, EDX, electron tomography, CO-chemisorption, XPS, XRD, and UVvis measurements. The best result in terms of hydrogenation activity and selectivity is obtained with a Pt/ZSM-5 catalyst, which is prepared via competitive ion-exchange, followed by slow calcination up to 350 °C under high O2 flow and a reduction up to 500 °C under H2. This preparation method leads to a Pt/ZSM-5 catalyst with the best Pt distribution and the smallest Pt clusters occluded in the zeolite structure. Finally, the influence of zeolite crystal size, morphology, and elemental composition of ZSM-5 on hydrogenation activity and selectivity was investigated in detail.
Address
Corporate Author Thesis
Publisher Place of Publication San Diego, Calif. Editor
Language Wos 000275966100021 Publication Date 2010-01-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-9517; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.844 Times cited 24 Open Access
Notes FWO; IAP-IV; Methusalem Approved Most recent IF: 6.844; 2010 IF: 5.415
Call Number UA @ lucian @ c:irua:82435 Serial 2970
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Author Doria, M.M.; de Romaguera, A.R.C.; Peeters, F.M.
Title The ground states of the two-component order parameter superconductor Type A1 Journal article
Year 2010 Publication Europhysics letters Abbreviated Journal Epl-Europhys Lett
Volume 92 Issue (up) 1 Pages 17004
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We show that in presence of an applied external field the two-component order parameter superconductor falls in two categories of ground states, namely, in the traditional Abrikosov ground state or in a new ground state fitted to describe a superconducting layer with texture, that is, patched regions separated by a phase difference of pi. The existence of these two kinds of ground states follows from the sole assumption that the total supercurrent is the sum of the two individual supercurrents and is independent of any consideration about the free energy expansion. Uniquely defined relations between the current density and the superfluid density hold for these two ground states, which also determine the magnetization in terms of average values of the order parameters. Because these ground-state conditions are also Bogomolny equations we construct the free energy for the two-component superconductor which admits the Bogomolny solution at a special coupling value. Copyright (C) EPLA, 2010
Address
Corporate Author Thesis
Publisher Place of Publication Paris Editor
Language Wos 000284469900027 Publication Date 2010-10-30
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 8 Open Access
Notes ; ; Approved Most recent IF: 1.957; 2010 IF: 2.753
Call Number UA @ lucian @ c:irua:95558 Serial 3584
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Author Launois, P.; Chorro, M.; Verberck, B.; Albouy, P.-A.; Rouzière, S.; Colson, D.; Forget, A.; Noé, L.; Kataura, H.; Monthioux, M.; Cambedouzou, J.
Title Transformation of C70 peapods into double walled carbon nanotubes Type A1 Journal article
Year 2010 Publication Carbon Abbreviated Journal Carbon
Volume 48 Issue (up) 1 Pages 89-98
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract X-ray diffraction studies comparing the transformation of C(60) and C(70) peapods into double walled carbon nanotubes are presented. The structures of the as-formed DWCNTs are strikingly similar, showing that they are not dependent on the nature of the fullerene precursor. High temperature X-ray diffraction measurements of C(70) peapods below the coalescence temperature show that confined C(70) molecules in large tubes undergo an orientational. transition to free rotations. Fast re-orientations of C(70) molecules allow cyclo-addition between adjacent fullerenes to form, in good agreement with the mechanism of coalescence proposed in the literature for C(60) molecules. (C) 2009 Elsevier Ltd. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Oxford Editor
Language Wos 000272018800012 Publication Date 2009-08-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0008-6223; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.337 Times cited 27 Open Access
Notes ; ; Approved Most recent IF: 6.337; 2010 IF: 4.896
Call Number UA @ lucian @ c:irua:94389 Serial 3696
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Author Li, B.; Magnus, W.; Peeters, F.M.
Title Tunable exciton Aharonov-Bohm effect in a quantum ring Type A1 Journal article
Year 2010 Publication Journal of physics : conference series T2 – Proceedings of the 11th International Conference on Optics of Excitons in Confined Systems, September 7-11, 2009, Spain / Vina, L. [edit.]; et al. [edit.] Abbreviated Journal
Volume 210 Issue (up) 1 Pages 012030,1-01203,4
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We studied the optical Aharonov-Bohm effect for an exciton in a semiconductor quantum ring. A perpendicular electric field applied to a quantum ring with large height, is able to tune the exciton ground state energy such that it exhibits a weak observable Aharonov-Bohm oscillations. This Aharonov-Bohm effect is tunable in strength and period.
Address
Corporate Author Thesis
Publisher Place of Publication Bristol Editor
Language Wos 000289715800242 Publication Date 2010-03-03
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1742-6596; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 3 Open Access
Notes ; ; Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:89950 Serial 3741
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Author Worobiec, A.; Potgieter-Vermaak, S.; Brooker, A.; Darchuk, L.; Stefaniak, E.; Van Grieken, R.
Title Interfaced SEM/EDX and micro-Raman spectrometry for characterisation of heterogeneous environmental particles: fundamental and practical challenges Type A1 Journal article
Year 2010 Publication Microchemical journal Abbreviated Journal
Volume 94 Issue (up) 1 Pages 65-72
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Laboratory Experimental Medicine and Pediatrics (LEMP)
Abstract The molecular character of atmospheric particulate matter is of prime importance when interpreting air pollution trends and its subsequent influence on environmental monitoring and preventative conservation. The known methods of estimating the molecular composition normally involve elemental analysis of particles (both as bulk and computer controlled analyses of single particles) with subsequent multivariate analyses to clusterise the elements in groups of elements that are closely related to each other. With this approach one can at best suggest associations. Evidently the application of molecular spectroscopy in addition to elemental concentration profiles would provide intimate information regarding the nature of the particles and consequently their fate. This paper gives an overview of research performed in our laboratory and describes the optimisation of experimental parameters to use scanning electron microscopy with energy-dispersive X-ray detection (SEM/EDX) or electron probe X-ray microanalysis (EPXMA) in parallel with micro-Raman Spectrometry (MRS) to investigate single environmental particles. The challenges associated with the two stand-alone techniques are revealed and consequently those posed with an interfaced approach are discussed. Preliminary results, of an initial investigation of the SEM/EDX interfaced with MRS to ultra-fine heterogeneous environmental particles, are given.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000273238800011 Publication Date 2009-09-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0026-265x; 0026-265x 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:79801 Serial 8114
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Author Buysse, C.; Kovalevsky, A.; Snijkers, F.; Buekenhoudt, A.; Mullens, S.; Luyten, J.; Kretzschmar, J.; Lenaerts, S.
Title Fabrication and oxygen permeability of gastight, macrovoid-free Ba0.5Sr0.5Co0.8Fe0.2O3-\delta capillaries for high temperature gas separation Type A1 Journal article
Year 2010 Publication Journal of membrane science Abbreviated Journal J Membrane Sci
Volume 359 Issue (up) 1-2 Pages 86-92
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract Oxygen-permeable perovskites with mixed ionic-electronic conducting properties can play an important role in the separation of oxygen from air which is needed in the oxy-fuel and pre-combustion technologies for the removal and capture of CO2. In this work, gastight, macrovoid-free Ba0.5Sr0.5Co0.8Fe0.2O3−δ (BSCF) capillaries were successfully shaped by a phase-inversion spinning technique, followed by calcination and sintering. It was found that both the rheology of the ceramic suspension and the composition of bore liquid and coagulation bath are key factors for making macrovoid-free green capillaries. Gastight BSCF capillaries were obtained by sintering for 5 h at 1100 °C. The sintered BSCF capillaries contained a significant amount of BaSO4 due to a reaction with the polysulfone binder during calcination. The oxygen permeation flux through the BSCF capillaries was measured and compared to literature data on BSCF disk and hollow fiber membranes measured in similar conditions.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000279953300010 Publication Date 2009-10-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0376-7388 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.035 Times cited 38 Open Access
Notes ; The authors want to express their thanks to the VITO personnel for their continuous support, especially B. Molenberghs, W. Doyen, H. Beckers (Separation and Conversion Technology, VITO), R. Kemps, M. Mertens, I. Thijs, M. Schoeters, W. Bouwen and J. Cooymans (Materials Department, VITO). C. Buysse thankfully acknowledges a PhD scholarship provided by VITO and the University of Antwerp. This work is performed in the framework of the German Helmholtz Alliance Project “MEM-BRAIN”, aiming at the development of gas separation membranes for zero-emission fossil fuel power plants. ; Approved Most recent IF: 6.035; 2010 IF: 3.673
Call Number UA @ admin @ c:irua:82008 Serial 5950
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Author Lorenz, H.; Zhao, Q.; Turner, S.; Lebedev, O.I.; Van Tendeloo, G.; Kloetzer, B.; Rameshan, C.; Pfaller, K.
Title Origin of different deactivation of Pd/SnO2 and Pd/GeO2 catalysts in methanol dehydrogenation and reforming: a comparative study Type A1 Journal article
Year 2010 Publication Applied catalysis : A : general Abbreviated Journal Appl Catal A-Gen
Volume 381 Issue (up) 1/2 Pages 242-252
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Pd particles supported on SnO2 and GeO2 have been structurally investigated by X-ray diffraction, (High-Resolution) transmission and scanning electron microscopy after different reductive treatments to monitor the eventual formation of bimetallic phases and catalytically tested in methanol dehydrogenation/ reforming. For both oxides this included a thin film sample with well-defined Pd particles and a powder catalyst prepared by incipient wetness impregnation. The hexagonal and the tetragonal polymorph were studied for powder GeO2. Pd2Ge formation was observed on all GeO2-supported catalysts, strongly depending on the specific sample used. Reduction of the thin film at 573K resulted in full transformation into the bimetallic state. The partial solubility of hexagonal GeO2 in water and its thermal structural instability yielded Pd2Ge formation at 473 K, at the cost of a structurally inhomogeneous support and Ge metal formation at higher reduction temperatures. Pd on tetragonal GeO2 entered a state of strong metalsupport interaction after reduction at 573673 K, resulting in coalescing Pd2Ge particles on a sintered and re-crystallized support, apparently partially covering the bimetallic particles and decreasing the catalytic activity. Pd2Ge on amorphous thin film and hexagonal GeO2 converted methanol primarily via dehydrogenation to CO and H2. At 573 K, formation of Pd2Sn and also PdSn occurred on the Pd/SnO2 thin film. Pd3Sn2 (and to some extent Pd2Sn) were predominantly obtained on the respective powder catalyst. Strong deactivation with increasing reduction temperature was observed, likely not based on the classical strong metalsupport interaction effect, but rather on a combination of missing active structural ensembles on Sn-enriched bimetallic phases and the formation of metallic -Sn. Correlations to Pd and its bimetallics supported on ZnO, Ga2O3 and In2O3 were also discussed.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000279100700029 Publication Date 2010-04-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0926-860X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.339 Times cited 14 Open Access
Notes Esteem 026019 Approved Most recent IF: 4.339; 2010 IF: 3.384
Call Number UA @ lucian @ c:irua:83927 Serial 2522
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Author Peng, L.; Philippaerts, A.; Ke, X.; van Noyen, J.; de Cleppel, F.; Van Tendeloo, G.; Jacobs, P.A.; Sels, B.F.
Title Preparation of sulfonated ordered mesoporous carbon and its use for the esterification of fatty acids Type A1 Journal article
Year 2010 Publication Catalysis today Abbreviated Journal Catal Today
Volume 150 Issue (up) 1/2 Pages 140-146
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Mesoporous carbon, which can be replicated from mesoporous silica and whose surface is hydrophobic, can be an ideal catalyst for the esterification of fatty acids. Here we report an easy and low cost way to prepare sulfonic acid group-functionalized mesoporous carbon. A sample of calcined mesoporous silica SBA-15 was added to an aqueous sucrose solution followed by drying and calcination at different temperatures. In contrast to existing procedures, the obtained hybrid Si/C material was then first sulfonated in H2SO4, before the final removal of the silica template in order to stabilize the porous structure towards the liquid phase sulfonation treatment. Thus the silicacarbon composites, instead of the mesoporous carbon, were successfully sulfonated to introduce SO3H groups, while keeping the ordered mesoporous structure intact. The influence of carbonization temperature was investigated, suggesting an optimum temperature of 873 K. The SO3H group-functionalized mesoporous carbon, denoted as CMK-3-873-SO3H, was characterized by means of XRD, N2 physisorption, SEM, FT-IR, elemental analysis and TEM. It followed that a uniform mesoporous carbon was obtained with an average pore size of 3.89 nm, a specific surface of 807 m2/g and a SO3H group loading of 0.39 meq/g of dry material. Compared with other solid acid catalysts, the resulting material shows enhanced activity in the acid-catalyzed esterification of oleic acid with methanol, and can be used repeatedly. The increased catalytic performance is attributed to the hydrophobic surface and larger pore size of the new catalyst. It can effectively accommodate long chain fatty acids and reject formed water, making the active sites easily accessible.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000275566700024 Publication Date 2009-09-04
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0920-5861; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.636 Times cited 132 Open Access
Notes Approved Most recent IF: 4.636; 2010 IF: 2.993
Call Number UA @ lucian @ c:irua:81739 Serial 2706
Permanent link to this record
 
 
Author Lorenz, H.; Turner, S.; Lebedev, O.I.; Van Tendeloo, G.; Klötzer, B.; Rameshan, C.; Pfaller, K.; Penner, S.
Title Pd-In2O3 interaction due to reduction in hydrogen: consequences for methanol steam reforming Type A1 Journal article
Year 2010 Publication Applied catalysis : A : general Abbreviated Journal Appl Catal A-Gen
Volume 374 Issue (up) 1/2 Pages 180-188
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Two different Pd/In2O3 samples including a thin film model catalyst with well-defined Pd particles grown on NaCl(0 0 1) supports and a powder catalyst prepared by an impregnation technique are examined by electron microscopy, X-ray diffraction and catalytic measurements in methanol steam reforming in order to correlate the formation of different oxide-supported bimetallic PdIn phases with catalytic activity and selectivity. A PdIn shell around the Pd particles is observed on the thin film catalyst after embedding the Pd particles in In2O3 at 300 K, likely because alloying to PdIn and oxidation to In2O3 are competing processes. Increased PdIn bimetallic formation is observed up to 573 K reduction temperature until at 623 K the film stability limit in hydrogen is reached. Oxidative treatments at 573 K lead to decomposition of PdIn and to the formation of an In2O3 shell covering the Pd particles, which irreversibly changes the activity and selectivity pattern to clean In2O3. PdIn and Pd2In3 phases are obtained on the powder catalyst after reduction at 573 K and 673 K, respectively. Only CO2-selective methanol steam reforming is observed in the reduction temperature range between 473 K and 573 K. After reduction at 673 K encapsulation of the bimetallic particles by crystalline In2O3 suppresses CO2 formation and only activity and selectivity of clean In2O3 are measured.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000274869900023 Publication Date 2009-12-18
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0926-860X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.339 Times cited 55 Open Access
Notes Esteem 026019 Approved Most recent IF: 4.339; 2010 IF: 3.384
Call Number UA @ lucian @ c:irua:81801 Serial 3553
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Author Verlooy, P.L.H.; Robeyns, K.; van Meervelt, L.; Lebedev, O.I.; Van Tendeloo, G.; Martens, J.A.; Kirschhock, C.E.A.
Title Synthesis and characterization of the new cyclosilicate hydrate (hexamethyleneimine)4.[Si8O16(OH)4].12H2O Type A1 Journal article
Year 2010 Publication Microporous and mesoporous materials: zeolites, clays, carbons and related materials Abbreviated Journal Micropor Mesopor Mat
Volume 130 Issue (up) 1/3 Pages 14-20
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract A new cyclosilicate hydrate with composition (C6H14N)4·[Si8O16(OH)4]·12H2O was crystallized and the structure determined by single-crystal X-ray diffraction. The structure, described by the tetragonal space group I41/a, with unit cell dimensions of a = 39.2150(2) Å and c = 14.1553(2) Å, contains columns of hydrogen-bonded cubic octamer silicate anions. The space between silicate columns holds hydrogen-bonded water and protonated hexamethyleneimine molecules compensating the negative charge of the silicate. The crystal water can be removed resulting in a rearrangement of the columns into orthorhombic symmetry. Removal of the organic moiety causes amorphisation. Flash evacuation results in a new microporous material with pore volumes typical of a zeolite.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000275702600003 Publication Date 2009-10-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1387-1811; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.615 Times cited 5 Open Access
Notes Approved Most recent IF: 3.615; 2010 IF: 3.220
Call Number UA @ lucian @ c:irua:82448 Serial 3418
Permanent link to this record
 
 
Author Damla, N.; Čevik, U.; Kobya, A.I.; Celik, A.; Celik, N.; Van Grieken, R.
Title Radiation dose estimation and mass attenuation coefficients of cement samples used in Turkey Type A1 Journal article
Year 2010 Publication Journal of hazardous materials Abbreviated Journal
Volume 176 Issue (up) 1/3 Pages 644-649
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract Different cement samples commonly used in building construction in Turkey have been analyzed for natural radioactivity using gamma-ray spectrometry. The mean activity concentrations observed in the cement samples were 52, 40 and 324 Bq kg−1 for 226Ra, 232Th and 40K, respectively. The measured activity concentrations for these radionuclides were compared with the reported data of other countries and world average limits. The radiological hazard parameters such as radium equivalent activities (Raeq), gamma index (Iγ) and alpha index (Iα) indices as well as terrestrial absorbed dose and annual effective dose rate were calculated and compared with the international data. The Raeq values of cement are lower than the limit of 370 Bq kg−1, equivalent to a gamma dose of 1.5 mSv y−1. Moreover, the mass attenuation coefficients were determined experimentally and calculated theoretically using XCOM in some cement samples. Also, chemical compositions analyses of the cement samples were investigated.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000274839700087 Publication Date 2009-11-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3894 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:80671 Serial 8448
Permanent link to this record
 
 
Author Delville, R.; Kasinathan, S.; Zhang, Z.; van Humbeeck, J.; James, R.D.; Schryvers, D.
Title Transmission electron microscopy study of phase compatibility in low hysteresis shape memory alloys Type A1 Journal article
Year 2010 Publication Philosophical magazine Abbreviated Journal Philos Mag
Volume 90 Issue (up) 1/4 Pages 177-195
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Recent findings have linked low hysteresis in shape memory alloys with phase compatibility between austenite and martensite. To investigate the evolution of microstructure as phase compatibility increases and hysteresis is reduced, transmission electron microscopy was used to study the alloy system Ti50Ni50xPdx, where the composition is systemically tuned to approach perfect compatibility. Changes in morphology, twinning density and twinning modes are reported, along with special microstructures occurring when compatibility is achieved. In addition, the interface between austenite and a single variant of martensite was studied by high-resolution and conventional electron microscopy. The low energy configuration of the interface detailed in this article suggests that it plays an important role in the lowering of hysteresis compared to classical habit plane interfaces.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000274576500013 Publication Date 2010-01-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1478-6435;1478-6443; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.505 Times cited 70 Open Access
Notes Multimat; FWO Approved Most recent IF: 1.505; 2010 IF: 1.304
Call Number UA @ lucian @ c:irua:79859 Serial 3718
Permanent link to this record
 
 
Author Li, Y.; Yang, X.-Y.; Tian, G.; Vantomme, A.; Yu, J.; Van Tendeloo, G.; Su, B.-L.
Title Chemistry of trimethyl aluminum: a spontaneous route to thermally stable 3D crystalline macroporous alumina foams with a hierarchy of pore sizes Type A1 Journal article
Year 2010 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume 22 Issue (up) 10 Pages 3251-3258
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract A simple and spontaneous one-pot self-formation procedure that is easy to scale up has been developed based on the chemistry of trimethylaluminum (TMA), leading to thermally stable macroporous crystalline alumina with a very unique and unprecedented three-dimensional (3D) hierarchical pore structure consisting of well-defined wormlike mesopores. TMA is the precursor of both product and porogene (viz, two working functions within the same molecule (2 in 1)). The materials obtained have been intensively characterized by powder X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), N2 adsorption−desorption, and mercury porosimetry. The open cagelike macrocavities are self-constructed by mesoporous nanorods (diameter of ca. 40−70 nm), which are themselves formed by a random assembly of fibrous nanoparticles 5−6 nm in size. Optical microscopy (OM) has been used in situ to follow the synthesis procedure, which led to the proposal of the formation mechanism. Methane molecules as porogens, which were instantaneously released because of the fast hydrolysis of the chemical precursor, were the key factor in producing these 3D structures with uniform co-continuous macropores that interconnected directly with the wormlike mesopores. The important characteristic of this procedure is the concurrent formation of a multiscaled porous network. The material exhibits great thermal stability. The hierarchically mesoporous−macroporous Al2O3 obtained is quite attractive for a myriad of applications, from catalysis to biomedicine. The present work illustrates that the one-pot self-formation concept, based on the chemistry of alkyl metals, is a versatile method to design industrially valuable hierarchically porous materials.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000277635000030 Publication Date 2010-04-27
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 38 Open Access
Notes Approved Most recent IF: 9.466; 2010 IF: 6.400
Call Number UA @ lucian @ c:irua:82760 Serial 356
Permanent link to this record
 
 
Author Khaydarov, R.T.; Beisinbaeva, H.B.; Sabitov, M.M.; Kalal, M.; Berdiyorov, G.R.
Title Conditions defining the mechanisms of the formation of light gas ions in multicomponent laser-produced plasmas Type A1 Journal article
Year 2010 Publication Nuclear fusion Abbreviated Journal Nucl Fusion
Volume 50 Issue (up) 10 Pages 105007,1-105007,4
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Using the mass-spectrometric method we study the charge, energy and spatial characteristics of ions in multicomponent plasma, generated under the action of Nd : YAG laser radiation on the surface of solid targets. We focus on the effect of the entry form of light gas atoms on the parameters of ions in such laser-produced plasmas. We found that the presence of light gas atoms considerably affects the parameters (e.g. the intensity and the charge multiplicity) of the heavier ions.
Address
Corporate Author Thesis
Publisher Place of Publication Vienna Editor
Language Wos 000281859300008 Publication Date 2010-08-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0029-5515;1741-4326; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.307 Times cited 1 Open Access
Notes ; ; Approved Most recent IF: 3.307; 2010 IF: 3.303
Call Number UA @ lucian @ c:irua:84876 Serial 476
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Author Yiu, H.H.P.; Niu, H.-jun; Biermans, E.; Van Tendeloo, G.; Rosseinsky, M.J.
Title Designed multifunctional nanocomposites for biomedical applications Type A1 Journal article
Year 2010 Publication Advanced functional materials Abbreviated Journal Adv Funct Mater
Volume 20 Issue (up) 10 Pages 1599-1609
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The assembly of multifunctional nanocomposite materials is demonstrated by exploiting the molecular sieving property of SBA-16 nanoporous silica and using it as a template material. The cages of the pore networks are used to host iron oxide magnetic nanoparticles, leaving a pore volume of 0.29 cm3 g-1 accessible for drug storage. This iron oxide-silica nanocomposite is then functionalized with amine groups. Finally the outside of the particle is decorated with antibodies. Since the size of many protein molecules, including that of antibodies, is too large to enter the pore system of SBA-16, the amine groups inside the pores are preserved for drug binding. This is proven using a fluorescent protein, fluorescein-isothiocyanate-labeled bovine serum albumin (FITC-BSA), with the unreacted amine groups inside the pores dyed with rhodamine B isothiocyanate (RITC). The resulting nanocomposite material offers a dual-targeting drug delivery mechanism, i.e., magnetic and antibody-targeting, while the functionalization approach is extendable to other applications, e.g., fluorescence-magnetic dual-imaging diagnosis.
Address
Corporate Author Thesis
Publisher Place of Publication Weinheim Editor
Language Wos 000278597100008 Publication Date 2010-04-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1616-301X;1616-3028; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 12.124 Times cited 56 Open Access
Notes Approved Most recent IF: 12.124; 2010 IF: 8.508
Call Number UA @ lucian @ c:irua:83298 Serial 662
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Author Shanenko, A.A.; Croitoru, M.D.; Vagov, A.; Peeters, F.M.
Title Giant drop in the Bardeen-Cooper-Schrieffer coherence length induced by quantum size effects in superconducting nanowires Type A1 Journal article
Year 2010 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 82 Issue (up) 10 Pages 104524-104524,6
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The BCS coherence length in low-dimensional superconductors is dramatically modified by quantum-size effects. In particular, for nanowires made of conventional superconducting materials, we show that the longitudinal zero-temperature coherence length exhibits width-dependent drops by 23 orders of magnitude each time when the bottom of one of single-electron subbands formed due to the transverse quantization of electron motion is situated in a close vicinity to the Fermi level. This phenomenon has strong similarities to the well-known BCS-BEC (Bose-Einstein condensation) crossover in ultracold fermionic condensates but with an important exception: it is driven by the transverse quantization of the electron motion rather than by the externally controlled strength of the fermion-fermion interaction.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000282269600005 Publication Date 2010-09-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 29 Open Access
Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), and the ESF-network: INSTANS. M. D. C. acknowledges support from the Alexander von Humboldt Foundation. A. A. S. thanks R. G. Mints, W. V. Pogosov, D. Y. Vodolazov, A. Perali, and A. Bianconi for fruitful discussions. ; Approved Most recent IF: 3.836; 2010 IF: 3.774
Call Number UA @ lucian @ c:irua:85419 Serial 1337
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Author Quintana, M.; Ke, X.; Van Tendeloo, G.; Meneghetti, M.; Bittencourt, C.; Prato, M.
Title Light-induced selective deposition of Au nanoparticles on single-wall carbon nanotubes Type A1 Journal article
Year 2010 Publication ACS nano Abbreviated Journal Acs Nano
Volume 4 Issue (up) 10 Pages 6105-6113
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Novel applications of single-walled carbon nanotubes (SWNT) rely on the development of new strategies to make them easier to handle without affecting their structural properties. In this work, we have selectively deposited Au nanoparticles (Au NP) on SWNT assisted by UV light irradiation. XPS analysis and UV-vis spectroscopy indicate that the deposition occurs at the defects generated after oxidation of the SWNT. By addition of n-dodecylthiol, the separation of oxidized tubes with Au NP (Au-ox-SWNT) from tubes devoid of Au NP (bare tubes, b-SWNT) was achieved. Raman and UV-vis-NIR spectra indicate that UV irradiation induces a faster nucleation of Au NP on metallic SWNT. This new technique can be useful for the preparation of nanohybrid composites with enhanced properties, as increased thermal stability, and to obtain purified SWNT.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000283453700081 Publication Date 2010-09-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1936-0851;1936-086X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 13.942 Times cited 26 Open Access
Notes Approved Most recent IF: 13.942; 2010 IF: 9.865
Call Number UA @ lucian @ c:irua:99202 Serial 1819
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Author Jian-Ping, N.; Xiao-Dan, L.; Cheng-Li, Z.; You-Min, Q.; Ping-Ni, H.; Bogaerts, A.; Fu-Jun, G.
Title Molecular dynamics simulation of temperature effects on CF(3)(+) etching of Si surface Type A1 Journal article
Year 2010 Publication Wuli xuebao Abbreviated Journal Acta Phys Sin-Ch Ed
Volume 59 Issue (up) 10 Pages 7225-7231
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Molecular dynamics method was employed to investigate the effects of the reaction layer formed near the surface region on CF(3)(+) etching of Si at different temperatures. The simulation results show that the coverages of F and C are sensitive to the surface temperature. With increasing temperature, the physical etching is enhanced, while the chemical etching is weakened. It is found that with increasing surface temperature, the etching rate of Si increases. As to the etching products, the yields of SiF and SiF(2) increase with temperature, whereas the yield of SiF(3) is not sensitive to the surface temperature. And the increase of the etching yield is mainly due to the increased desorption of SiF and SiF(2). The comparison shows that the reactive layer plays an important part in the subsequeat impacting, which enhances the etching rate of Si and weakens the chemical etching intensity.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date 0000-00-00
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1000-3290 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 0.624 Times cited Open Access
Notes Approved Most recent IF: 0.624; 2010 IF: 1.259
Call Number UA @ lucian @ c:irua:95564 Serial 2171
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Author Schapotschnikow, P.; van Huis, M.A.; Zandbergen, H.W.; Vanmaekelbergh, D.; Vlugt, T.J.H.
Title Morphological transformations and fusion of PbSe nanocrystals studied using atomistic simulations Type A1 Journal article
Year 2010 Publication Nano letters Abbreviated Journal Nano Lett
Volume 10 Issue (up) 10 Pages 3966-3971
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Molecular dynamics simulations are performed on capped and uncapped PbSe nanocrystals, employing newly developed classical interaction potentials. Here, we show that two uncapped nanocrystals fuse efficiently via direct surface attachment, even if they are initially misaligned. In sharp contrast to the general belief, interparticle dipole interactions do not play a significant role in this oriented attachment process. Furthermore, it is shown that presumably polar, capped PbSe{111} facets are never fully Pb- or Se-terminated.
Address
Corporate Author Thesis
Publisher Place of Publication Washington Editor
Language Wos 000282727600028 Publication Date 2010-09-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1530-6984;1530-6992; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 12.712 Times cited 59 Open Access
Notes Approved Most recent IF: 12.712; 2010 IF: 12.219
Call Number UA @ lucian @ c:irua:84902 Serial 2205
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Author Idrissi, H.; Renard, K.; Schryvers, D.; Jacques, P.J.
Title On the relationship between the twin internal structure and the work-hardening rate of TWIP steels Type A1 Journal article
Year 2010 Publication Scripta materialia Abbreviated Journal Scripta Mater
Volume 63 Issue (up) 10 Pages 961-964
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract FeMnC and FeMnSiAl TWIP steels deformed under the same conditions exhibit different work-hardening rates. The present study investigates the microstructure of plastically deformed FeMnC and FeMnSiAl samples, particularly the internal structure of the mechanically generated twins and their topology at the grain scale. Twins in the FeMnC steel are finer and full of sessile dislocations, rendering this material distinctly stronger with an improved work-hardening rate.
Address
Corporate Author Thesis
Publisher Place of Publication Oxford Editor
Language Wos 000282461800003 Publication Date 2010-07-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1359-6462; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.747 Times cited 145 Open Access
Notes Iap Approved Most recent IF: 3.747; 2010 IF: 2.820
Call Number UA @ lucian @ c:irua:84472 Serial 2452
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Author Doria, M.M.; Romaguera, A.R. de C.; Peeters, F.M.
Title Vortex patterns in a mesoscopic superconducting rod with a magnetic dot Type A1 Journal article
Year 2010 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 81 Issue (up) 10 Pages 104529,1-104529,11
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We study a mesoscopic superconducting rod with a magnetic dot on its top having its moment oriented along the axis of symmetry. We study the dependence of the vortex pattern with the height and find that for very short and very long rods, the vortex pattern acquires a simple structure, consisting of giant and of multivortex states, respectively. In the long limit, the most stable configuration consists of two vortices, that reach the lateral surface of the rod diametrically opposed. The long rod shows reentrant behavior within some range of its radius and of the dots magnetic moment. Our results are obtained within the Ginzburg-Landau approach in the limit of no magnetic shielding.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000276248700123 Publication Date 2010-03-31
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 5 Open Access
Notes ; The three authors acknowledge CNPq and the bilateral program between Brazil and Flanders for financial support. They also make the following acknowledgments for financial support: A. R. de C. Romaguera to FACEPE, M. M. Doria to FAPERJ, and F. M. Peeters to the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IUAP), and the ESF-AQDJJ network. ; Approved Most recent IF: 3.836; 2010 IF: 3.774
Call Number UA @ lucian @ c:irua:82272 Serial 3877
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Author Yang, T.; Perkisas, T.; Hadermann, J.; Croft, M.; Ignatov, A.; Greenblatt, M.
Title B-site ordered perovskite LaSrMnNbO6 : synthesis, structure and antiferromagnetism Type A1 Journal article
Year 2010 Publication Journal of solid state chemistry Abbreviated Journal J Solid State Chem
Volume 183 Issue (up) 11 Pages 2689-2694
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract LaSrMnNbO6 has been synthesized by high temperature solid state reaction under 1% H2/Ar dynamic flow. The structure is determined by Rietveld refinement of the powder X-ray diffraction data. It crystallizes in the monoclinic space group P21/n with the unit cell parameters: a=5.69187(12), b=5.74732(10), c=8.07018(15) Å and β=90.0504(29)°, which were also confirmed by electron diffraction. The Mn2+ and Nb5+ ions, whose valence states are confirmed by X-ray absorption near-edge spectroscopy, are almost completely ordered over the B-site (<1% inversion) of the perovskite structure due to the large differences of both cationic size (0.19 Å) and charge. The octahedral framework displays significant tilting distortion according to Glazers tilt system a−b−c+. Upon heating, LaSrMnNbO6 decomposes at 690 °C under O2 flow or at 775 °C in air. The magnetic susceptibility data indicate the presence of long-range antiferromagnetic ordering at TN=8 K; the experimentally observed effective paramagnetic moment, μeff=5.76 μB for high spin Mn2+ (3d5, S=5/2) is in good agreement with the calculated value (μcalcd=5.92 μB).
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000284179800028 Publication Date 2010-09-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-4596; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.299 Times cited 13 Open Access
Notes Esteem 026019 Approved Most recent IF: 2.299; 2010 IF: 2.261
Call Number UA @ lucian @ c:irua:85805 Serial 212
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Author Neyts, E.C.; Shibuta, Y.; van Duin, A.C.T.; Bogaerts, A.
Title Catalyzed growth of carbon nanotube with definable chirality by hybrid molecular dynamics-force biased Monte Carlo simulations Type A1 Journal article
Year 2010 Publication ACS nano Abbreviated Journal Acs Nano
Volume 4 Issue (up) 11 Pages 6665-6672
Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Metal-catalyzed growth mechanisms of carbon nanotubes (CNTs) were studied by hybrid molecular dynamics−Monte Carlo simulations using a recently developed ReaxFF reactive force field. Using this novel approach, including relaxation effects, a CNT with definable chirality is obtained, and a step-by-step atomistic description of the nucleation process is presented. Both root and tip growth mechanisms are observed. The importance of the relaxation of the network is highlighted by the observed healing of defects.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000284438000043 Publication Date 2010-10-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1936-0851;1936-086X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 13.942 Times cited 129 Open Access
Notes Approved Most recent IF: 13.942; 2010 IF: 9.865
Call Number UA @ lucian @ c:irua:84759 Serial 294
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Author Zhang, Y.-R.; Xu, X.; Zhao, S.-X.; Bogaerts, A.; Wang, Y.-N.
Title Comparison of electrostatic and electromagnetic simulations for very high frequency plasmas Type A1 Journal article
Year 2010 Publication Physics of plasmas Abbreviated Journal Phys Plasmas
Volume 17 Issue (up) 11 Pages 113512-113512,11
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract A two-dimensional self-consistent fluid model combined with the full set of Maxwell equations is developed to investigate an argon capacitively coupled plasma, focusing on the electromagnetic effects on the discharge characteristics at various discharge conditions. The results indicate that there exist distinct differences in plasma characteristics calculated with the so-called electrostatic model (i.e., without taking into account the electromagnetic effects) and the electromagnetic model (which includes the electromagnetic effects), especially at very high frequencies. Indeed, when the excitation source is in the high frequency regime and the electromagnetic effects are taken into account, the plasma density increases significantly and meanwhile the ionization rate evolves to a very different distribution when the electromagnetic effects are dominant. Furthermore, the dependence of the plasma characteristics on the voltage and pressure is also investigated, at constant frequency. It is observed that when the voltage is low, the difference between these two models becomes more obvious than at higher voltages. As the pressure increases, the plasma density profiles obtained from the electromagnetic model smoothly shift from edge-peaked over uniform to a broad maximum in the center. In addition, the edge effect becomes less pronounced with increasing frequency and pressure, and the skin effect rather than the standing-wave effect becomes dominant when the voltage is high.
Address
Corporate Author Thesis
Publisher Place of Publication Woodbury, N.Y. Editor
Language Wos 000285486500105 Publication Date 2010-11-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1070-664X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.115 Times cited 30 Open Access
Notes Approved Most recent IF: 2.115; 2010 IF: 2.320
Call Number UA @ lucian @ c:irua:84763 Serial 429
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Author Wu, Z.; Peeters, F.M.; Chang, K.
Title Electron tunneling through double magnetic barriers on the surface of a topological insulator Type A1 Journal article
Year 2010 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 82 Issue (up) 11 Pages 115211-115211,7
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We study electron tunneling through a planar magnetic and electric barrier on the surface of a three-dimensional topological insulator. For the double barrier structures, we find (i) a directional-dependent tunneling which is sensitive to the magnetic field configuration and the electric gate voltage, (ii) a spin rotation controlled by the magnetic field and the gate voltage, (iii) many Fabry-Pérot resonances in the transmission determined by the distance between the two barriers, and (iv) the electrostatic potential can enhance the difference in the transmission between the two magnetization configurations, and consequently lead to a giant magnetoresistance. Points (i), (iii), and (iv) are alike with that in graphene stemming from the same linear-dispersion relations.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000282125700002 Publication Date 2010-09-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 65 Open Access
Notes ; This work was supported by the NSF of China, the Flemish Science Foundation (FWO-Vl), and the Belgian Science Policy. ; Approved Most recent IF: 3.836; 2010 IF: 3.774
Call Number UA @ lucian @ c:irua:85420 Serial 990
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Author Peelaers, H.; Partoens, B.; Peeters, F.M.
Title Electronic and dynamical properties of Si/Ge core-shell nanowires Type A1 Journal article
Year 2010 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 82 Issue (up) 11 Pages 113411-113411,4
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Full ab initio techniques are applied to study the electronic and dynamical properties of free standing, hydrogen-passivated Si/Ge core-shell nanowires oriented along the [110] direction. All studied wires exhibit a direct band gap and are found to be structurally stable. The different contributions of the core and shell atoms to the phonon spectra are identified. The acoustic phonon velocities and the frequencies of some typical optical modes are compared with those of pure Si and Ge nanowires. These depend either on the concentration or on the type of core material. Optical modes are hardened and longitudinal acoustic velocities are softened with decreasing wire diameter.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000282270000001 Publication Date 2010-09-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 13 Open Access
Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), and NOI-BOF (University of Antwerp). ; Approved Most recent IF: 3.836; 2010 IF: 3.774
Call Number UA @ lucian @ c:irua:85421 Serial 995
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Author Masir, M.R.; Vasilopoulos, P.; Peeters, F.M.
Title Fabry-Pérot resonances in graphene microstructures: influence of a magnetic field Type A1 Journal article
Year 2010 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 82 Issue (up) 11 Pages 115417-115417,12
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Fabry-Pérot resonances in the transmission through single and double, graphene-based barriers (of height V) and wells are investigated and their dependence on an applied perpendicular magnetic field. For rectangular barriers the conductance decreases with increasing magnetic field while the resonances weaken (become more pronounced) with increasing magnetic field for EF<V (EF>V). The position of the resonances exhibit a linear shift with magnetic field which move to lower (higher) energy for EF<V (EF>V). Compared to semielliptic- or Gaussian-shaped barriers they show a smaller number of resonances in the absence of a magnetic field and an overall lower conductance but the resonant structure is more pronounced. The conductance of asymmetric double barriers show two major regions of resonances while the symmetric ones show one, that of three asymmetric barriers three, and so on.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000281723100007 Publication Date 2010-09-10
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 74 Open Access
Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP) and the Canadian NSERC under Grant No. OGP0121756. ; Approved Most recent IF: 3.836; 2010 IF: 3.774
Call Number UA @ lucian @ c:irua:84871 Serial 1167
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Author Xu, T.; Nys, J.-P.; Addad, A.; Lebedev, O.I.; Urbieta, A.; Salhi, B.; Berthe, M.; Grandidier, B.; Stievenard, D.
Title Faceted sidewalls of silicon nanowires: Au-induced structural reconstructions and electronic properties Type A1 Journal article
Year 2010 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 81 Issue (up) 11 Pages 115403,1-115403,10
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Si nanowires with a ⟨111⟩ orientation, synthesized by vapor-liquid-solid process with low silane partial pressure reactant and gold as the catalyst, are known to exhibit sawtooth facets containing gold adsorbates. We report herein the study of the nanowire morphology by means of transmission electron microscopy and scanning tunneling microscopy. The nanowires consist of faceted sidewalls. The number of the sidewalls changes from 12 to 6 along the growth axis, giving rise to nanowires with an irregular hexagonal cross section at their base. The sidewalls are covered with Au-rich clusters. Their facets also exhibit atomic structures that reveal the presence of gold, resulting from the diffusion of gold during the growth. Based on these observations, the tapering of the nanowire is found to be related to two contributions: the reduction in the catalyst particle size during the growth and lateral overgrowth from the direct incorporation of Si species onto the nanowire sidewalls. Because the rearrangement of atoms at surfaces and interfaces might affect the growth kinetics, the trigonal symmetry as well as the higher lateral growth rate on the widest sidewalls are explained from the existence of an interfacial atomic structure with two inequivalent parts in the unit cell. Finally, spectroscopic measurements were performed on the major facets and revealed a metallic behavior at 77 K.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000276248800116 Publication Date 2010-03-03
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 42 Open Access
Notes Approved Most recent IF: 3.836; 2010 IF: 3.774
Call Number UA @ lucian @ c:irua:82273 Serial 1168
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