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Author Sébilleau, D.; Natoli, C.; Gavaza, G.M.; Zhao, H.; da Pieve, F.; Hatada, K.
Title MsSpec-1.0 : a multiple scattering package for electron spectroscopies in material science Type (up) A1 Journal article
Year 2011 Publication Computer physics communications Abbreviated Journal Comput Phys Commun
Volume 182 Issue 12 Pages 2567-2579
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract We present a multiple scattering package to calculate the cross-section of various spectroscopies namely photoelectron diffraction (PED), Auger electron diffraction (AED), X-ray absorption (XAS), low-energy electron diffraction (LEED) and Auger photoelectron coincidence spectroscopy (APECS). This package is composed of three main codes, computing respectively the cluster, the potential and the cross-section. In the latter case, in order to cover a range of energies as wide as possible, three different algorithms are provided to perform the multiple scattering calculation: full matrix inversion, series expansion or correlation expansion of the multiple scattering matrix. Numerous other small Fortran codes or bash/csh shell scripts are also provided to perform specific tasks. The cross-section code is built by the user from a library of subroutines using a makefile.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000295769700014 Publication Date 2011-07-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0010-4655; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.936 Times cited 6 Open Access
Notes Approved Most recent IF: 3.936; 2011 IF: 3.268
Call Number UA @ lucian @ c:irua:93288 Serial 2208
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Author Lindner, H.; Bogaerts, A.
Title Multi-element model for the simulation of inductively coupled plasmas : effects of helium addition to the central gas stream Type (up) A1 Journal article
Year 2011 Publication Spectrochimica acta: part B : atomic spectroscopy Abbreviated Journal Spectrochim Acta B
Volume 66 Issue 6 Pages 421-431
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract A model for an atmospheric pressure inductively coupled plasma (ICP) is developed which allows rather easy extension to a variable number of species and ionisation degrees. This encompasses an easy calculation of transport parameters for mixtures, ionisation and heat capacity. The ICP is modeled in an axisymmetric geometry, taking into account the gas streaming into a flowing ambient gas. A mixture of argon and helium is applied in the injector gas stream as it is often done in laser ablation ICP spectrometry. The results show a strong influence of the added helium on the center of the ICP, which is important for chemical analysis. The length of the central channel is significantly increased and the temperature inside is significantly higher than in the case of pure argon. This means that higher gas volume flow rates can be applied by addition of helium compared to the use of pure argon. This has the advantage that the gas velocity in the transport system towards the ICP can be increased, which allows shorter washout-times. Consequently, shorter measurement times can be achieved, e.g. for spatial mapping analyses in laser ablation ICP spectrometry. Furthermore, the higher temperature and the longer effective plasma length will increase the maximum size of droplets or particles injected into the ICP that are completely evaporated at the detection site. Thus, we expect an increase of the analytical performance of the ICP by helium addition to the injector gas.
Address
Corporate Author Thesis
Publisher Place of Publication Oxford Editor
Language Wos 000293488700003 Publication Date 2011-04-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0584-8547; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.241 Times cited 28 Open Access
Notes Approved Most recent IF: 3.241; 2011 IF: 2.876
Call Number UA @ lucian @ c:irua:90190 Serial 2209
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Author Chen, L.-H.; Li, X.-Y.; Tian, G.; Li, Y.; Tan, H.-Y.; Van Tendeloo, G.; Zhu, G.-S.; Qiu, S.-L.; Yang, X.-Y.; Su, B.-L.
Title Multimodal zeolite-beta-based catalysts with a hierarchical, three-level pore structure Type (up) A1 Journal article
Year 2011 Publication Chemsuschem Abbreviated Journal Chemsuschem
Volume 4 Issue 10 Pages 1452-1456
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Hole diggers: The hierarchically structured porous solid-acid catalyst described in this report possess a remarkable pore system, encompassing well-defined macrochannels, interconnected mesopores, intracrystalline mesopores, and tunable zeolite micropores. Importantly, the catalyst exhibits very strong acidity and superior catalytic activity for esterification reactions.
Address
Corporate Author Thesis
Publisher Place of Publication Weinheim Editor
Language Wos 000296497400009 Publication Date 2011-08-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1864-5631; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 7.226 Times cited 33 Open Access
Notes Iap Approved Most recent IF: 7.226; 2011 IF: 6.827
Call Number UA @ lucian @ c:irua:93675 Serial 2223
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Author Lobato, I.; Partoens, B.
Title Multiple Dirac particles in AA-stacked graphite and multilayers of graphene Type (up) A1 Journal article
Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 83 Issue 16 Pages 165429-165429,9
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
Abstract Using the tight-binding formalism we show that in the recently experimentally realized AA-stacked graphite in essence two types of massless relativistic Dirac particles are present with a different effective speed of light. We also investigate how the electronic structure evolves from a single graphene sheet into AA-stacked graphite. It is shown that in contrast to AB-stacked graphene layers, the spectrum of AA-stacked graphene layers can be considered as a superposition of single-layer spectra and only particles with a linear spectrum at the Fermi energy around the K point are present. From the evolution of the band overlap we show that 6 multilayers of AA-stacked graphene already behave as AA-stacked graphite. The evolution of the effective speeds of light of the Dirac particles to their bulk values shows exactly the same behavior. The tight-binding parameters we use to describe AA-stacked graphite and multilayers of graphene are obtained by ab initio calculations.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000290113900005 Publication Date 2011-04-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 68 Open Access
Notes ; ; Approved Most recent IF: 3.836; 2011 IF: 3.691
Call Number UA @ lucian @ c:irua:89717 Serial 2225
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Author Tian, H.; Schryvers, D.; Claeys, P.
Title Nanodiamonds do not provide unique evidence for a Younger Dryas impact Type (up) A1 Journal article
Year 2011 Publication Proceedings of the National Academy of Sciences of the United States of America Abbreviated Journal P Natl Acad Sci Usa
Volume 108 Issue 1 Pages 40-44
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Microstructural, δ13C isotope and C/N ratio investigations were conducted on excavated material from the black Younger Dryas boundary in Lommel, Belgium, aiming for a characterisation of the carbon content and structures. Cubic diamond nanoparticles are found in large numbers. The larger ones with diameters around or above 10 nm often exhibit single or multiple twins. The smaller ones around 5 nm in diameter are mostly defect-free. Also larger flake-like particles, around 100 nm in lateral dimension, with a cubic diamond structure are observed as well as large carbon onion structures. The combination of these characteristics does not yield unique evidence for an exogenic impact related to the investigated layer.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000285915000012 Publication Date 2010-12-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0027-8424;1091-6490; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.661 Times cited 32 Open Access
Notes Approved Most recent IF: 9.661; 2011 IF: 9.681
Call Number UA @ lucian @ c:irua:88733 Serial 2254
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Author Prituzhalov, V.A.; Ardashnikova, E.I.; Vinogradov, A.A.; Dolgikh, V.A.; Videau, J.-J.; Fargin, E.; Abakumov, A.M.; Tarakina, N.V.; Van Tendeloo, G.
Title New anion-conducting solid solutions Bi1-xTex(O,F)2+\delta (x > 0.5) and glassceramic material on their base Type (up) A1 Journal article
Year 2011 Publication Journal of fluorine chemistry Abbreviated Journal J Fluorine Chem
Volume 132 Issue 12 Pages 1110-1116
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The anion-excess fluorite-like solid solutions with general composition Bi1−xTex(O,F)2+δ (x > 0.5) have been synthesized by a solid state reaction of TeO2, BiF3 and Bi2O3 at 873 K with following quenching. The homogeneity areas and polymorphism of the I ↔ IV Bi1−xTex(O,F)2+δ phases were investigated. The crystal structure of the low temperature IV-Bi1−xTex(O,F)2+δ phase has been solved using electron diffraction and X-ray powder diffraction (a = 11.53051(9) Å, S.G. Ia-3, RI = 0.046, RP = 0.041). Glass formation area in the Bi2O3BiF3TeO2 (10% TiO2) system was investigated. IVBi1−xTex(O,F)2+δ phase starts to crystallize at short-time (0.53 h) annealing of oxyfluoride glasses at temperatures above Tg (600615 K). The ionic conductivity of the crystalline Bi1−xTex(O,F)2+δ phase and corresponding glass-ceramics was investigated. Activation energy of conductivity Ea = 0.41(2) eV for the IV-Bi1−xTex(O,F)2+δ crystalline samples and Ea = 0.73 eV for the glass-ceramic samples were obtained. Investigation of the oxyfluoride samples with a constant cation ratio demonstrates essential influence of excess fluorine anions on the ionic conductivity.
Address
Corporate Author Thesis
Publisher Place of Publication Lausanne Editor
Language Wos 000296936300011 Publication Date 2011-07-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-1139; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.101 Times cited 2 Open Access
Notes Approved Most recent IF: 2.101; 2011 IF: 2.033
Call Number UA @ lucian @ c:irua:93687 Serial 2305
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Author Vernimmen, J.; Meynen, V.; Herregods, S.J.F.; Mertens, M.; Lebedev, O.I.; Van Tendeloo, G.; Cool, P.
Title New insights in the formation of combined zeolitic/mesoporous materials by using a one-pot templating synthesis Type (up) A1 Journal article
Year 2011 Publication European journal of inorganic chemistry Abbreviated Journal Eur J Inorg Chem
Volume Issue 27 Pages 4234-4240
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA)
Abstract Zeolitic growth is often absent or occurs in separate phases when synthetic strategies based on the combination of zeolite templates and mesopore templating agents are applied. In this work, zeolitic growth and mesopore formation have been investigated at different temperatures by applying a one-pot templating approach, based on a TS-1 zeolite synthesis whereby part of the microtemplate (tetrapropylammonium hydroxide, TPAOH) is replaced by a mesotemplate (hexadecyltrimethylammonium bromide, CTMABr). Moreover, the synthesis duration and the molar ratio of the microtemplate/mesotemplate have also been studied. The different syntheses clearly show the inherent competitive mechanism between zeolitic growth and mesopore formation. These insights have led to the conclusion that by following a one-pot templating strategy with standard, nonexotic commercial templates, i.e. CTMABr and TPAOH, it is not possible to develop a true hierarchical mesoporous zeolite, meaning a mesoporous siliceous material with highly crystalline zeolitic walls. The resultant materials are instead combined zeolitic/mesoporous composite structures with, however, highly tuneable and controllable porosity characteristics.
Address
Corporate Author Thesis
Publisher Place of Publication Weinheim Editor
Language Wos 000296143500014 Publication Date 2011-08-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-1948; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.444 Times cited 7 Open Access
Notes Fwo Approved Most recent IF: 2.444; 2011 IF: 3.049
Call Number UA @ lucian @ c:irua:91574 Serial 2315
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Author Afanasov, I.M.; Lebedev, O.I.; Kolozhvary, B.A.; Smirnov, A.V.,; Van Tendeloo, G.
Title Nickel/carbon composite materials based on expanded graphite Type (up) A1 Journal article
Year 2011 Publication New carbon materials Abbreviated Journal
Volume 26 Issue 5 Pages 335-340
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Monolithic nickel/carbon (Ni/C) composites were prepared from coal tar pitch-impregnated compressed expanded graphite pre-decorated with NiO particles (EGNiO) by pyrolysis at 550 °C and subsequent steam activation at 800 °C. The microstructural arrangement of the Ni-comprising nanoparticles in the composites was investigated using transmission electron microscopy. The specific surface area and porosity of the composites were analyzed by nitrogen adsorption. The catalytic activity of the composites was compared with the material obtained by the conventional H2 treatment of EGNiO using hydrocracking of 2,2,3-trimethylpentane as a model reaction.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000296926500003 Publication Date 2011-11-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1872-5805; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 7 Open Access
Notes Iap Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:93633 Serial 2340
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Author Shenderova, O.A.; Vlasov, I.I.; Turner, S.; Van Tendeloo, G.; Orlinskii, S.B.; Shiryaev, A.A.; Khomich, A.A.; Sulyanov, S.N.; Jelezko, F.; Wrachtrup, J.
Title Nitrogen control in nanodiamond produced by detonation shock-wave-assisted synthesis Type (up) A1 Journal article
Year 2011 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
Volume 115 Issue 29 Pages 14014-14024
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Development of efficient production methods of nanodiamond (ND) particles containing substitutional nitrogen and nitrogen-vacancy (NV) complexes remains an important goal in the nanodiamond community. ND synthesized from explosives is generally not among the preferred candidates for imaging applications owing to lack of optically active particles containing NV centers. In this paper, we have systematically studied representative classes of NDs produced by detonation shock wave conversion of different carbon precursor materials, namely, graphite and a graphite/hexogen mixture into ND, as well as ND produced from different combinations of explosives using different cooling methods (wet or dry cooling). We demonstrate that (i) the N content in nanodiamond particles can be controlled through a correct selection of the carbon precursor material (addition of graphite, explosives composition); (ii) particles larger than approximately 20 nm may contain in situ produced optically active NV centers, and (iii) in ND produced from explosives, NV centers are detected only in ND produced by wet synthesis. ND synthesized from a mixture of graphite/explosive contains the largest amount of NV centers formed during synthesis and thus deserves special attention.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000292892500009 Publication Date 2011-06-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-7447;1932-7455; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.536 Times cited 54 Open Access
Notes Esteem 026019; Fwo Approved Most recent IF: 4.536; 2011 IF: 4.805
Call Number UA @ lucian @ c:irua:91259 Serial 2342
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Author Mao, M.; Wang, Y.N.; Bogaerts, A.
Title Numerical study of the plasma chemistry in inductively coupled SF6 and SF6/AR plasmas used for deep silicon etching applications Type (up) A1 Journal article
Year 2011 Publication Journal of physics: D: applied physics Abbreviated Journal J Phys D Appl Phys
Volume 44 Issue 43 Pages 435202,1-435202,15
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract A hybrid model, called the hybrid plasma equipment model, was used to study inductively coupled SF6 plasmas used for Si etching applications. The plasma properties such as number densities of electrons, positive and negative ions, and neutrals are calculated under typical etching conditions. The electron kinetics is analysed by means of the electron energy probability function. The plasma chemistry taking place in pure SF6 and in an Ar/SF6 mixture is also discussed, and finally the effect of the argon fraction on the plasma properties is investigated.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000296591100004 Publication Date 2011-10-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-3727;1361-6463; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.588 Times cited 20 Open Access
Notes Approved Most recent IF: 2.588; 2011 IF: 2.544
Call Number UA @ lucian @ c:irua:91754 Serial 2409
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Author Gélard, J.; Jehanathan, N.; Roussel, H.; Gariglio, S.; Lebedev, O.I.; Van Tendeloo, G.; Dubourdieu, C.
Title Off-stoichiometry effects on the crystalline and defect structure of hexagonal manganite REMnO3 films (RE = Y, Er, Dy) Type (up) A1 Journal article
Year 2011 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume 23 Issue 5 Pages 1232-1238
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The crystalline and defect structure of epitaxial hexagonal RExMnyO3 (RE = Er, Dy) films with varying cationic composition was investigated by X-ray diffraction and transmission electron microscopy. The films are composed of a strained layer at the interface with the substrate and of a relaxed layer on top of it. The critical thickness is of 10 to 25 nm. For Mn-rich films (or RE deficient), an off-stoichiometric composition maintaining the hexagonal LuMnO3-type structure is stabilized over a large range of the RE/Mn ratio (0.72−1.00), with no Mn-rich secondary phases observed. A linear dependence of the out-of-plane lattice parameter with RE/Mn is observed in this range. Out-of-phase boundary (OPB) extended defects are observed in all films and exhibit a local change in stoichiometry. Such a large solubility limit in the RE deficient region points toward the formation of vacancies on the RE site (RExMnO3−δ, with 0.72 ≤ x < 1), a phenomenon that is encountered in perovskite manganites such as LaxMnO3−δ (x < 1) and that may strongly impact the physical properties of hexagonal manganites.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000287767200022 Publication Date 2011-02-03
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 17 Open Access
Notes Approved Most recent IF: 9.466; 2011 IF: 7.286
Call Number UA @ lucian @ c:irua:88649 Serial 2430
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Author Boschker, H.; Huijben, M.; Vailinois, A.; Verbeeck, J.; Van Aert, S.; Luysberg, M.; Bals, S.; Van Tendeloo, G.; Houwman, E.P.; Koster, G.; Blank, D.H.A.; Rijnders, G.
Title Optimized fabrication of high-quality La0.67Sr0.33MnO3 thin films considering all essential characteristics Type (up) A1 Journal article
Year 2011 Publication Journal of physics: D: applied physics Abbreviated Journal J Phys D Appl Phys
Volume 44 Issue 20 Pages 205001-205001,9
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract In this paper, an overview of the fabrication and properties of high-quality La0.67Sr0.33MnO3 (LSMO) thin films is given. A high-quality LSMO film combines a smooth surface morphology with a large magnetization and a small residual resistivity, while avoiding precipitates and surface segregation. In the literature, typically only a few of these issues are adressed. We therefore present a thorough characterization of our films, which were grown by pulsed laser deposition. The films were characterized with reflection high energy electron diffraction, atomic force microscopy, x-ray diffraction, magnetization and transport measurements, x-ray photoelectron spectroscopy and scanning transmission electron microscopy. The films have a saturation magnetization of 4.0 µB/Mn, a Curie temperature of 350 K and a residual resistivity of 60 µΩ cm. These results indicate that high-quality films, combining both large magnetization and small residual resistivity, were realized. A comparison between different samples presented in the literature shows that focussing on a single property is insufficient for the optimization of the deposition process. For high-quality films, all properties have to be adressed. For LSMO devices, the thin-film quality is crucial for the device performance. Therefore, this research is important for the application of LSMO in devices.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000290150900001 Publication Date 2011-04-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-3727;1361-6463; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.588 Times cited 99 Open Access
Notes This research was financially supported by the Dutch Science Foundation, by NanoNed, a nanotechnology program of the Dutch Ministry of Economic Affairs, and by the NanOxide program of the European Science Foundation. This work is supported in part by the Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering, under contract DE-AC02-76SF00515. Approved Most recent IF: 2.588; 2011 IF: 2.544
Call Number UA @ lucian @ c:irua:89557UA @ admin @ c:irua:89557 Serial 2491
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Author Verberck, B.
Title Orientational properties of C70 and C80 fullerenes in carbon nanotubes Type (up) A1 Journal article
Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 83 Issue 4 Pages 045405-045405,8
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We present energy calculations of a C80 molecule with D5d symmetry encapsulated in a carbon nanotube. The approximation of a continuous tube rather than a rolled-up graphene sheet, justified by comparison with atomistic calculations, allows an expansion of the energy field into symmetry-adapted rotator functions. For a given tube radius R, we observe a strong dependence of the interaction energy on the molecular tilt angle and on the molecules lateral position in the tube. We observe a transition from on-axis lying orientations to tilted orientations at R1≈6.95 Å and a subsequent transition to standing orientations at R2≈7.6 Å. For tube radii larger than R3≈8.0 Å, the molecule starts to occupy off-axis positions and assumes a lying orientation. Results are compared to the case of C70 molecules, with D5h symmetry. Our findings are consistent with recent high-resolution transmission electron microscopy measurements and are relevant for the design of new materials with tunable electronic properties.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000286770600010 Publication Date 2011-01-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 6 Open Access
Notes ; The author gratefully acknowledges discussions with A. V. Nikolaev and K. H. Michel. This work was financially supported by the Research Foundation-Flanders (FWO-Vl). ; Approved Most recent IF: 3.836; 2011 IF: 3.691
Call Number UA @ lucian @ c:irua:88911 Serial 2520
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Author Vodolazov, D.Y.; Peeters, F.M.
Title Origin of the hysteresis of the current voltage characteristics of superconducting microbridges near the critical temperature Type (up) A1 Journal article
Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 84 Issue 9 Pages 094511
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The current voltage (IV) characteristics of short [with length L less than or similar to xi(T)] and long [L >> xi(T)] microbridges are theoretically investigated near the critical temperature of the superconductor. Calculations are made in the nonlocal (local) limit when the inelastic relaxation length due to electron-phonon interactions L(in) = (D tau(in))(1/2) is larger (smaller) than the temperature-dependent coherence length xi(T) (D is the diffusion coefficient, tau(in) is the inelastic relaxation time of the quasiparticle distribution function). We find that, in both limits, the origin of the hysteresis in the IV characteristics is mainly connected with the large time scale over which the magnitude of the order parameter varies in comparison with the time-scale variation of the superconducting phase difference across the microbridge in the resistive state. In the nonlocal limit, the time-averaged heating and cooling of quasiparticles are found in different areas of the microbridge, which are driven, respectively, by oscillations of the order parameter and the electric field. We show that, by introducing an additional term in the time-dependent Ginzburg-Landau equation, it is possible to take into account the cooling effect in the local limit too.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000294920900009 Publication Date 2011-09-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 7 Open Access
Notes ; This work was supported by the Russian Foundation for Basic Research, Russian Agency of Education under the Federal Target Programme“Scientific and educational personnel of innovative Russia in 2009-2013,” the Flemish Science Foundation (FWO-Vl), and the Belgian Science Policy (IAP). ; Approved Most recent IF: 3.836; 2011 IF: 3.691
Call Number UA @ lucian @ c:irua:105573 Serial 2527
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Author Croitoru, M.D.; Shanenko, A.A.; Peeters, F.M.; Axt, V.M.
Title Parity-fluctuation induced enlargement of the ratio \DeltaE/kBTc in metallic grains Type (up) A1 Journal article
Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 84 Issue 21 Pages 214518-214518,12
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We investigate how the interplay of quantum confinement and particle number-parity fluctuations affects superconducting correlations in ultra-small metallic grains. Using the number-parity projected BCS formalism we calculate the critical temperature and the excitation gap as a function of the grain size for grains with even and odd number of confined carriers. We show that the experimentally observed anomalous increase of the coupling ratio ΔE/kBTc with decreasing superconducting grain size can be attributed to an enhancement of the number-parity fluctuations in ultra-small grains.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000298114100003 Publication Date 2011-12-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 14 Open Access
Notes ; This work was supported by the European Community under a Marie Curie IEF Action (Grant Agreement No. PIEF-GA-2009-235486-ScQSR), the Flamish Science Foundation (FWO-Vl), and the Belgian Science Policy (IAP). M. D. C. thanks A. S. Mel'nikov and N. B. Kopnin for fruitful discussions. ; Approved Most recent IF: 3.836; 2011 IF: 3.691
Call Number UA @ lucian @ c:irua:94373 Serial 2555
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Author Tsirlin, A.A.; Nath, R.; Abakumov, A.M.; Furukawa, Y.; Johnston, D.C.; Hemmida, M.; Krug von Nidda, H.-A.; Loidl, A.; Geibel, C.; Rosner, H.
Title Phase separation and frustrated square lattice magnetism of Na1.5VOPO4F0.5 Type (up) A1 Journal article
Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 84 Issue 1 Pages 014429-014429,16
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Crystal structure, electronic structure, and magnetic behavior of the spin-1/2 quantum magnet Na1.5VOPO4F0.5 are reported. The disorder of Na atoms leads to a sequence of structural phase transitions revealed by synchrotron x-ray powder diffraction and electron diffraction. The high-temperature second-order α↔β transition at 500 K is of the order-disorder type, whereas the low-temperature β↔γ+γ′ transition around 250 K is of the first order and leads to a phase separation toward the polymorphs with long-range (γ) and short-range (γ′) order of Na. Despite the complex structural changes, the magnetic behavior of Na1.5VOPO4F0.5 probed by magnetic susceptibility, heat capacity, and electron spin resonance measurements is well described by the regular frustrated square lattice model of the high-temperature α-polymorph. The averaged nearest-neighbor and next-nearest-neighbor couplings are J̅ 1≃−3.7 K and J̅ 2≃6.6 K, respectively. Nuclear magnetic resonance further reveals the long-range ordering at TN=2.6 K in low magnetic fields. Although the experimental data are consistent with the simplified square-lattice description, band structure calculations suggest that the ordering of Na atoms introduces a large number of inequivalent exchange couplings that split the square lattice into plaquettes. Additionally, the direct connection between the vanadium polyhedra induces an unusually strong interlayer coupling having effect on the transition entropy and the transition anomaly in the specific heat. Peculiar features of the low-temperature crystal structure and the relation to isostructural materials suggest Na1.5VOPO4F0.5 as a parent compound for the experimental study of tetramerized square lattices as well as frustrated square lattices with different values of spin.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000293247400008 Publication Date 2011-07-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 47 Open Access
Notes Approved Most recent IF: 3.836; 2011 IF: 3.691
Call Number UA @ lucian @ c:irua:91770 Serial 2588
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Author Michel, K.H.; Verberck, B.
Title Phonon dispersions and piezoelectricity in bulk and multilayers of hexagonal boron nitride Type (up) A1 Journal article
Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 83 Issue 11 Pages 115328-115328,14
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract A unified theory of phonon dispersions and piezoelectricity in bulk and multilayers of hexagonal boron nitride (h-BN) is derived. The dynamical matrix is calculated on the basis of an empirical force constant model of intralayer valence and interlayer van der Waals interactions. Coulomb interactions are calculated by Ewalds method, adapted for the three-dimensional (3D) and the multilayer case. The deformation of the ionic charge distribution with long-wave lattice displacements is taken into account. Special attention is devoted to the nonanalytic long-range Coulomb contribution to the dynamical matrix which is different for the 3D crystal and the multilayer case. Consequently there is a splitting of the transverse optical (TO) and longitudinal optical (LO) phonon branches of E1u symmetry and a discontinuity of the A2u branch at the Γ point in 3D h-BN. No such splitting and discontinuity at Γ are present in multilayer crystals with a finite number N of layers. There a diverging bundle of N overbending optical phonon branches emerges from Γ. Borns long-wave theory is applied and extended for the study of piezoelectricity in layered crystals. While 3D h-BN and h-BN multilayers with an even number of layers (symmetry D6h) are not piezoelectric, multilayers with an uneven number of Nu layers (symmetry D3h) are piezoelectric; the piezoelectric coefficient e1,11 is inversely proportional to Nu.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000288783700005 Publication Date 2011-03-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 82 Open Access
Notes ; Discussions with G. Heger, B. Partoens, and F. M. Peeters are gratefully acknowledged. This work has been supported by the Flemish Science Foundation (FWO-V1) and the Bijzonder Onderzoeksfonds, Universiteit Antwerpen (BOF-UA). ; Approved Most recent IF: 3.836; 2011 IF: 3.691
Call Number UA @ lucian @ c:irua:89602 Serial 2603
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Author Simon, Q.; Barreca, D.; Bekermann, D.; Gasparotto, A.; Maccato, C.; Comini, E.; Gombac, V.; Fornasiero, P.; Lebedev, O.I.; Turner, S.; Devi, A.; Fischer, R.A.; Van Tendeloo, G.
Title Plasma-assisted synthesis of Ag/ZnO nanocomposites : first example of photo-induced H2 production and sensing Type (up) A1 Journal article
Year 2011 Publication International journal of hydrogen energy Abbreviated Journal Int J Hydrogen Energ
Volume 36 Issue 24 Pages 15527-15537
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Ag/ZnO nanocomposites were developed by a plasma-assisted approach. The adopted strategy exploits the advantages of Plasma Enhanced-Chemical Vapor Deposition (PE-CVD) for the growth of columnar ZnO arrays on Si(100) and Al2O3 substrates, in synergy with the infiltration power of the Radio Frequency (RF)-sputtering technique for the subsequent dispersion of different amounts of Ag nanoparticles (NPs). The resulting composites, both as-prepared and after annealing in air, were thoroughly characterized with particular attention on their morphological organization, structure and composition. For the first time, the above systems have been used as catalysts in the production of hydrogen by photo-reforming of alcoholic solutions, yielding a stable H2 evolution even by the sole use of simulated solar radiation. In addition, Ag/ZnO nanocomposites presented an excellent response in the gas-phase detection of H2, opening attractive perspectives for advanced technological applications.
Address
Corporate Author Thesis
Publisher Place of Publication Oxford Editor
Language Wos 000297089700006 Publication Date 2011-10-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0360-3199; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.582 Times cited 62 Open Access
Notes Esteem 026019; Fwo Approved Most recent IF: 3.582; 2011 IF: 4.054
Call Number UA @ lucian @ c:irua:91901 Serial 2627
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Author Mao, M.; Bogaerts, A.
Title Plasma chemistry modeling for an inductively coupled plasma used for the growth of carbon nanotubes Type (up) A1 Journal article
Year 2011 Publication Journal of physics : conference series Abbreviated Journal
Volume 275 Issue 1 Pages 012021,1-012021,9
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract A hybrid model, called the hybrid plasma equipment model (HPEM), is used to describe the plasma chemistry in an inductively coupled plasma, operating in a gas mixture of C2H2 with either H2 or NH3, as typically used for carbon nanotube (CNT) growth. Two-dimensional profiles of power density, electron temperature and density, gas temperature, and densities of some plasma species are plotted and analyzed. Besides, the fluxes of the various plasma species towards the substrate (where the CNTs can be grown), as well as the decomposition rates of the feedstock gases (C2H2, NH3 and H2), are calculated as a function of the C2H2 fraction in both gas mixtures.
Address
Corporate Author Thesis
Publisher Place of Publication Bristol Editor
Language Wos Publication Date 2011-02-09
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:85859 Serial 2631
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Author Idrissi, H.; Turner, S.; Mitsuhara, M.; Wang, B.; Hata, S.; Coulombier, M.; Raskin, J.-P.; Pardoen, T.; Van Tendeloo, G.; Schryvers, D.
Title Point defect clusters and dislocations in FIB irradiated nanocrystalline aluminum films : an electron tomography and aberration-corrected high-resolution ADF-STEM study Type (up) A1 Journal article
Year 2011 Publication Microscopy and microanalysis Abbreviated Journal Microsc Microanal
Volume 17 Issue 6 Pages 983-990
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Focused ion beam (FIB) induced damage in nanocrystalline Al thin films has been characterized using advanced transmission electron microscopy techniques. Electron tomography was used to analyze the three-dimensional distribution of point defect clusters induced by FIB milling, as well as their interaction with preexisting dislocations generated by internal stresses in the Al films. The atomic structure of interstitial Frank loops induced by irradiation, as well as the core structure of Frank dislocations, has been resolved with aberration-corrected high-resolution annular dark-field scanning TEM. The combination of both techniques constitutes a powerful tool for the study of the intrinsic structural properties of point defect clusters as well as the interaction of these defects with preexisting or deformation dislocations in irradiated bulk or nanostructured materials.
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge, Mass. Editor
Language Wos 000297832300018 Publication Date 2011-10-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1431-9276;1435-8115; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.891 Times cited 25 Open Access
Notes Iap; Fwo Approved Most recent IF: 1.891; 2011 IF: 3.007
Call Number UA @ lucian @ c:irua:93627 Serial 2653
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Author Heidari Mezerji, H.; van den Broek, W.; Bals, S.
Title A practical method to determine the effective resolution in incoherent experimental electron tomography Type (up) A1 Journal article
Year 2011 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 111 Issue 5 Pages 330-336
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Abstract It is not straightforward to determine resolution for a 3D reconstruction when performing an electron tomography experiment. Different contributions such as missing wedge and misalignment add up and often influence the final resolution in an anisotropic manner. The conventional resolution measures can not be used for all of the reconstruction techniques, especially for iterative techniques which are more commonly used for electron tomography in materials science. Here we define a quantitative resolution measure that determines the resolution in three orthogonal directions of the reconstruction. As an application we use this measure to determine the optimum number of simultaneous iterative reconstruction technique (SIRT) iterations to reconstruct the gold nanoparticles, based on a high angle annular dark field STEM (HAADF-STEM) tilt series.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000289396900005 Publication Date 2011-01-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.843 Times cited 26 Open Access
Notes Esteem 026019; Fwo Approved Most recent IF: 2.843; 2011 IF: 2.471
Call Number UA @ lucian @ c:irua:87606 Serial 2688
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Author Wouters, J.; Lebedev, O.I.; Van Tendeloo, G.; Yamada, H.; Sato, N.; Vanacken, J.; Moshchalkov, V.V.; Verbiest, T.; Valev, V.K.
Title Preparing polymer films doped with magnetic nanoparticles by spin-coating and melt-processing can induce an in-plane magnetic anisotropy Type (up) A1 Journal article
Year 2011 Publication Journal of applied physics Abbreviated Journal J Appl Phys
Volume 109 Issue 7 Pages 076105-076105,3
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Faraday rotation has been used to investigate a series of polymer films doped with magnetic iron oxide nanoparticles. The films have been prepared by spin-coating and melt-processing. In each case, upon varying the angle of optical incidence on the films, an in-plane magnetic anisotropy is observed. The effect of such an anisotropy on the Faraday rotation as a function of the angle of optical incidence is verified by comparison with magnetically poled films. These results demonstrate that care should be taken upon analyzing the magnetic behavior of such films on account of the sample preparation techniques themselves being able to affect the magnetization.
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000289949000166 Publication Date 2011-04-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-8979; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.068 Times cited 10 Open Access
Notes Fwo; Iap; Iwt Approved Most recent IF: 2.068; 2011 IF: 2.168
Call Number UA @ lucian @ c:irua:89917 Serial 2709
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Author Cao, S.; Nishida, M.; Schryvers, D.
Title Quantitative three-dimensional analysis of Ni4Ti3 precipitate morphology and distribution in polycrystalline Ni-Ti Type (up) A1 Journal article
Year 2011 Publication Acta materialia Abbreviated Journal Acta Mater
Volume 59 Issue 4 Pages 1780-1789
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The three-dimensional size, morphology and distribution of Ni4Ti3 precipitates in a Ni50.8Ti49.2 polycrystalline shape memory alloy with a heterogeneous microstructure have been investigated using a focused ion beam/scanning electron microscopy slice-and-view procedure. The mean volume, central plane diameter, thickness, aspect ratio and sphericity of the precipitates in the grain interior as well as near to the grain boundary were measured and/or calculated. The morphology of the precipitates was quantified by determining the equivalent ellipsoids with the same moments of inertia and classified according to the Zingg scheme. Also, the pair distribution functions describing the three-dimensional distributions were obtained from the coordinates of the precipitate mass centres. Based on this new data it is suggested that the existence of the heterogeneous microstructure could be due to a very small concentration gradient in the grains of the homogenized material and that the resulting multistage martensitic transformation originates in strain effects related to the size of the precipitates and scale differences of the available B2 matrix in between the precipitates.
Address
Corporate Author Thesis
Publisher Place of Publication Oxford Editor
Language Wos 000287265100045 Publication Date 2010-12-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1359-6454; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 5.301 Times cited 34 Open Access
Notes Fwo Approved Most recent IF: 5.301; 2011 IF: 3.755
Call Number UA @ lucian @ c:irua:85533 Serial 2766
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Author Sels, D.; Sorée, B.; Groeseneken, G.
Title Quantum ballistic transport in the junctionless nanowire pinch-off field effect transistor Type (up) A1 Journal article
Year 2011 Publication Journal of computational electronics Abbreviated Journal J Comput Electron
Volume 10 Issue 1 Pages 216-221
Keywords A1 Journal article; Theory of quantum systems and complex systems; Condensed Matter Theory (CMT)
Abstract In this work we investigate quantum ballistic transport in ultrasmall junctionless and inversion mode semiconducting nanowire transistors within the framework of the self-consistent Schrödinger-Poisson problem. The quantum transmitting boundary method is used to generate open boundary conditions between the active region and the electron reservoirs. We adopt a subband decomposition approach to make the problem numerically tractable and make a comparison of four different numerical approaches to solve the self-consistent Schrödinger-Poisson problem. Finally we discuss the IV-characteristics for small (r≤5 nm) GaAs nanowire transistors. The novel junctionless pinch-off FET or junctionless nanowire transistor is extensively compared with the gate-all-around (GAA) nanowire MOSFET.
Address
Corporate Author Thesis
Publisher Place of Publication S.l. Editor
Language Wos 000300735800021 Publication Date 2011-02-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1569-8025;1572-8137; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.526 Times cited 12 Open Access
Notes ; ; Approved Most recent IF: 1.526; 2011 IF: 1.211
Call Number UA @ lucian @ c:irua:89501 Serial 2772
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Author Shestakov, M.V.; Tikhomirov, V.K.; Kirilenko, D.; Kuznetsov, A.S.; Chibotaru, L.F.; Baranov, A.N.; Van Tendeloo, G.; Moshchalkov, V.V.
Title Quantum cutting in Li (770 nm) and Yb (1000 nm) co-dopant emission bands by energy transfer from the ZnO nano-crystalline host Type (up) A1 Journal article
Year 2011 Publication Optics express Abbreviated Journal Opt Express
Volume 19 Issue 17 Pages 15955-15964
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Li-Yb co-doped nano-crystalline ZnO has been synthesized by a method of thermal growth from the salt mixtures. X-ray diffraction, transmission electron microscopy, atomic absorption spectroscopy and optical spectroscopy confirm the doping and indicate that the dopants may form Li-Li and Yb3+-Li based nanoclusters. When pumped into the conduction and exciton absorption bands of ZnO between 250 to 425 nm, broad emission bands of about 100 nm half-height-width are excited around 770 and 1000 nm, due to Li and Yb dopants, respectively. These emission bands are activated by energy transfer from the ZnO host mostly by quantum cutting processes, which generate pairs of quanta in Li (770 nm) and Yb (1000 nm) emission bands, respectively, out of one quantum absorbed by the ZnO host. These quantum cutting phenomena have great potential for application in the down-conversion layers coupled to the Si solar cells.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000293894900033 Publication Date 2011-08-04
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1094-4087; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.307 Times cited 19 Open Access
Notes FWO; Methusalem Approved Most recent IF: 3.307; 2011 IF: 3.587
Call Number UA @ lucian @ c:irua:92428 Serial 2776
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Author Krüger, P.; da Pieve, F.; Osterwalder, J.
Title Real-space multiple scattering method for angle-resolved photoemission and valence-band photoelectron diffraction and its application to Cu(111) Type (up) A1 Journal article
Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 83 Issue 11 Pages 115437,1-115437,8
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract A computational method is presented for angle-resolved photoemission spectra (ARPES) and photoelectron diffraction (PED) in the ultraviolet regime. The one-step model is employed and both initial valence and final continuum states are calculated using the finite-cluster, real-space multiple scattering method. Thereby the approach is versatile and provides a natural link to core-level PED. The method is applied to the Cu(111) valence band and good agreement with experiment is found for both ARPES spectra and PED patterns. When the PED patterns are integrated over a filled band of a single-orbital symmetry, such as Cu-3d, we show, both numerically and analytically, that the exact theory with delocalized initial states can be replaced by the much simpler, core-level-type theory where the initial states are taken as localized.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000288594500005 Publication Date 2011-03-22
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 17 Open Access
Notes Approved Most recent IF: 3.836; 2011 IF: 3.691
Call Number UA @ lucian @ c:irua:89599 Serial 2831
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Author Berdiyorov, G.R.; Milošević, M.V.; Covaci, L.; Peeters, F.M.
Title Rectification by an imprinted phase in a Josephson junction Type (up) A1 Journal article
Year 2011 Publication Physical review letters Abbreviated Journal Phys Rev Lett
Volume 107 Issue 17 Pages 177008-177008,5
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract A Josephson phase shift can be induced in a Josephson junction by a strategically nearby pinned Abrikosov vortex (AV). For an asymmetric distribution of an imprinted phase along the junction (controlled by the position of the AV) such a simple system is capable of rectification of ac current in a broad and tunable frequency range. The resulting rectified voltage is a consequence of the directed motion of a Josephson antivortex which forms a pair with the AV when at local equilibrium. The proposed realization of the ratchet potential by an imprinted phase is more efficient than the asymmetric geometry of the junction itself, is easily realizable experimentally, and provides rectification even in the absence of an applied magnetic field.
Address
Corporate Author Thesis
Publisher Place of Publication New York, N.Y. Editor
Language Wos 000296985000008 Publication Date 2011-10-21
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 28 Open Access
Notes ; This work was supported by the Flemish Science Foundation (FWO-Vlaanderen) and the Belgian Science Policy (IAP). G. R. B. and L. C. acknowledge individual support from FWO-Vlaanderen. ; Approved Most recent IF: 8.462; 2011 IF: 7.370
Call Number UA @ lucian @ c:irua:93715 Serial 2847
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Author Lin, N.S.; Heitmann, T.W.; Yu, K.; Plourde, B.L.T.; Misko, V.R.
Title Rectification of vortex motion in a circular ratchet channel Type (up) A1 Journal article
Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 84 Issue 14 Pages 144511-144511,12
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We study the dynamics of vortices in an asymmetric (i.e., consisting of triangular cells) ring channel driven by an external ac current I in a Corbino setup. The asymmetric potential rectifies the motion of vortices and induces a net vortex flow without any unbiased external drive, i.e., the ratchet effect. We show that the net flow of vortices strongly depends on vortex density and frequency of the driving current. Depending on the density, we distinguish a single-vortex rectification regime (for low density, when each vortex is rectified individually) determined by the potential-energy landscape inside each cell of the channel (i.e., hard and easy directions) and multi-vortex, or collective, rectification (high-density case) when the inter-vortex interaction becomes important. We analyze the average angular velocity ω of vortices as a function of I and study commensurability effects between the numbers of vortices and cells in the channel and the role of frequency of the applied ac current. We have shown that the commensurability effect results in a stepwise ω-I curve. Besides the integer steps, i.e., the large steps found in the single-vortex case, we also found fractional steps corresponding to fractional ratios between the numbers of vortices and triangular cells. We have performed preliminary measurements on a device containing a single weak-pinning circular ratchet channel in a Corbino geometry and observed a substantial asymmetric vortex response.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000295795500010 Publication Date 2011-10-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 27 Open Access
Notes ; We thank Peter Kes and Marcel Hesselberth for providing the superconducting films from which the Corbino ratchet sample was fabricated. This work was supported by the “Odysseus” Program of the Flemish Government and the Flemish Science Foundation (FWO-Vl), the Interuniversity Attraction Poles (IAP) Programme-Belgian State-Belgian Science Policy, and the FWO-Vl (Belgium). T. W. H., K.Y., and B. L. T. P acknowledge support from the National Science Foundation under Grant DMR-0547147 as well as the use of the Cornell NanoScale Facility, a member of the National Nanotechnology Infrastructure Network, which is supported by the National Science Foundation (Grant ECS-0335765). ; Approved Most recent IF: 3.836; 2011 IF: 3.691
Call Number UA @ lucian @ c:irua:92809 Serial 2848
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Author Zelaya, E.; Schryvers, D.
Title Reducing the formation of FIB-induced FCC layers on Cu-Zn-Al austenite Type (up) A1 Journal article
Year 2011 Publication Microscopy research and technique Abbreviated Journal Microsc Res Techniq
Volume 74 Issue 1 Pages 84-91
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The irradiation effects of thinning a sample of a Cu-Zn-Al shape memory alloy to electron transparency by a Ga+ focused ion beam were investigated. This thinning method was compared with conventional electropolishing and Ar+ ion milling. No implanted Ga was detected but surface FCC precipitation was found as a result of the focused ion beam sample preparation. Decreasing the irradiation dose by lowering the energy and current of the Ga+ ions did not lead to a complete disappearance of the FCC structure. The latter could only be removed after gentle Ar+ ion milling of the sample. It was further concluded that the precipitation of the FCC is independent of the crystallographic orientation of the surface.
Address
Corporate Author Thesis
Publisher Place of Publication New York, N.Y. Editor
Language Wos 000285976000012 Publication Date 2010-05-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1059-910X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.147 Times cited 2 Open Access
Notes Approved Most recent IF: 1.147; 2011 IF: 1.792
Call Number UA @ lucian @ c:irua:85994 Serial 2852
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Author Kalkert, C.; Krisponeit, J.-O.; Esseling, M.; Lebedev, O.I.; Moshnyaga, V.; Damaschke, B.; Van Tendeloo, G.; Samwer, K.
Title Resistive switching at manganite/manganite interfaces Type (up) A1 Journal article
Year 2011 Publication Applied physics letters Abbreviated Journal Appl Phys Lett
Volume 99 Issue 13 Pages 132512-132512,3
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract We report bipolar resistive switching between the interfaces of manganite nanocolumns. La0.7Sr0.3MnO3 films were prepared on Al2O3 substrates, where the films grow in nanocolumns from the substrate to the surface. Conductive atomic force microscopy directly detects that the resistive switching is located at the boundaries of the grains. Furthermore, mesoscopic transport measurements reveal a tunnel magnetoresistance. In combination with the resistive switching, this leads to a total of four different resistive states.
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000295618000052 Publication Date 2011-09-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-6951; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.411 Times cited 10 Open Access
Notes Approved Most recent IF: 3.411; 2011 IF: 3.844
Call Number UA @ lucian @ c:irua:91884 Serial 2881
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