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Author Stuer, C.; van Landuyt, J.; Bender, H.; Rooyackers, R.; Badenes, G.
  Title The use of convergent beam electron diffraction for stress measurements in shallow trench isolation structures Type A1 Journal article
  Year 2001 Publication Materials science in semiconductor processing Abbreviated Journal Mat Sci Semicon Proc
  Volume 4 Issue 1/3 Pages 117-119
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
  Abstract Shallow trench isolation (STI) is a promising technology for the isolation structures of the new generation of ULSI devices with dimensions below 0.18 mum. The various processing steps cause stress fields in STI structures, which can lead to defect formation in the silicon substrate. In their turn, stress fields affect the electrical parameters and the reliability of devices. Convergent beam electron diffraction (CBED) is used in this study to examine the influence of a wet and a dry pre-gate oxidation on the stress distribution around STI structures. The measurements are performed on STI structures with different width and spacing. CBED analysis is compared with bright-field TEM images. Defects are observed in high-strain areas of small isolated structures. (C) 2001 Elsevier Science Ltd. All rights reserved.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Oxford Editor
  Language Wos 000167727200028 Publication Date 2002-10-14
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1369-8001; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 2.359 Times cited 6 Open Access
  Notes Approved Most recent IF: 2.359; 2001 IF: 0.419
  Call Number (up) UA @ lucian @ c:irua:94968 Serial 3602
Permanent link to this record
 

 
Author Lu, Y.-G.; Verbeeck, J.; Turner, S.; Hardy, A.; Janssens, S.D.; De Dobbelaere, C.; Wagner, P.; Van Bael, M.K.; Van Tendeloo, G.
  Title Analytical TEM study of CVD diamond growth on TiO2 sol-gel layers Type A1 Journal article
  Year 2012 Publication Diamond and related materials Abbreviated Journal Diam Relat Mater
  Volume 23 Issue Pages 93-99
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract The early growth stages of chemical vapor deposition (CVD) diamond on a solgel TiO2 film with buried ultra dispersed diamond seeds (UDD) have been studied. In order to investigate the diamond growth mechanism and understand the role of the TiO2 layer in the growth process, high resolution transmission electron microscopy (HRTEM), energy-filtered TEM and electron energy loss spectroscopy (EELS) techniques were applied to cross sectional diamond film samples. We find evidence for the formation of TiC crystallites inside the TiO2 layer at different diamond growth stages. However, there is no evidence that diamond nucleation starts from these crystallites. Carbon diffusion into the TiO2 layer and the chemical bonding state of carbon (sp2/sp3) were both extensively investigated. We provide evidence that carbon diffuses through the TiO2 layer and that the diamond seeds partially convert to amorphous carbon during growth. This carbon diffusion and diamond to amorphous carbon conversion make the seed areas below the TiO2 layer grow and bend the TiO2 layer upwards to form the nucleation center of the diamond film. In some of the protuberances a core of diamond seed remains, covered by amorphous carbon. It is however unlikely that the remaining seeds are still active during the growth process.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Amsterdam Editor
  Language Wos 000302887600017 Publication Date 2012-01-26
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0925-9635; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 2.561 Times cited 16 Open Access
  Notes Iap; Esteem 026019; Fwo Approved Most recent IF: 2.561; 2012 IF: 1.709
  Call Number (up) UA @ lucian @ c:irua:95037UA @ admin @ c:irua:95037 Serial 111
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Author Bourgeois, J.; Hervieu, M.; Poienar, M.; Abakumov, A.M.; Elkaïm, E.; Sougrati, M.T.; Porcher, F.; Damay, F.; Rouquette, J.; Van Tendeloo, G.; Maignan, A.; Haines, J.; Martin, C.;
  Title Evidence of oxygen-dependent modulation in LuFe2O4 Type A1 Journal article
  Year 2012 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 85 Issue 6 Pages 064102-064120,10
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract A polycrystalline sample of LuFe2O4 has been investigated by means of powder synchrotron x-ray and neutron diffraction and transmission electron microscopy (TEM), along with Mössbauer spectroscopy and transport and magnetic properties. A monoclinic distortion is unambiguously evidenced, and the crystal structure is refined in the monoclinic C2/m space group [aM = 5.9563(1) Å, bM = 3.4372(1) Å, cM = 8.6431(1) Å, β = 103.24(1)°]. Along with the previously reported modulations distinctive of the charge-ordering (CO) of the iron species, a new type of incommensurate order is observed, characterized by a vector q⃗1 = α1a⃗M* + γ1c⃗M* (with α1 ≅ 0.55, γ1 ≅ 0.13). In situ heating TEM observations from 300 to 773 K confirm that the satellites associated with q⃗1 vanish completely, only at a temperature significantly higher than the CO temperature. This incommensurate modulation has a displacive character and corresponds primarily to a transverse displacive modulation wave of the Lu cations position, as revealed by the high resolution, high angle annular dark field scanning TEM images and in agreement with synchrotron data refinements. Analyses of vacuum-annealed samples converge toward the hypothesis of a new ordering mechanism, associated with a tiny oxygen deviation from the O4 stoichiometry.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000299896900003 Publication Date 2012-02-06
  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 24 Open Access
  Notes Hercules Approved Most recent IF: 3.836; 2012 IF: 3.767
  Call Number (up) UA @ lucian @ c:irua:95042 Serial 1095
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Author Armelao, L.; Bertagnolli, H.; Bleiner, D.; Groenewolt, M.; Gross, S.; Krishnan, V.; Sada, C.; Schubert, U.; Tondello, E.; Zattin, A.
  Title Highly dispersed mixed zirconia and hafnia nanoparticles in a silica matrix: First example of a ZrO2-HfO2-SiO2 ternary oxide system Type A1 Journal article
  Year 2007 Publication Advanced functional materials Abbreviated Journal Adv Funct Mater
  Volume Issue Pages
  Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
  Abstract ZrO2 and HfO2 nanoparticles are homogeneously dispersed in SiO2 matrices (supported film and bulk powders) by copolymerization of two oxozirconium and oxohafnium clusters (M4O(2)(OMc)(12), M= Zr, Hf; OMc = OC(O)-C(CH3)=CH2) with (methacryloxypropyl)trimethoxysilane (MAPTMS, (CH2=C(CH3)C(O)O)-(CH2)(3)Si(OCH3)(3)). After calcination (at a temperature >= 800 degrees C), a silica matrix with homogeneously distributed MO2 nanocrystallites is obtained. This route yields a spatially homogeneous dispersion of the metal precursors inside the silica matrix, which is maintained during calcination. The composition of the films and the powders is studied before and after calcination by using Fourier transform infrared (FTIR) analysis, X-ray photoelectron spectroscopy (XPS), secondary ion mass spectrometry (SIMS), and laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS). The local environment of the metal atoms in one of the calcined samples is investigated by using X-ray Absorption Fine Structure (XAFS) spectroscopy. Through X-ray diffraction (XRD) the crystallization of Hf and Zr oxides is seen at temperatures higher than those expected for the pure oxides, and transmission electron microscopy (TEM) shows the presence of well-distributed and isolated crystalline oxide nanoparticles (540 nm).
  Address
  Corporate Author Thesis
  Publisher Place of Publication Weinheim Editor
  Language Wos 000248062100011 Publication Date 2007-05-29
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1616-301x ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 12.124 Times cited 34 Open Access
  Notes Approved Most recent IF: 12.124; 2007 IF: 7.496
  Call Number (up) UA @ lucian @ c:irua:95083 Serial 4521
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Author Wang, X.F.; Vasilopoulos, P.; Peeters, F.M.
  Title Spin-current modulation and square-wave transmission through periodically stubbed electron waveguides Type A1 Journal article
  Year 2002 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 65 Issue 16 Pages 165217
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract Ballistic spin transport through waveguides, with symmetric or asymmetric double stubs attached to them periodically, is studied systematically in the presence of a weak spin-orbit coupling that makes the electrons precess. By an appropriate choice of the waveguide length and of the stub parameters injected spin-polarized electrons can be blocked completely and the transmission shows a periodic and nearly-square-type behavior, with values 1 and 0, with wide gaps when only one mode is allowed to propagate in the waveguide. A similar behavior is possible for a certain range of the stub parameters even when two modes can propagate in the waveguide and the conductance is doubled. Such a structure is a good candidate for establishing a realistic spin transistor. A further modulation of the spin current can be achieved by inserting defects in a finite-number stub superlattice. Finite-temperature effects on the spin conductance are also considered.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Lancaster, Pa Editor
  Language Wos 000175325000061 Publication Date 2002-07-27
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0163-1829;1095-3795; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 3.836 Times cited 112 Open Access
  Notes Approved Most recent IF: 3.836; 2002 IF: NA
  Call Number (up) UA @ lucian @ c:irua:95128 Serial 3082
Permanent link to this record
 

 
Author Hai; Studart; Peeters, F.M.
  Title Electron-mobility in 2 coupled delta-layers Type A1 Journal article
  Year 1995 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 52 Issue 15 Pages 11273-11276
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract The low-temperature transport properties are studied for electrons confined in delta-doped semiconductor structures with two sheets in parallel. The subband quantum mobility and transport mobility are calculated numerically for the Si delta-doped GaAs systems. The effect of coupling of the two delta layers on the electron transport is investigated. Our calculations are in good agreement with experimental results.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Lancaster, Pa Editor
  Language Wos A1995TA85200092 Publication Date 2002-07-27
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0163-1829;1095-3795; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 3.736 Times cited 25 Open Access
  Notes Approved no
  Call Number (up) UA @ lucian @ c:irua:95343 Serial 976
Permanent link to this record
 

 
Author Hai; Studart; Peeters, F.M.
  Title Multisubband electron-transport in delta-doped semiconductor systems Type A1 Journal article
  Year 1995 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 52 Issue 11 Pages 8363-8371
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract The electron transport properties in delta-doped semiconductor systems-are studied. The subband electronic structure of the delta-doped system is obtained by solving the coupled Schrodinger and Poisson equations. The screening of the quasi-two-dimensional electron gas is taken into account for the ionized impurity scattering through the matrix dielectric function within the random-phase approximation. The quantum and transport mobilities are calculated numerically as a function of the total electron density and the width of the doped layer at zero temperature. The intersubband scattering and the effect of empty subbands above the Fermi level on the electron mobilities are investigated. The calculated mobilities are in reasonable agreement with the available experimental results.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Lancaster, Pa Editor
  Language Wos A1995RV81800091 Publication Date 2002-07-27
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0163-1829;1095-3795; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 3.736 Times cited 67 Open Access
  Notes Approved no
  Call Number (up) UA @ lucian @ c:irua:95353 Serial 2243
Permanent link to this record
 

 
Author Peeters, F.M.; Golub, J.E.
  Title Binding energy of the barbell exciton Type A1 Journal article
  Year 1991 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 43 Issue Pages 5159-5162
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract
  Address
  Corporate Author Thesis
  Publisher Place of Publication Lancaster, Pa Editor
  Language Wos A1991EY62300076 Publication Date 0000-00-00
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1098-0121; 0163-1829 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 3.736 Times cited 27 Open Access
  Notes Approved no
  Call Number (up) UA @ lucian @ c:irua:955 Serial 239
Permanent link to this record
 

 
Author Yang, T.; Perkisas, T.; Hadermann, J.; Croft, M.; Ignatov, A.; Van Tendeloo, G.; Greenblatt, M.
  Title Synthesis and structure determination of ferromagnetic semiconductors LaAMnSnO6(A = Sr, Ba) Type A1 Journal article
  Year 2011 Publication Journal of materials chemistry Abbreviated Journal J Mater Chem
  Volume 21 Issue 1 Pages 199-205
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract LaAMnSnO(6) (A = Sr, Ba) have been synthesized by high temperature solid-state reactions under dynamic 1% H(2)/Ar flow. Rietveld refinements on room temperature powder X-ray diffraction data indicate that LaSrMnSnO(6) crystallizes in the GdFeO(3)-structure, with space group Pnma and, combined with transmission electron microscopy, LaBaMnSnO(6) in Imma. Both space groups are common in disordered double-perovskites. The Mn(3+) and Sn(4+) ions whose valence states were confirmed by X-ray absorption spectroscopy, are completely disordered over the B-sites and the BO(6) octahedra are slightly distorted. LaAMnSnO(6) are ferromagnetic semiconductors with a T(C) = 83 K for the Sr- and 66 K for the Ba-compound. The title compounds, together with the previously reported LaCaMnSnO(6) provide an interesting example of progression from Pnma to Imma as the tolerance factor increases. An analysis of the relationship between space group and tolerance factor for the series LaAMnMO(6) (A = Ca, Sr, Ba; M = Sn, Ru) provides a better understanding of the symmetry determination for double perovskites.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Cambridge Editor
  Language Wos 000285067300025 Publication Date 2010-10-26
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0959-9428;1364-5501; 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 (up) UA @ lucian @ c:irua:95527 Serial 3440
Permanent link to this record
 

 
Author Esken, D.; Turner, S.; Lebedev, O.I.; Van Tendeloo, G.; Fischer, R.A.
  Title Au@ZIFs: stabilization and encapsulation of cavity-size matching gold clusters inside functionalized Zeolite Imidazolate Frameworks, ZIFs Type A1 Journal article
  Year 2010 Publication Chemistry of materials Abbreviated Journal Chem Mater
  Volume 22 Issue 23 Pages 6393-6401
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract The selective formation and stabilization of very small, naked metal particles inside the cavities of metal organic frameworks (MOFs) and the simultaneous realization of an even distribution of the particles throughout the crystalline MOF host matrix over a wide range of metal loading are challenging goals. MOFs reveal high specific surface areas, tunable pore sizes, and organic linkers, which are able to interact with guests. The chemically very robust zeolite imidazolate frameworks (ZIFs) are a subclass of MOFs. We chose the microporous sodalite-like ZIF-8 (Zn(MelM)(2); IM = imidazolate) and ZIF-90 (Zn(ICA)(2); ICA = imidazolate-2-carboxyaldehyde) as host matrices to influence the dispersion of imbedded gold nanoparticles (Au NPs). The metal loading was achieved via gas phase infiltration of [Au(CO)Cl] followed by a thermal hydrogenation step to form the Au NPs. Low-dose high-resolution transmission electron microscopy ((HR)TEM) and electron tomography reveal a homogeneous distribution of Au NPs throughout the ZIF matrix. The functional groups of ZIF-90 direct the anchoring of intermediate Au species and stabilize drastically smaller and quite monodisperse Au NPs in contrast to the parent not functionalized ZIF-8. The particles can be very small, match the cavity size and approach defined molecular clusters of magic numbers, i.e., Au(55), independently from the level of loading. Post-synthetic oxidation of the aldehyde groups to yield alkyl esters by the adjacent, catalytically active metal NPs is presented as a new concept of encapsulating nanoparticles inside MOFs and allows multiple steps of metal loadings without decomposition of the MOF.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Washington, D.C. Editor
  Language Wos 000284975100025 Publication Date 2010-11-12
  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 194 Open Access
  Notes Esteem 026019 Approved Most recent IF: 9.466; 2010 IF: 6.400
  Call Number (up) UA @ lucian @ c:irua:95530 Serial 208
Permanent link to this record
 

 
Author Chaves, A.; Covaci, L.; Rakhimov, K.Y.; Farias, G.A.; Peeters, F.M.
  Title Wave-packet dynamics and valley filter in strained graphene Type A1 Journal article
  Year 2010 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 82 Issue 20 Pages 205430
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract The time evolution of a wave packet in strained graphene is studied within the tight-binding model and continuum model. The effect of an external magnetic field, as well as a strain-induced pseudomagnetic field, on the wave-packet trajectories and zitterbewegung are analyzed. Combining the effects of strain with those of an external magnetic field produces an effective magnetic field which is large in one of the Dirac cones, but can be practically zero in the other. We construct an efficient valley filter, where for a propagating incoming wave packet consisting of momenta around the K and K' Dirac points, the outgoing wave packet exhibits momenta in only one of these Dirac points while the components of the packet that belong to the other Dirac point are reflected due to the Lorentz force. We also found that the zitterbewegung is permanent in time in the presence of either external or strain-induced magnetic fields, but when both the external and strain-induced magnetic fields are present, the zitterbewegung is transient in one of the Dirac cones, whereas in the other cone the wave packet exhibits permanent spatial oscillations.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000284401600007 Publication Date 2010-11-19
  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 95 Open Access
  Notes ; This work was financially supported by CNPq under NanoBioEstruturas Contract No. 555183/2005-0, PRONEX/CNPq/FUNCAP, CAPES, the Bilateral program between Flanders and Brazil, the Belgian Science Policy (IAP), and the Flemish Science Foundation (FWO-V1) ; Approved Most recent IF: 3.836; 2010 IF: 3.774
  Call Number (up) UA @ lucian @ c:irua:95542 Serial 3905
Permanent link to this record
 

 
Author Yang, C.H.; Peeters, F.M.; Xu, W.
  Title Density of states and magneto-optical conductivity of graphene in a perpendicular 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 20 Pages 205428
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract The density of states (DOS) and the optical conductivity of graphene is calculated in the presence of a perpendicular magnetic field and where scattering on charged and short-range impurities is included. The standard Kubo formula is employed where the self-energy induced by impurity scattering and the Green's function are calculated self-consistently including inter-Landau level (LL) coupling and screening effects. It is found that the scattering from those two types of impurities results in a symmetric LL broadening and asymmetric inter-LL coupling renormalizes the LL positions to lower energy. The peak position and intensity of the magneto-optical conductivity depends on the filling factor and the broadened DOS. Good agreement is found with recent cyclotron resonance measurements.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000284400700003 Publication Date 2010-11-18
  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 39 Open Access
  Notes ; This work was supported by the National Natural Science Foundation of China under Grant No. 10804053, the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), and the Chinese Academy of Sciences and Department of Science and Technology of Yunnan Province. ; Approved Most recent IF: 3.836; 2010 IF: 3.774
  Call Number (up) UA @ lucian @ c:irua:95543 Serial 641
Permanent link to this record
 

 
Author Efimov, K.; Xu, Q.; Feldhoff, A.
  Title Transmission electron microscopy study of BA0.5Sr0.5CO0.8Fe0.2O3-\delta Perovskite decomposition at intermediate temperatures Type A1 Journal article
  Year 2010 Publication Chemistry of materials Abbreviated Journal Chem Mater
  Volume 22 Issue 21 Pages 5866-5875
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract The cubic perovskite Ba(0.5)Sr(0.5)Co(0.8)Fe(0.2)O(3-delta) (denoted BSCF) is the state-of-the-art ceramic membrane material used for oxygen separation technologies above 1150 K. BSCF is a mixed oxygen-ion and electron conductor (MIEC) and exhibits one of the highest oxygen permeabilities reported so far for dense oxides. Additionally, it has excellent phase stability above 1150 K. In the intermediate temperature range (750-1100 K), however, BSCF suffers from a slow decomposition of the cubic perovskite into variants with hexagonal stacking that are barriers to oxygen transport. To elucidate details of the decomposition process, both sintered BSCF ceramic and powder were annealed for 180-240 h in ambient air at temperatures below 1123 K and analyzed by different transmission electron microscopy techniques. Aside from hexagonal perovskite Ba(0.5)Sr(0.5)CoO(3-delta) , the formation of lamellar noncubic phases was observed in the quenched samples. The structure of the lamellae with the previously unknown composition Ba(1-x)Sr(x)Co(2-y)Fe(y)O(5-delta) was found to be related to the 15R hexagonal perovskite polytype. The valence and spin-state transition of cobalt leading to a considerable diminution of its ionic radius can be considered a reason for BSCF's inherent phase instability at intermediate temperatures.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Washington, D.C. Editor
  Language Wos 000283623700010 Publication Date 2010-10-13
  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 117 Open Access
  Notes Esteem 026019 Approved Most recent IF: 9.466; 2010 IF: 6.400
  Call Number (up) UA @ lucian @ c:irua:95546 Serial 3720
Permanent link to this record
 

 
Author Cortes-Gil, R.; Parker, D.R.; Pitcher, M.J.; Hadermann, J.; Clarke, S.J.
  Title Indifference of superconductivity and magnetism to size-mismatched cations in the layered iron arsenides Ba1-xNaxFe2As2 Type A1 Journal article
  Year 2010 Publication Chemistry of materials Abbreviated Journal Chem Mater
  Volume 22 Issue 14 Pages 4304-4311
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract The evolution of the structure, magnetic ordering, and superconductivity in the series Ba(1-x)Na(x)Fe(2)As(2) is reported up to the limiting Na-rich composition with x = 0.6; the more Na-rich compositions are unstable at high temperatures with respect to competing phases. The magnetic and superconducting behaviors of the Bai,Na,Fe,As, members are similar to those of the betterinvestigated Ba(1-x)Na(x)Fe(2)As(2) analogues. This is evidently a consequence of the quantitatively similar evolution of the structure of the FeAs layers in the two series. In Ba(1-x)Na(x)Fe(2)As(2) antiferromagnetic order and an associated structural distortion are evident for x <= 0.35 and superconductivity is evident when x exceeds 0.2. For 0.4 <= x <= 0.6 bulk superconductivity is evident, and the long-range antiferromagnetically ordered state is completely suppressed. The maximum T(c) in the Ba(1-x)Na(x)Fe(2)As(2) series, as judged by the onset of diamagnetism, is 34K in Ba(0.6)Na(0.4)Fe(2)As(2). Despite the large mis-match in sizes between the two electropositive cations which separate the FeAs layers, there is no evidence for ordering of these cations on the length scale probed by electron diffraction.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Washington, D.C. Editor
  Language Wos 000280005300027 Publication Date 2010-07-02
  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 31 Open Access
  Notes Approved Most recent IF: 9.466; 2010 IF: 6.400
  Call Number (up) UA @ lucian @ c:irua:95594 Serial 1601
Permanent link to this record
 

 
Author Chen, Y.; Shanenko, A.A.; Peeters, F.M.
  Title Hollow nanocylinder: multisubband superconductivity induced by quantum confinement Type A1 Journal article
  Year 2010 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 81 Issue 13 Pages 134523-134523:11
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract Quantization of the transverse electron motion in high-quality superconducting metallic nanowires and nanofilms results in the formation of well-distinguished single-electron subbands. They shift in energy with changing thickness, which is known to cause quantum-size superconducting oscillations. The formation of multiple subbands results in a multigap structure induced by the interplay between quantum confinement and Andreev mechanism. We investigate multisubband superconductivity in a hollow nanocylinder by numerically solving the Bogoliubov-de Gennes equations. When changing the inner radius and thickness of the hollow nanocylinder, we find a crossover from an irregular pattern of quantum-size superconducting oscillations, typical of nanowires, to an almost regular regime, specific for superconducting nanofilms. At this crossover the multigap structure becomes degenerate. The ratio of the critical temperature to the energy gap increases and approaches its bulk value while being reduced by 20-30% due to Andreev-type states driven by quantum confinement in the irregular regime.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Lancaster, Pa Editor
  Language Wos 000277207900098 Publication Date 2010-04-26
  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 21 Open Access
  Notes ; This work was supported by the Flemish Science Foundation (FWO-VI), the Interuniversity Attraction Poles Programme, Belgian States, Belgian Science Policy (IAP) and the ESF-AQDJJ network. ; Approved Most recent IF: 3.836; 2010 IF: 3.774
  Call Number (up) UA @ lucian @ c:irua:95623 Serial 1481
Permanent link to this record
 

 
Author Nistor, L.; Bender, H.; van Landuyt, J.; Nemeth, S.; Boeve, H.; De Boeck, J.; Borghs, G.
  Title HREM investigation of a Fe/GaN/Fe tunnel junction Type A1 Journal article
  Year 2001 Publication Institute of physics conference series T2 – Royal-Microscopical-Society Conference on Microscopy of Semiconducting, Materials, MAR 25-29, 2001, Univ of Oxford, Oxford, England Abbreviated Journal
  Volume Issue 169 Pages 53-56
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract The structure of Fe/GaN/Fe ferromagnetic electrodes is studied by high resolution transmission electron microscopy. The layers grow epitaxially on the GaAs substrate with the top Fe layer 90degrees rotated compared to the bottom one. The interfaces are quite rough. There is an indication of the possible occurrence of Fe3GaAs formation on the GaAs interface.
  Address
  Corporate Author Thesis
  Publisher IOP Publishing Place of Publication Bristol Editor
  Language Wos Publication Date 0000-00-00
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0-7503-0818-4 ISBN Additional Links UA library record; WoS full record;
  Impact Factor Times cited Open Access
  Notes Approved Most recent IF: NA
  Call Number (up) UA @ lucian @ c:irua:95715 Serial 1503
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Author Lebedev, O.I.; Van Tendeloo, G.; Amelinckx, S.; Leibold, B.; Habermeier, H.U.; Phillipp, F.
  Title Structure and magnetotransport properties of La2/3Ca1/3MnO3 thin films prepared by pulsed laser deposition Type P1 Proceeding
  Year 1998 Publication Materials Research Society symposium proceedings T2 – Symposium on Advances in Laser Ablation of Materials at the 1998 MRS, Spring Meeting, April 13-16, 1998, San Francisco, Calif. Abbreviated Journal
  Volume Issue Pages 219-224
  Keywords P1 Proceeding; Electron microscopy for materials research (EMAT)
  Abstract La1-xCaxMnO3-delta (LCMO) thin films are grown by pulsed laser deposition on a (100) SrTiO3 substrate at temperatures between 530 degrees C and 890 degrees C. The magnetotransport properties show a high negative magnetoresistance and a shift of the maximum of the R(T) curve as function of temperature. The Curie temperature changes with deposition temperature and film quality in the range of 100-220K. The film quality is characterised by X-ray diffraction and transmission electron microscopy (TEM); film and target compositions were verified by atomic emission spectroscopy. The local structure of the film depends on the growth conditions and substrate temperature. TEM reveals a slight distortion of the film leading to a breakdown of the symmetry from orthorhombic to monoclinic. At the highest growth temperatures, a well defined interface is observed within the LCMO film, parallel to the substrate surface; this interface divides the film into two lamellae with a different microstructure. The lamella close to the substrate is perfectly coherent with the substrate, suggesting that it is strained as a result of the lattice parameter mismatch; the upper lamella shows a typical domain structure with unusual translation interfaces characterised by a displacement vector of the type 1/2[010](m) and 1/2[001](m) when referred ten the monoclinic lattice.
  Address
  Corporate Author Thesis
  Publisher Materials research society Place of Publication Warrendale Editor
  Language Wos 000077696000032 Publication Date 2011-04-05
  Series Editor Series Title Abbreviated Series Title
  Series Volume 526 Series Issue Edition
  ISSN 1946-4274; ISBN Additional Links UA library record; WoS full record
  Impact Factor Times cited Open Access
  Notes Approved Most recent IF: NA
  Call Number (up) UA @ lucian @ c:irua:95838 Serial 3283
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Author Antipov, E.V.; Putilin, S.N.; Shpanchenko, R.V.; Alyoshin, V.A.; Rozova, M.G.; Abakumov, A.M.; Mikhailova, D.A.; Balagurov, A.M.; Lebedev, O.; Van Tendeloo, G.
  Title Structural features, oxygen and fluorine doping in Cu-based superconductors Type A1 Journal article
  Year 1997 Publication Physica: C : superconductivity T2 – International Conference on Materials and Mechanisms of, Superconductivity – High Temperature Superconductors V, Feb. 28-Mar. 04, 1997, Beijing, Peoples R. China Abbreviated Journal Physica C
  Volume 282 Issue Part 1 Pages 61-64
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract The variation of structures and superconducting properties by changing extra oxygen or fluorine atoms concentration in Hg-based Cu mixed oxides and YBa2Cu3O6+delta was studied. The data obtained by NPD study of Hg-1201 can be considered as an evidence of the conventional oxygen doping mechanism with 2 delta holes per (CuO2) layer. The extra oxygen atom was found to be located in the middle of the Hg mesh only. Different formal charges of oxygen and fluorine inserted into reduced 123 structure results in its distinct variations. The fluorine incorporation into strongly reduced YBa2Cu3O6+delta causes a significant structural rearrangement and the formation of a new compound with a composition close to YBa2Cu3O6F2 (tetragonal alpha = 3.87 Angstrom and c approximate to 13 Angstrom), which structure was deduced from the combined results of X-ray diffraction, electron diffraction and high resolution electron microscopy. Fluorination treatment by XeF2 of nonsuperconducting 123 samples causes an appearance of bulk superconductivity with T-c up to 94K.
  Address
  Corporate Author Thesis
  Publisher Elsevier Science Place of Publication Amsterdam Editor
  Language Wos A1997XZ90400019 Publication Date 2002-07-25
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0921-4534; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 1.404 Times cited 10 Open Access
  Notes Approved Most recent IF: 1.404; 1997 IF: 2.199
  Call Number (up) UA @ lucian @ c:irua:95866 Serial 3237
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Author Blank, D.H.A.; Rijnders, A.J.H.M.; Verhoeven, M.A.J.; Bergs, R.M.H.; Rogalla, H.; Verbist, K.; Lebedev, O.; Van Tendeloo, G.
  Title Characterisation of multilayer ramp-type REBa2Cu3O7-\delta structures by scanning probe microscopy and high-resolution electron microscopy Type A1 Journal article
  Year 1997 Publication Journal of alloys and compounds T2 – Symposium on High Temperature Superconductor Thin Films, Growth, Mechanisms, Interfaces, Multilayers, at the 1996 Spring Meeting of the European-Materials-Society, June 04-07, 1996, Strasbourg, France Abbreviated Journal J Alloy Compd
  Volume 251 Issue 1-2 Pages 206-208
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
  Abstract We studied the morphology of ramps in REBa2CU3O7 (REBCO) epitaxial films on SrTiO3 substrates, fabricated by RF magnetron sputter deposition and pulsed laser deposition (PLD), by scanning probe microscopy (SPM) and high resolution electron microscopy (HREM). The ramps were fabricated by Ar ion beam etching using masks of standard photoresist and TIN. AFM-studies on ramps in sputter deposited films show a strong dependence, i.e. formation of facets and ridges, on the angle of incidence of the ion beam with respect to the substrate surface as well as the rotation angle with respect to the crystal axes of the substrate. Ramps in pulsed laser deposited films did not show this dependence, Furthermore, we studied the effect of an anneal step prior to the deposition of barrier layers (i.e. PrBa2CU3O7, SrTiO3, CeO2) on the ramp. First results show a recrystallization of the ramp surface, resulting in terraces and a non-homogeneous growth of the barrier material on top of it. The thickness variations, for thin layers of barrier material, con even become much larger than expected from the amount of deposited material and are dependent on the deposition and anneal conditions. HREM studies show a well defined interface between barrier layer and electrodes. The angle of the ramp depends on the etch rate of the mask and REBCO, and on the angle of incidence of the ion beam. TiN has a much lower etch rate compared to photoresist, resulting in an angle of the ramp comparable to the angle of incidence, resulting in a low etching rate on the ramp. These results will lead to improved electrical characteristics of ramp-type junctions.
  Address
  Corporate Author Thesis
  Publisher Elsevier Science Place of Publication Lausanne Editor
  Language Wos A1997XM34000046 Publication Date 2002-07-25
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0925-8388; ISBN Additional Links UA library record; WoS full record
  Impact Factor 3.133 Times cited Open Access
  Notes Approved Most recent IF: 3.133; 1997 IF: 1.035
  Call Number (up) UA @ lucian @ c:irua:95868 Serial 310
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Author Frangis, N.; van Landuyt, J.; Grimaldi, M.G.; Calcagno, L.
  Title Electron microscopy and Rutherford backscattering spectrometry characterisation of 6H SiC samples implanted with He+ Type A1 Journal article
  Year 1996 Publication Nuclear instruments and methods in physics research: B: beam interactions with materials and atoms T2 – Symposium 1 on New Trends in Ion Beam Processing of Materials, at the, E-MRS 96 Spring Meeting, June 04-07, 1996, Strasbourg, France Abbreviated Journal Nucl Instrum Meth B
  Volume 120 Issue 1-4 Pages 186-189
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
  Abstract 6H SiC single crystals were implanted al room temperature with 1 MeV He+ up to a fluence of 2 x 10(17) at./cm(2) RBS-channeling analysis with a 2 MeV He+ beam indicated the formation of extended defects or the generation of point defects at a constant concentration over a depth of about 1 mu m. Electron microscopy characterisation revealed the presence of two amorphous buried layers at depths of about 1,75 and 4.8 mu m. They an due to the implantation and to the analysing RES beam, respectively, No extended planar or linear faults were found in the region between the surface and the first amorphous layer. However, at the surface, a 50 nm thick amorphous layer was observed in which crystalline inclusions were embedded. Electron diffraction and HREM data of the inclusions were typical for diamond, These inclusions were even found in the crystalline SiC material below this layer, however at a reduced density.
  Address
  Corporate Author Thesis
  Publisher Elsevier Place of Publication Amsterdam Editor
  Language Wos A1996VZ24500040 Publication Date 2002-07-26
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0168-583X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 1.124 Times cited 2 Open Access
  Notes Approved no
  Call Number (up) UA @ lucian @ c:irua:95882 Serial 947
Permanent link to this record
 

 
Author Frangis, N.; Nejim, A.; Hemment, P.L.F.; Stoemenos, J.; van Landuyt, J.
  Title Ion beam synthesis of \beta-SiC at 950 degrees C and structural characterization Type A1 Journal article
  Year 1996 Publication Nuclear instruments and methods in physics research: B: beam interactions with materials and atoms T2 – Symposium J on Correlated Effects in Atomic and Cluster Ion Bombardment and Implantation/Symposium C on Pushing the Limits of Ion Beam, Processing – Fr Abbreviated Journal Nucl Instrum Meth B
  Volume 112 Issue 1-4 Pages 325-329
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
  Abstract The structure of beta-SiC formed by carbon implantation into Si at high temperatures (850-950 degrees C) at doses ranging between 0.2 X 10(18) to 1 X 10(18) cm(-2) at 200 keV, was studied by combined cross section and high resolution transmission electron microscopy (XTEM and HRTEM). Implantation was performed on (001) and (111) Si wafers. In both cases a buried beta-SiC layer was formed having the same orientation as the Si matrix.
  Address
  Corporate Author Thesis
  Publisher Elsevier science bv Place of Publication Amsterdam Editor
  Language Wos A1996UW20100069 Publication Date 2002-07-26
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0168-583X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 1.124 Times cited 9 Open Access
  Notes Approved no
  Call Number (up) UA @ lucian @ c:irua:95886 Serial 1742
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Author Vanhellemont, J.; Romano Rodriguez, A.; Fedina, L.; van Landuyt, J.; Aseev, A.
  Title Point defect reactions in silicon studied in situ by high flux electron irradiation in high voltage transmission electron microscope Type A1 Journal article
  Year 1995 Publication Materials science and technology Abbreviated Journal Mater Sci Tech-Lond
  Volume 11 Issue 11 Pages 1194-1202
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
  Abstract Results are presented of in situ studies of 1 MeV electron irradiation induced (113) defect generation in silicon containing different types and concentrations of extrinsic point defects. A semiquantitative model is developed describing the influence of interfaces and stress fields and of extrinsic point defects on the (113) defect generation in silicon during irradiation. The theoretical results obtained are correlated with experimental data obtained on silicon uniformly doped with boron and phosphorus and with observations obtained by irradiating cross-sectional samples of wafers with highly doped surface layers. It is shown that in situ irradiation in a high voltage election microscope is a powerful tool for studying local point defect reactions in silicon. (C) 1995 The Institute of Materials.
  Address
  Corporate Author Thesis
  Publisher Inst Materials Place of Publication London Editor
  Language Wos A1995TQ95100016 Publication Date 2014-01-09
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0267-0836;1743-2847; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 0.995 Times cited 7 Open Access
  Notes Approved no
  Call Number (up) UA @ lucian @ c:irua:95911 Serial 2654
Permanent link to this record
 

 
Author Van Tendeloo, G.; Amelinckx, S.
  Title Electron-microscopy and the structural studies of superconducting materials and fullerites Type P1 Proceeding
  Year 1994 Publication NATO Advanced Study Institutes series: series E : applied sciences T2 – NATO Advanced Study Institute on Materials and crystallographic Aspects, of HT(c)-Superconductivity, May 17-30, 1993, Erice, Italy Abbreviated Journal
  Volume Issue Pages 521-538
  Keywords P1 Proceeding; Electron microscopy for materials research (EMAT)
  Abstract
  Address
  Corporate Author Thesis
  Publisher Kluwer Academic Place of Publication Dordrecht Editor
  Language Wos A1994BA54N00025 Publication Date 0000-00-00
  Series Editor Series Title Abbreviated Series Title
  Series Volume 263 Series Issue Edition
  ISSN 0-7923-2773-X ISBN Additional Links UA library record; WoS full record;
  Impact Factor Times cited Open Access
  Notes Approved no
  Call Number (up) UA @ lucian @ c:irua:95934 Serial 949
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Author Latimer, M.L.; Berdiyorov, G.R.; Xiao, Z.L.; Kwok, W.K.; Peeters, F.M.
  Title Vortex interaction enhanced saturation number and caging effect in a superconducting film with a honeycomb array of nanoscale holes Type A1 Journal article
  Year 2012 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 85 Issue 1 Pages 012505-012505,4
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract The electrical transport properties of a MoGe thin film with a honeycomb array of nanoscale holes are investigated. The critical current of the system shows nonmatching anomalies as a function of applied magnetic field, enabling us to distinguish between multiquanta vortices trapped in the holes and interstitial vortices located between the holes. The number of vortices trapped in each hole is found to be larger than the saturation number predicted for an isolated hole and shows a nonlinear field dependence, leading to the caging effect as predicted from the Ginzburg-Landau (GL) theory. Our experimental results are supplemented by numerical simulations based on the GL theory.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000299867200001 Publication Date 2012-01-26
  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 41 Open Access
  Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Belgian Science Policy (IAP) (theory) and by the US Department of Energy (DOE) Grant No. DE-FG02-06ER46334 (experiment). G. R. B. acknowledges an individual grant from FWO-Vl. W. K. K. acknowledges support from DOE BES under Contract No. DE-AC02-06CH11357, which also funds Argonne's Center for Nanoscale Materials (CNM), where the focused-ion-beam milling was performed. M.L.L was a recipient of the NIU/ANL Distinguished Graduate Fellowship. ; Approved Most recent IF: 3.836; 2012 IF: 3.767
  Call Number (up) UA @ lucian @ c:irua:96224 Serial 3866
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Author Ustarroz, J.; Ke, X.; Hubin, A.; Bals, S.; Terryn, H.
  Title New insights into the early stages of nanoparticle electrodeposition Type A1 Journal article
  Year 2012 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
  Volume 116 Issue 3 Pages 2322-2329
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract Electrodeposition is an increasingly important method to synthesize supported nanoparticles, yet the early stages of electrochemical nanoparticle formation are not perfectly understood. In this paper, the early stages of silver nanoparticle electrodeposition on carbon substrates have been studied by aberration-corrected TEM, using carbon-coated TEM grids as electrochemical electrodes. In this manner we have access to as-deposited nanoparticle size distribution and structural characterization at the atomic scale combined with electrochemical measurements, which represents a breakthrough in a full understanding of the nanoparticle electrodeposition mechanisms. Whereas classical models, based upon characterization at the nanoscale, assume that electrochemical growth is only driven by direct attachment, the results reported hereafter indicate that early nanoparticle growth is mostly driven by nanocluster surface movement and aggregation. Hence, we conclude that electrochemical nulceation and growth models should be revised and that an electrochemical aggregative growth mechanism should be considered in the early stages of nanoparticle electrodeposition.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Washington, D.C. Editor
  Language Wos 000299584400037 Publication Date 2011-12-23
  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 104 Open Access
  Notes Fwo Approved Most recent IF: 4.536; 2012 IF: 4.814
  Call Number (up) UA @ lucian @ c:irua:96225 Serial 2316
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Author Vagov, A.V.; Shanenko, A.A.; Milošević, M.V.; Axt, V.M.; Peeters, F.M.
  Title Extended Ginzburg-Landau formalism : systematic expansion in small deviation from the critical temperature Type A1 Journal article
  Year 2012 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 85 Issue 1 Pages 014502-014502,17
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract Based on the Gor'kov formalism for a clean s-wave superconductor, we develop an extended version of the single-band Ginzburg-Landau (GL) theory by means of a systematic expansion in the deviation from the critical temperature T(c), i.e., tau = 1 – T/T(c). We calculate different contributions to the order parameter and the magnetic field: the leading contributions (proportional to tau(1/2) in the order parameter and. t in the magnetic field) are controlled by the standard GL theory, while the next-to-leading terms (proportional to tau(3/2) in the gap and proportional to tau(2) in the magnetic field) constitute the extended GL (EGL) approach. We derive the free-energy functional for the extended formalism and the corresponding expression for the current density. To illustrate the usefulness of our formalism, we calculate, in a semianalytical form, the temperature-dependent correction to the GL parameter at which the surface energy becomes zero, and analytically, the temperature dependence of the thermodynamic critical field. We demonstrate that the EGL formalism is not just a mathematical extension to the theory: variations of both the gap and the thermodynamic critical field with temperature calculated within the EGL theory are found in very good agreement with the full BCS results down to low temperatures, which dramatically improves the applicability of the formalism compared to its standard predecessor.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000298985100002 Publication Date 2012-01-10
  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 36 Open Access
  Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Belgian Science Policy (IAP). A. V. V. is grateful to V. Zalipaev for important comments. A. A. S. thanks W. Pogosov for helpful notes. Discussions with E. H. Brandt and A. Perali are appreciated. ; Approved Most recent IF: 3.836; 2012 IF: 3.767
  Call Number (up) UA @ lucian @ c:irua:96232 Serial 1155
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Author Rønnow, T.F.; Pedersen, T.G.; Partoens, B.
  Title Biexciton binding energy in fractional dimensional semiconductors Type A1 Journal article
  Year 2012 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 85 Issue 4 Pages 045412-045412,7
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract Biexcitons in fractional dimensional spaces are studied using variational quantum Monte Carlo. We investigate the biexciton binding energy as a function of the electron-hole mass fraction sigma as well as study the dimensional dependence of biexcitons for sigma = 0 and sigma = 1. As our first application of this model we treat the H(2) molecule in two and three dimensions. Next we investigate biexcitons in carbon nanotubes within the fractional dimensional model. To this end we find a relation between the nanotube radius and the effective dimension. The results of both applications are compared with results obtained using different models and we find a reasonable agreement. Within the fractional dimensional model we find that the biexciton binding energy in carbon nanotubes accurately scales as E(B)(r,epsilon) = 1280 meV angstrom/(r epsilon), as a function of radius r and the dielectric screening epsilon.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000298922200008 Publication Date 2012-01-06
  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 21 Open Access
  Notes ; ; Approved Most recent IF: 3.836; 2012 IF: 3.767
  Call Number (up) UA @ lucian @ c:irua:96234 Serial 231
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Author Vodolazov, D.Y.; Peeters, F.M.
  Title Enhancement of the retrapping current of superconducting microbridges of finite length Type A1 Journal article
  Year 2012 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 85 Issue 2 Pages 024508-024508,6
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract We theoretically find that the resistance of a superconducting microbridge or nanowire decreases while the retrapping current I(r) for the transition to the superconducting state increases when one suppresses the magnitude of the order parameter vertical bar Delta vertical bar in the attached superconducting leads. This effect is a consequence of the increased energy interval for diffusion of the “hot” nonequilibrium quasiparticles (induced by the oscillations of vertical bar Delta vertical bar in the center of the microbridge) to the leads. The effect is absent in short microbridges (with length less than the coherence length) and it is relatively weak in long microbridges (with length larger than the inelastic relaxation length of the nonequilibrium distribution function). A nonmonotonous dependence of I(r) on the length of the microbridge is predicted. Our results are important for the explanation of the enhancement of the critical current and the appearance of negative magnetoresistance observed in many recent experiments on superconducting microbridges or nanowires.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000298863400005 Publication Date 2012-01-06
  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” and the Flemish Science Foundation (FWO-Vl). ; Approved Most recent IF: 3.836; 2012 IF: 3.767
  Call Number (up) UA @ lucian @ c:irua:96235 Serial 1065
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Author Peeters, F.M.; Smondyrev, M.A.
  Title Exact and approximate results for the polaron in one dimension Type A1 Journal article
  Year 1991 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 43 Issue Pages 4920-4924
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract
  Address
  Corporate Author Thesis
  Publisher Place of Publication Lancaster, Pa Editor
  Language Wos A1991EY62300044 Publication Date 0000-00-00
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1098-0121; 0163-1829 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 3.736 Times cited 16 Open Access
  Notes Approved no
  Call Number (up) UA @ lucian @ c:irua:963 Serial 1104
Permanent link to this record
 

 
Author Ribbens, S.; Beyers, E.; Schellens, K.; Mertens, M.; Ke, X.; Bals, S.; Van Tendeloo, G.; Meynen, V.; Cool, P.
  Title Systematic evaluation of thermal and mechanical stability of different commercial and synthetic photocatalysts in relation to their photocatalytic activity Type A1 Journal article
  Year 2012 Publication Microporous and mesoporous materials: zeolites, clays, carbons and related materials Abbreviated Journal Micropor Mesopor Mat
  Volume 156 Issue Pages 62-72
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA)
  Abstract The effect of thermal treatment and mechanical stress on the structural and photocatalytic properties of eight different (synthetic and commercial) photocatalysts has been thoroughly investigated. Different mesoporous Ti-based materials were prepared via surfactant based synthesis routes (e.g. Pluronic 123, CTMABr = Cetyltrimethylammonium bromide) or via template-free synthesis routes (e.g. trititanate nanotubes). Also, the stabilizing effect of the NaOH/NH4OH post-treatment on the templated mesoporous materials and their photocatalytic activity was investigated. Furthermore, the thermal and mechanical properties of commercially available titanium dioxides such as P25 Evonik® and Millenium PC500® were studied. The various photocatalysts were analyzed with N2-sorption, X-ray diffraction (XRD), high resolution transmission electron microscopy (HR-TEM), differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) to obtain information concerning the specific surface area, pore volume, crystal structure, morphology, phase transitions, etc. In general, results show that the NaOH post-treatment leads to an increased control of the crystallization process during calcination resulting in a higher thermal stability, but at the same time diminishes the photocatalytic activity. Mesoporous materials in which pre-synthesized nanoparticles are used as titania source have the best mechanical stability whereas the mechanical stability of the nanotubes is the most limited. At increased temperatures and pressures, the tested commercial titanium dioxides lose their superior photocatalytic activity caused by a decreased accessibility of the active sites. The observed changes in adsorption capacities and photocatalytic activities cannot be assigned to one single phenomenon. In this respect, it shows the need to define a general/standard method to compare different photocatalysts. Furthermore, it is shown that the photocatalytic properties do not necessarily deteriorate under thermal stress, but can be improved due to crystallization, even though the initial material is (partially) destroyed. It is shown that the usefulness of a specific type of photocatalyst strongly depends on the application and the temperature/pressure to which it needs to resist.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Amsterdam Editor
  Language Wos 000303625200010 Publication Date 2012-02-08
  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 8 Open Access
  Notes Fwo Approved Most recent IF: 3.615; 2012 IF: 3.365
  Call Number (up) UA @ lucian @ c:irua:96910 Serial 3466
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