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Author Xu, W.; Peeters, F.M.; Devreese, J.T.
Title The hot electron distribution of two-dimensional electrons in a polar semiconductor at zero temperature Type A3 Journal article
Year 1991 Publication Journal of physics: C: condensed matter Abbreviated Journal
Volume 3 Issue Pages 1783-1791
Keywords A3 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos A1991FE35700009 Publication Date 0000-00-00
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 1 Open Access
Notes Approved no
Call Number (up) UA @ lucian @ c:irua:948 Serial 1490
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Author Xu, Y.; Jia, D.-J.; Chen, Z.; Gao, Y.; Li, F.-S.
Title The mode-deviation effect of trapped spinor bose gas beyond mean field theory Type A1 Journal article
Year 2004 Publication International journal of modern physics: B: condensed matter physics, statistical physics, applied physics Abbreviated Journal Int J Mod Phys B
Volume 18 Issue 9 Pages 1339-1349
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract The deviation effect of spinor mode from the single-mode for a spin-1 Bose gas of trapped atoms is studied beyond the mean field theory. Based on the effective Hamiltonian with nondegenerated level of the collective spin states, the splitting level of the system energy due to the deviation effect has been calculated. For the large condensates of (87)Rb and (23)Na with atom number N > 10(5), the splitting fraction of the energy, arising from the magnetization exhibited by the trapped Bose gas, is found to have a typical order of (10(-4) similar to 10(-8)), decreasing as N(-2) for (87)Rb and increasing as -N(-2) for 23 Na, respectively.
Address
Corporate Author Thesis
Publisher Place of Publication Singapore Editor
Language Wos 000222342400008 Publication Date 2004-06-18
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0217-9792;1793-6578; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 0.736 Times cited 1 Open Access
Notes Approved Most recent IF: 0.736; 2004 IF: 0.361
Call Number (up) UA @ lucian @ c:irua:94805 Serial 2096
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Author Musolino, N.; Bals, S.; Van Tendeloo, G.; Clayton, N.; Walker, E.; Flukiger, R.
Title Investigation of (Bi,Pb)2212 crystals : observation of modulation-free phase Type A1 Journal article
Year 2004 Publication Physica: C : superconductivity Abbreviated Journal Physica C
Volume 401 Issue 1-4 Pages 270-272
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract We report the complete disappearance of the structural modulation in heavily lead-doped Bi2-xPbxSr2CaCu2O8+delta crystals observed by transmission electron microscopy. Crystals with a nominal lead content of x = 0.8, corresponding to an effective lead content of x = 0.39, yield the non-modulated phase. The superconducting properties of this modulation-free phase (beta phase) have been studied and compared to those of undoped crystals displaying the modulated phase (alpha phase). Magnetisation measurements reveal that the irreversibility field H-irr(T) and relaxation rates are strongly improved within the beta phase. Measurements of the lower critical field, H-cl, show that the anisotropy factor, E, is considerably reduced in the modulation-free crystals. This is the signature of stronger coupling between CuO2 layers which in turn deeply influences the effectiveness of the pinning. These measurements explain the enhanced pinning properties in moderately Pb-doped crystals in which the a phase and P phase coexist. The enhanced pinning is not only due to the alpha/beta interfaces, which act as effective pinning centers: the emergence of modulation-free domains, characterized by a strongly reduced anisotropy, also significantly contribute to this effect. (C) 2003 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000187852100050 Publication Date 2003-10-17
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 9 Open Access
Notes Approved Most recent IF: 1.404; 2004 IF: 1.072
Call Number (up) UA @ lucian @ c:irua:94809 Serial 1730
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Author Verberck, B.; Nikolaev, A.V.; Michel, K.H.
Title Orientational charge density waves and the metal-insulator transition in polymerized KC60 Type A1 Journal article
Year 2004 Publication AIP conference proceedings Abbreviated Journal
Volume 723 Issue Pages 339-342
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Polymerized KC60 undergoes a structural phase transition accompanied by a metal-insulator transition around 50 K. To explain the structural aspect, a mechanism involving small orientational deviations of the valence electron density on every C-60 monomer orientational charge density waves (OCDWs) – has already been proposed earlier. In the present work, we address the metal-insulator transition using the OCDW concept. We are inspired by the analogy between a polymer chain exhibiting an OCDW and a linear atomic chain undergoing a static lattice deformation doubling the unit cell: such a deformation implies a band gap at the zone boundary, yielding an insulating state (Peierls instability). Within our view, a similar mechanism occurs in polymerized KC60; the OCDW plays the role of the lattice deformation. We present tight-binding band structure calculations and conclude that the metal-insulator transition can indeed be explained using OCDWs, but that the threedimensionality of the crystal plays an unexpected key role.
Address
Corporate Author Thesis
Publisher Place of Publication New York Editor
Language Wos Publication Date 0000-00-00
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0094-243x 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:94831 Serial 2513
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Author Chen, Z.; Feng, X.; Xu, Y.; Yu, M.Y.
Title Optical bistability and multistability in four-level systems Type A1 Journal article
Year 2003 Publication Physica scripta Abbreviated Journal Phys Scripta
Volume 68 Issue 3 Pages 199-204
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract The optical behavior of a four-level system in a ring cavity driven by two coherent laser fields is studied. One laser field is treated as the incident field and the other the control field, respectively. It is found that there is optical transparency when the difference between the two frequency detunings of the incident and control fields from the corresponding atomic transition frequencies is zero. Optical bistability can be produced and controlled by increasing the magnitude of the frequency difference. The bistable hysteresis becomes larger when the frequency difference is increased. Further increase of the latter can lead to onset of multistability.
Address
Corporate Author Thesis
Publisher Place of Publication Stockholm Editor
Language Wos 000185204400005 Publication Date 2003-08-04
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-8949;1402-4896; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.28 Times cited 8 Open Access
Notes Approved Most recent IF: 1.28; 2003 IF: 0.688
Call Number (up) UA @ lucian @ c:irua:94844 Serial 2471
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Author Abakumov, A.M.; Alekseeva, A.M.; Rozova, M.G.; Antipov, E.V.; Lebedev, O.I.; Van Tendeloo, G.
Title Ordering of tetrahedral chains in the Sr2MnGaO5 brownmillerite Type A1 Journal article
Year 2003 Publication Journal of solid state chemistry Abbreviated Journal J Solid State Chem
Volume 174 Issue 2 Pages 319-328
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Tetrahedral chain ordering in the Sr2MnGaO5 structure is studied using electron diffraction (ED) and high-resolution electron microscopy. The ED patterns show the presence of satellite reflections, which indicate a commensurately modulated structure with a = 5.4056(8) Angstrom b 16.171(3) Angstrom, c = 5.5592(7) Angstrom, q – 1/2c*, superspace group Immma(00gamma,)s00. The Superstructure arises due to ordering of the two types of symmetry related tetrahedral chains (L and R) according to a ... LRLR ... sequence, where L and R chains alternate along the c-axis within the same (GaO) layer. Numerous defects at different structural levels were observed, comprising interleaving L and R chains, violation of the ... LRLR ... chain sequence within one layer, different stacking modes of the ... LRLR ... ordered layers with subsequent alternation of blocks of different width along the h-axis of the brownmillerite subcell and island fragmentation of the modulated superstructure. By in situ heating ED experiments it is found that the long-range ordering of the tetrahedral chains is stable tip to 665degreesC and is completely suppressed at 905degreesC. (C) 2003 Elsevier Inc. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000185180500011 Publication Date 2003-07-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-4596; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.299 Times cited 34 Open Access
Notes Approved Most recent IF: 2.299; 2003 IF: 1.413
Call Number (up) UA @ lucian @ c:irua:94846 Serial 2506
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Author Nikolaev, A.V.; Michel, K.H.
Title Symmetry lowering at the structural phase transitions in NpO2 and UO2 Type A1 Journal article
Year 2003 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 68 Issue 5 Pages 054112-054112,7
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The structural phase transitions with electric-quadrupole long-range order in NpO2 (Fm (3) over barm-->Pn (3) over barm) and UO2 (Fm (3) over barm-->Pa (3) over bar) are analyzed from a group theoretical point of view. In both cases, the symmetry lowering involves three quadrupolar components belonging to the irreducible representation T-2g (Gamma(5)) of O-h and condensing in a triple-q structure at the X point of the Brillouin zone. The Pa (3) over bar structure is close to Pn (3) over barm, but allows for oxygen displacements. The Pa (3) over bar ordering leads to an effective electrostatic attraction between electronic quadrupoles while the Pn (3) over barm ordering results in a repulsion between them. It is concluded that the Pn (3) over barm structure can be stabilized only through some additional process such as strengthening of the chemical bonding between Np and O. We also derive the relevant structure-factor amplitudes for Pn (3) over barm and Pa (3) over bar, and the effect of domains on resonant x-ray scattering experiments.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000185240100038 Publication Date 2003-08-29
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 15 Open Access
Notes Approved Most recent IF: 3.836; 2003 IF: NA
Call Number (up) UA @ lucian @ c:irua:94847 Serial 3405
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Author Betouras, J.J.; Ivanov, V.A.; Peeters, F.M.
Title Ginzburg-Landau theory and effects of pressure on a two-band superconductor : application to MgB2 Type A1 Journal article
Year 2003 Publication European physical journal : B : condensed matter and complex systems Abbreviated Journal Eur Phys J B
Volume 31 Issue 3 Pages 349-354
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We present a model of pressure effects of a two-band superconductor based on a Ginzburg-Landau free energy with two order parameters. The parameters of the theory are pressure as well as temperature dependent. New pressure effects emerge as a result of the competition between the two bands. The theory then is applied to MgB2. We identify two possible scenaria regarding the fate of the two Q subbands under pressure, depending on whether or not both subbands are above the Fermi energy at ambient pressure. The splitting of the two subbands is probably caused by the E-2g, distortion. If only one subband is above the Fermi energy at ambient pressure (scenario I), application of pressure diminishes the splitting and it is possible that the lower subband participates in the superconductivity. The corresponding crossover pressure and Gruneisen parameter are estimated. In the second scenario both bands start above the Fermi energy and they move below it, either by pressure or via the substitution of Mg by Al. In both scenaria, the possibility of electronical topological transition is emphasized. Experimental signatures of both scenaria are presented and existing experiments are discussed in the light of the different physical pictures.
Address
Corporate Author Thesis
Publisher Place of Publication Berlin Editor
Language Wos 000181614300008 Publication Date 2004-03-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6028;1434-6036; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.461 Times cited 10 Open Access
Notes Approved Most recent IF: 1.461; 2003 IF: 1.457
Call Number (up) UA @ lucian @ c:irua:94859 Serial 1343
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Author Horvath, Z.E.; Biro, L.P.; Van Tendeloo, G.; Tondeur, C.; Bister, G.; Pierard, N.; Fonseca, A.; Nagy, J.B.
Title Optimization of the amount of catalyst and reaction time in single wall nanotube production Type A1 Journal article
Year 2003 Publication Diffusion and defect data : solid state data : part B : solid state phenomena Abbreviated Journal Solid State Phenom
Volume 94 Issue Pages 271-274
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The influence of the amount of catalyst and the reaction time on the quantity and quality of catalytically grown single wall carbon nanotubes (SWNT) was investigated. The aim was to optimize some of the SWNT growth parameters using TEM and HRTEM. The thickness of catalyst layer influences the synthesis of the nanotube because the gas composition can differ between top and bottom. Microscopic investigation of the grown SWNT samples showed that the thicker the catalyst layer the lower relative nanotube content, so the deeper parts of the catalyst layer are less effective: The optimum time for the reaction was found to be 10 minutes. This may be understood assuming that nanotube growth needs an initial incubation time while the activity of the catalyst decreases steadily until the nariotube growth stops.
Address
Corporate Author Thesis
Publisher Place of Publication Vaduz Editor
Language Wos Publication Date 0000-00-00
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1012-0394; 1662-9779 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number (up) UA @ lucian @ c:irua:94860 Serial 2490
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Author Yandouzi, M.; Pauwels, B.; Schryvers, D.; Van Swygenhoven, H.; Van Tendeloo, G.
Title Structural characterization of nanostructured Ni3Al processed by inert gas condensation Type A1 Journal article
Year 2003 Publication Diffusion and defect data : solid state data : part A : defect and diffusion forum Abbreviated Journal
Volume 213 Issue 2 Pages 19-30
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract High-resolution transmission electron microscopy was performed on compacted Ni(3)Al nanostructured material prepared by the inert gas condensation technique. From electron diffraction data an incomplete L1(2) ordering of the crystallites is observed in the free particles as well as in the room temperature compacted samples. However, a completely ordered L1(2) structure with much bigger and well-defined crystallites exhibiting several defects is observed in material compacted and annealed at 773 K. Sharp crystallite boundaries as well as amorphous material and voids are observed in between crystallites in all samples, the former being dominant in the annealed material, the latter in the as-prepared one.
Address
Corporate Author Thesis
Publisher Place of Publication Aedermannsdorf Editor
Language Wos Publication Date 0000-00-00
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1012-0386 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:94868 Serial 3221
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Author Ivanov, V.A.; Betouras, J.J.; Peeters, F.M.
Title MgB2 : superconductivity and pressure effects Type P1 Proceeding
Year 2003 Publication Abbreviated Journal
Volume Issue Pages 35-46
Keywords P1 Proceeding; Condensed Matter Theory (CMT)
Abstract We present a Ginzburg-Landau theory for a two-band superconductor with emphasis on MgB2. We propose experiments which lead to identification of the possible scenarios: whether both sigma- and pi-bands superconduct or sigma-alone. According to the second scenario a microscopic theory of superconducting MgB2 is proposed based on the strongly interacting or-electrons and non-correlated pi-electrons of boron ions. The kinematic and Coulomb interactions of sigma-electrons provide the superconducting state with an anisotropic gap of s(*)-wave symmetry. The critical temperature T-c has a non-monotonic dependence on the distance r between the centers of gravity of sigma- and pi-bands. The position of MgB2 on a bell-shaped curve T-c (r) is identified in the overdoped region. The derived superconducting density of electronic states is in agreement with available experimental and theoretical data. It is argued that the effects of pressure are crucial to identify the microscopic origin of superconductivity in MgB2. Possibilities for increase of T, are discussed.
Address
Corporate Author Thesis
Publisher Springer Place of Publication Dordrecht Editor
Language Wos Publication Date 0000-00-00
Series Editor Series Title Abbreviated Series Title
Series Volume 106 Series Issue Edition
ISSN 1-4020-1372-8 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:94869 Serial 2020
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Author Helm, M.; Peeters, F.M.; DeRosa, F.; Colas, E.; Harbison, J.P.; Florez, L.T.
Title Far-infrared spectroscopy of minibands and confined donors in GaAs/AlxGa1-xAs superlattices Type A1 Journal article
Year 1991 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 43 Issue Pages 13983-13991
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos A1991FQ97400019 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 77 Open Access
Notes Approved no
Call Number (up) UA @ lucian @ c:irua:949 Serial 1174
Permanent link to this record
 

 
Author Verberck, B.; Nikolaev, A.V.; Michel, K.H.
Title Theoretical model for the structural phase transition at the metal-insulator transition in polymerized KC60 Type A1 Journal article
Year 2002 Publication Physical Review B Abbreviated Journal Phys Rev B
Volume 66 Issue 16 Pages 165425-165425,14
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The recently discovered structural transition in polymerized KC60 at about 50 K results in a doubling of the unit cell volume and accompanies the metal-insulator transition. Here we show that the ((a) over right arrow+(c) over right arrow,(b) over right arrow,(a) over right arrow-(c) over right arrow) superstructure results from small orientational charge density waves along the polymer chains and concomitant displacements of the surrounding K+ ions. The effect is specific for the space group Pmnn of KC60 and is absent in RbC60 and CsC60 (space group I2/m). The mechanism is relevant for the metal-insulator transition.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000179286400135 Publication Date 2002-10-30
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 10 Open Access
Notes Approved Most recent IF: 3.836; 2002 IF: NA
Call Number (up) UA @ lucian @ c:irua:94907 Serial 3608
Permanent link to this record
 

 
Author Vodolazov, D.I.; Peeters, F.M.
Title Dynamic transitions between metastable states in a superconducting ring Type A1 Journal article
Year 2002 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 66 Issue 5 Pages 054537-054537,7
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Applying the time-dependent Ginzburg-Landau equations, transitions between metastable states of a superconducting ring are investigated in the presence of an external magnetic field. It is shown that if the ring exhibits several metastable states at a particular magnetic field, the transition from one metastable state to another one is governed by both the relaxation time of the absolute value of the order parameter tau(\psi\) and the relaxation time of the phase of the order parameter tau(phi). We found that the larger the ratio tau(\psi\)/tau(phi), the closer the final state will be to the absolute minimum of the free energy, i.e., the thermodynamic equilibrium. The transition to the final state occurs through a subsequent set of single phase slips at a particular point along the ring.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000177873000143 Publication Date 2002-08-30
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 34 Open Access
Notes Approved Most recent IF: 3.836; 2002 IF: NA
Call Number (up) UA @ lucian @ c:irua:94917 Serial 768
Permanent link to this record
 

 
Author Shi, J.; Peeters, F.M.; Edmonds, K.W.; Gallagher, B.L.
Title Even-odd transition in the Shubnikov-de Haas oscillations in a two-dimensional electron gas subjected to periodic magnetic and electric modulations Type A1 Journal article
Year 2002 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 66 Issue 3 Pages 035328-035328,9
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We investigate low-temperature magnetotransport of high-mobility two-dimensional electron gases subjected to one-dimensional periodic magnetic and electric modulations. Our previous quantum perturbation theory is extended to lower temperatures and the energy broadening due to impurity scattering is incorporated. Numerical calculations are made for situations where several Landau bands overlap. We find that the Shubnikov-de Haas (SdH) oscillations are dominated by collisional resistance. The amplitudes of the SdH oscillations are strongly modulated and the positions of the SdH minima switch between even and odd Landau-level filling factors, in the resistance both parallel and perpendicular to the one-dimensional modulation. This is a consequence of the internal structure (i.e., smeared out van Hove singularities) of overlapping Landau bands. Our theoretical results are in good agreement with recent experiments.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000177338500090 Publication Date 2002-10-01
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 32 Open Access
Notes Approved Most recent IF: 3.836; 2002 IF: NA
Call Number (up) UA @ lucian @ c:irua:94918 Serial 1091
Permanent link to this record
 

 
Author Baelus, B.J.; Yampolskii, S.V.; Peeters, F.M.
Title Coupled mesoscopic superconductors : Ginzburg-Landau theory Type A1 Journal article
Year 2002 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 66 Issue 2 Pages 024517-024517,14
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The magnetic coupling between two concentric mesoscopic superconductors with nonzero thickness is studied using the nonlinear Ginzburg-Landau theory. We calculated the free energy, the expelled field, the total field profile, the Cooper-pair density, and the current density distribution. By putting a smaller superconducting disk or ring in the center of a larger ring, the properties change drastically. Extra ground-state transitions are found, where the total vorticity stays the same, but the vorticity of the inner superconductor changes by 1. Due to the magnetic coupling, the current in the external ring exhibits extra jumps at the transition fields where the vorticity of the inner superconductor changes. In this case, for certain temperatures, re-entrant behavior and switching on and off of the superconducting behavior of the rings are found as a function of the magnetic field. A H-T phase diagram is obtained for the situation where the inner ring has a higher critical temperature than the outer ring. An analytic expression for the magnetic coupling is obtained for thin rings and extreme type-II superconductors.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000177338400112 Publication Date 2002-10-01
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 11 Open Access
Notes Approved Most recent IF: 3.836; 2002 IF: NA
Call Number (up) UA @ lucian @ c:irua:94920 Serial 536
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Author Freire, J.A.K.; Freire, V.N.; Farias, G.A.; Peeters, F.M.
Title Exciton trapping in a periodically modulated magnetic field Type A1 Journal article
Year 2002 Publication Brazilian journal of physics Abbreviated Journal Braz J Phys
Volume 32 Issue 2 Pages 310-313
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The behavior of excitons in spatially modulated magnetic fields is described taking into account the exciton spin contribution. The results show that the exciton trapping in periodic magnetic fields is possible and dependent on the modulation profile.
Address
Corporate Author Thesis
Publisher Place of Publication São Paulo Editor
Language Wos 000176522000016 Publication Date 2005-04-18
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0103-9733; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 0.732 Times cited 1 Open Access
Notes Approved Most recent IF: 0.732; 2002 IF: 0.678
Call Number (up) UA @ lucian @ c:irua:94923 Serial 1120
Permanent link to this record
 

 
Author Badalyan, S.M.; Peeters, F.M.
Title Joule heat in a two-dimensional electron gas exposed to a normal non-homogeneous magnetic field of a 'chess' configuration Type A1 Journal article
Year 2002 Publication Physica: B : condensed matter Abbreviated Journal Physica B
Volume 316 Issue Pages 216-218
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We have calculated analytically the spatial distribution of the electric field and current density, and obtained the Joule heat generation rate in a two-dimensional electron gas (2DEG) subjected to a non-homogeneous magnetic field of a 'chess' configuration. The generation of the Joule heat from the 2DEG is mainly concentrated near the singular corners of each 'chess' field and tends to zero in other corners. (C) 2002 Elsevier Science B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000176297400047 Publication Date 2002-10-15
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0921-4526; ISBN Additional Links UA library record; WoS full record
Impact Factor 1.386 Times cited Open Access
Notes Approved Most recent IF: 1.386; 2002 IF: 0.609
Call Number (up) UA @ lucian @ c:irua:94925 Serial 1753
Permanent link to this record
 

 
Author Morozov, V.A.; Belik, A.A.; Stefanovich, S.Y.; Grebenev, V.V.; Lebedev, O.I.; Van Tendeloo, G.; Lazoryak, B.I.
Title High-temperature phase transition in the whitlockite-type phosphate Ca9In(PO4)7 Type A1 Journal article
Year 2002 Publication Journal of solid state chemistry Abbreviated Journal J Solid State Chem
Volume 165 Issue 2 Pages 278-288
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The double phosphate Ca9In(PO4)(7) was obtained by solid-state reaction and was studied by room and high-temperature Xray powder diffraction, electron diffraction, high-resolution electron microscopy, second-harmonic generation (SHG) technique, differential scanning calorimetry, dielectric and conductivity measurements. The beta-Ca9In(PO4)(7) room-temperature phase is related to the mineral whitlockite and is similar to beta-Ca-3(PO4)(2). It has space group R (3) over barc, with unit cell parameters: a = 10.4008(1) Angstrom, c = 37.272(1) Angstrom, Z = 6. The structure was refined by the Rietveld method (R-wp = 4.69, R-I = 1.81). A reversible first-order beta <----> beta' phase transition of the ferroelectric type with T-c = 902 K is revealed by SHG, differential scanning calorimetry and dielectric measurements. The centrosymmetric beta'-Ca9In(PO4)(7) (973 K) has space group R (3) over barc, a = 10.4611(2) Angstrom, c = 37.874 (1) Angstrom (R-wp = 4.27, R-I = 4.11). Compared to the low-temperature beta-Ca9In(PO4)(7) structure, beta'-Ca9In(PO4)(7) can be described as an orientational disordering of the P1O(4) tetrahedra together with a calcium disordering on the M3 site. (C) 2002 Elsevier Science (USA).
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000175916000010 Publication Date 2002-10-06
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-4596; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.299 Times cited 57 Open Access
Notes Approved Most recent IF: 2.299; 2002 IF: 1.671
Call Number (up) UA @ lucian @ c:irua:94926 Serial 1467
Permanent link to this record
 

 
Author Yampolskii, S.V.; Peeters, F.M.
Title Giant vortices in small mesoscopic disks : an approximate description Type A1 Journal article
Year 2002 Publication Physica: C : superconductivity Abbreviated Journal Physica C
Volume 369 Issue 1/4 Pages 347-350
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We present an approximate description of the giant vortex state in a thin mesoscopic superconducting disk within the phenomenological Ginzburg-Landau approach. Analytical asymptotic expressions for the energies of the states with fixed vorticity are obtained when a small magnetic flux is accumulated in the disk. The spectrum of the lowest Landau levels of such a disk is also discussed. (C) 2001 Elsevier Science B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000174200000063 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
Impact Factor 1.404 Times cited Open Access
Notes Approved Most recent IF: 1.404; 2002 IF: 0.912
Call Number (up) UA @ lucian @ c:irua:94930 Serial 1342
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Author Baelus, B.J.; Yampolskii, S.V.; Peeters, F.M.
Title Magnetic coupling between mesoscopic superconducting rings Type A1 Journal article
Year 2002 Publication Physica: C : superconductivity Abbreviated Journal Physica C
Volume 369 Issue 1/4 Pages 366-369
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Using the nonlinear Ginzburg-Landau theory we investigated the dependence of the magnetic coupling between two concentric mesoscopic superconducting rings on their thickness. The size of this magnetic coupling increases with the thickness of the rings. (C) 2001 Elsevier Science B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000174200000067 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 1 Open Access
Notes Approved Most recent IF: 1.404; 2002 IF: 0.912
Call Number (up) UA @ lucian @ c:irua:94931 Serial 1865
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Author Chang, K.; Xia, J.B.; Wu, H.B.; Feng, S.L.; Peeters, F.M.
Title Quantum-confined magneto-Stark effect in diluted magnetic semiconductor coupled quantum wells Type A1 Journal article
Year 2002 Publication Applied physics letters Abbreviated Journal Appl Phys Lett
Volume 80 Issue 10 Pages 1788-1790
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The magneto-Stark effect in a diluted magnetic semiconductor (DMS) coupled quantum well (CQW) induced by an in-plane magnetic field is investigate theoretically. Unlike the usual electro-Stark effects, in a DMS CQW the Lorenz force leads to a spatially separated exciton. The in-plane magnetic field can shift the ground state of the magnetoexciton from a zero in-plane center of mass (CM)/momentum to a finite CM momentum, and render the ground state of magnetoexciton stable against radiative recombination due to momentum conservation. (C) 2002 American Institute of Physics.
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000174181800036 Publication Date 2002-07-26
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 8 Open Access
Notes Approved Most recent IF: 3.411; 2002 IF: 4.207
Call Number (up) UA @ lucian @ c:irua:94932 Serial 2775
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Author Huang, W.; Zhang, X.-B.; Tu, J.; Kong, F.; Ning, Y.; Xu, J.; Van Tendeloo, G.
Title Synthesis and characterization of graphite nanofibers deposited on nickel foams Type A1 Journal article
Year 2002 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys
Volume 4 Issue 21 Pages 5325-5329
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Nickel foams were used as catalysts to dissociate acetylene and deposit carbon atoms. Graphite nanofibers with distinct structures were developed at 550degreesC with nickel foams pretreated with hydrogen. HREM observations showed that the graphite layers of the nanofibers were aligned at a certain angle to the fiber axis. It is suggested that hydrogen treatment and metal catalysts have a tremendous impact on the yields and microstructures of the graphite nanofibers. The growth mechanism of these fish-bone graphite nanofibers is also discussed.
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge Editor
Language Wos 000178635300016 Publication Date 2002-10-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1463-9076;1463-9084; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.123 Times cited 20 Open Access
Notes Approved Most recent IF: 4.123; 2002 IF: 1.838
Call Number (up) UA @ lucian @ c:irua:94938 Serial 3411
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Author Novoselov, K.S.; Geim, A.K.; Dubonos, S.V.; Cornelissens, Y.G.; Peeters, F.M.; Maan, J.C.
Title Quenching of the Hall effect in localised high magnetic field regions Type A1 Journal article
Year 2002 Publication Physica. E: Low-dimensional systems and nanostructures Abbreviated Journal Physica E
Volume 12 Issue 1/4 Pages 244-247
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We report the suppression of the Hall effect in a mesoscopic Hall cross with a strong magnetic field only in the centre and vanishingly small outside, The local magnetic field is produced by placing Dy pillar on top of a structure with a high-mobility two-dimensional electron gas. The effect is found to be due to a sharp increase of the number of back-scattered and quasi-localised electron orbits. The possibility of localising electrons inside the magnetic inhomogeneity region is discussed. (C) 2002 Elsevier Science B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher North-Holland Place of Publication Amsterdam Editor
Language Wos 000175206300061 Publication Date 2002-10-15
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1386-9477; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.221 Times cited 3 Open Access
Notes Approved Most recent IF: 2.221; 2002 IF: 1.107
Call Number (up) UA @ lucian @ c:irua:94939 Serial 2804
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Author De Gryse, O.; Clauws, P.; Vanhellemont, J.; Lebedev, O.; van Landuyt, J.; Simoen, E.; Claeys, C.
Title Chemical and structural characterization of oxide precipitates in heavily boron doped silicon by infrared spectroscopy and transmission electron microscopy Type P1 Proceeding
Year 2002 Publication Abbreviated Journal
Volume Issue Pages 183-194
Keywords P1 Proceeding; Electron microscopy for materials research (EMAT)
Abstract Infrared absorption spectra of oxygen precipitates in boron doped silicon with a boron concentration between 10(17) and 10(19) cm(-3) are analyzed, applying the spectral function theory of the composite precipitates. The aspect ratio of the platelet precipitates has been determined by transmission electron microscopy measurements. Our analysis shows that in samples with moderate doping levels (<10(18) B cm(-3)) SiOgamma precipitates are formed with stoichiometry as in the lightly doped case. In the heavily (>10(18) cm(-3)) boron doped samples, however, the measured spectra of the precipitates are consistent with a mixture of SiO2 and B2O3. with a volume fraction of B2O3 as high as 0.41 in the most heavily doped case.
Address
Corporate Author Thesis
Publisher Place of Publication S.l. Editor
Language Wos Publication Date 0000-00-00
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1-56677-344-X 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:94950 Serial 344
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Author Hens, S.; van Landuyt, J.; Bender, H.; Boullart, W.; Vanhaelemeersch, S.
Title Chemical and structural analysis of etching residue layers in semiconductor devices with energy filtering transmission electron microscopy Type A1 Journal article
Year 2001 Publication Materials science in semiconductor processing Abbreviated Journal Mat Sci Semicon Proc
Volume 4 Issue 1/3 Pages 109-111
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract The use of an energy-filtering held emission gun transmission electron microscope (CM30 FEG Ultratwin) allows, apart from imaging morphologies down to nanometer scale, the fast acquisition of high-resolution element distributions. Electrons that have lost energy corresponding to characteristic inner-shell loss edges are used to form the element maps. The production of Ultra Large-Scale Integration (ULSI) devices with dimensions below 0.25 mum requires among others the formation of a multilayer metallization scheme by means of repeatedly applying the deposition and etching of dielectrics and metals. In this work the evolution of the surface chemical species on etched Al lines in a post-etch cleaning process has been investigated by energy filtering transmission electron microscopy, with the aim to understand the role of each process step on the removal of the etching residues. (C) 2001 Elsevier Science Ltd. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Oxford Editor
Language Wos 000167727200026 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
Impact Factor 2.359 Times cited Open Access
Notes Approved Most recent IF: 2.359; 2001 IF: 0.419
Call Number (up) UA @ lucian @ c:irua:94967 Serial 343
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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
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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 Lebedev, O.I.; Turner, S.; Liu, S.; Cool, P.; Van Tendeloo, G.
Title New nano-architectures of mesoporous silica spheres analyzed by advanced electron microscopy Type A1 Journal article
Year 2012 Publication Nanoscale Abbreviated Journal Nanoscale
Volume 4 Issue 5 Pages 1722-1727
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA)
Abstract Using template-containing silica microspheres as a precursor, novel ordered mesoporous silica nanoparticles with a narrow pore size distribution and high crystallinity have been synthesized by various hydrothermal merging processes. Several architectures like chains, dumbbells, triangles, squares and flowers have been discovered. The linking mechanisms of these interacting silica spheres leading to the formation of ordered nano-structures are studied by HRTEM, HAADF-STEM and electron tomography and a plausible model is presented for several merging processes.
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge Editor
Language Wos 000300433700051 Publication Date 2011-12-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2040-3364;2040-3372; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 7.367 Times cited 5 Open Access
Notes Fwo Approved Most recent IF: 7.367; 2012 IF: 6.233
Call Number (up) UA @ lucian @ c:irua:95038 Serial 2328
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Author Ramezanipour, F.; Greedan, J.E.; Siewenie, J.; Donaberger, R.L.; Turner, S.; Botton, G.A.
Title A vacancy-disordered, oxygen-deficient perovskite with long-range magnetic ordering : local and average structures and magnetic properties of Sr2Fe1.5Cr0.5O5 Type A1 Journal article
Year 2012 Publication Inorganic chemistry Abbreviated Journal Inorg Chem
Volume 51 Issue 4 Pages 2638-2644
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The local and average crystal structures and magnetic properties of the oxygen-deficient perovskite Sr2Fe1.5Cr0.5O5+y were studied using powder X-ray and neutron diffraction, neutron-pair distribution function analysis, and electron energy-loss spectroscopy. This material crystallizes in the cubic Pm3̅m space group, with a = 3.94491(14) Å. The oxygen vacancies are distributed randomly throughout the perovskite-type structure, and the average coordination number of the Fe(Cr) sites is 5. Refinement of the neutron diffraction data indicates y 0.05. This is in discordance with an earlier report on a material with the same nominal composition and cell constant. Electron energy-loss Cr L2,3-edge spectroscopy shows that Cr3+ is present, which is also contrary to previous speculation. Neutron-pair distribution function studies show that a brownmillerite-like model involving ordered vacancies and alternating octahedral and tetrahedral coordination at the metal sites, gives a better description of the local structure out to 5 Å. A remarkable phenomenon determined by neutron diffraction in Sr2Fe1.5Cr0.5O5 is the occurrence of a long-range G-type antiferromagnetic ordering with Tc ≈ 565 K because cubic oxygen-deficient perovskites with B-site disorder usually do not undergo transitions to magnetically ordered states. The observation of long-range antiferromagnetic order and the Tc value are in accordance with previous Mössbauer spectroscopic studies.
Address
Corporate Author Thesis
Publisher Place of Publication Easton, Pa Editor
Language Wos 000300466300079 Publication Date 2012-01-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0020-1669;1520-510X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.857 Times cited 12 Open Access
Notes Fwo Approved Most recent IF: 4.857; 2012 IF: 4.593
Call Number (up) UA @ lucian @ c:irua:95039 Serial 3828
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