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Author Verberck, B.; Nikolaev, A.V.; Michel, K.H.
Title Theoretical model for the structural phase transition and the metal-insulator transition in polymerized KC60 Type A1 Journal article
Year 2004 Publication Fullerenes, nanotubes, and carbon nanostructures T2 – 6th Biennial International Workshop on Fullerenes and Atomic Clusters, JUN 30-JUL 04, 2003, St Petersburg, RUSSIA Abbreviated Journal (down) Fuller Nanotub Car N
Volume 12 Issue 1-2 Pages 243-252
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Abstract The recently discovered structural phase transition in Polymerized KC60 at about 50K leads to a doubling of the unit cell volume and is accompanied by a 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 orientational charge density waves along the polymer chains and correlated displacements of the K+ ions. The presented model can also account for the metal-insulator transition. The effect is specific for the space group Pmnn of KC60 and is absent in both Rb- and CsC60 (space group 12/m), in agreement with the present experimental knowledge of these compounds.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000220551600040 Publication Date 2004-03-15
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1536-383X;1536-4046; ISBN Additional Links UA library record; WoS full record
Impact Factor 1.35 Times cited Open Access
Notes Approved Most recent IF: 1.35; 2004 IF: 1.117
Call Number UA @ lucian @ c:irua:103259 Serial 3607
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Author Tarakina, N.V.; Verberck, B.
Title Tubular fullerenes in carbon nanotubes Type A1 Journal article
Year 2012 Publication Fullerenes, nanotubes, and carbon nanostructures Abbreviated Journal (down) Fuller Nanotub Car N
Volume 20 Issue 4-7 Pages 538-542
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Abstract We investigate the optimal orientations and positions of tubular fullerene molecules C-70, C-80 and C-90 encapsulated in single-walled carbon nanotubes (SWCNTs). We find that increasing the tube radius leads to the following succession of energetically stable regimes: 1) lying molecules positioned on the tube's long axis, 2) tilted molecules on the tube's long axis and 3) lying molecules shifted away from the tube's long axis. In the case of C-70 and C-80 molecules, standing on-axis configurations also occur. Our findings are relevant for the possible application of molecular-orientation-dependent electronic properties of fullerene nanopeapods.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000304297500045 Publication Date 2012-05-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1536-383X;1536-4046; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.35 Times cited Open Access
Notes ; This work was financially supported by the Research Foundation – Flanders (FWO-Vl). B. V. is a Postdoctoral Fellow of the Research Foundation-Flanders (FWO-Vl). ; Approved Most recent IF: 1.35; 2012 IF: 0.764
Call Number UA @ lucian @ c:irua:99004 Serial 3737
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Author Michel, K.H.; Verberck, B.; Nikolaev, A.V.
Title Nanotube field and one-dimensional fluctuations of C60 molecules in carbon nanotubes Type A1 Journal article
Year 2005 Publication European physical journal : B : condensed matter and complex systems Abbreviated Journal (down) Eur Phys J B
Volume 48 Issue 1 Pages 113-124
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Berlin Editor
Language Wos 000233998600016 Publication Date 2005-12-13
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 25 Open Access
Notes Approved Most recent IF: 1.461; 2005 IF: 1.720
Call Number UA @ lucian @ c:irua:56408 Serial 2279
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Author Verberck, B.; Tarakina, N.V.
Title Tubular fullerenes inside carbon nanotubes : optimal molecular orientation versus tube radius Type A1 Journal article
Year 2011 Publication European physical journal : B : condensed matter and complex systems Abbreviated Journal (down) Eur Phys J B
Volume 80 Issue 3 Pages 355-362
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
Abstract We present an investigation of the orientations and positions of tubular fullerene molecules (C90, ..., C200) encapsulated in single-walled carbon nanotubes (SWCNT), a series of so-called fullerene nanopeapods. We find that increasing the tube radius leads to the following succession of energetically stable regimes: (1) lying molecules positioned on the tube's long axis; (2) tilted molecules on the tube's long axis; and (3) lying molecules shifted away from the tube's long axis. As opposed to C70 and C80 molecules encapsulated in a SWCNT, standing orientations do not develop. Our results are relevant for the possible application of molecular-orientation-dependent electronic properties of fullerene nanopeapods, and also for the interpretation of future experiments on double-walled carbon nanotube formation by annealing fullerene peapod systems.
Address
Corporate Author Thesis
Publisher Place of Publication Berlin Editor
Language Wos 000289576200010 Publication Date 2011-03-14
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 ; This work was financially supported by the Research Foundation – Flanders (FWO-VI). B.V. is a Postdoctoral Fellow of the Research Foundation – Flanders (FWO-VI). ; Approved Most recent IF: 1.461; 2011 IF: 1.534
Call Number UA @ lucian @ c:irua:89286 Serial 3738
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Author Tyutyunnik, A.P.; Slobodin, B.V.; Samigullina, R.F.; Verberck, B.; Tarakina, N.V.
Title K2CaV2O7 : a pyrovanadate with a new layered type of structure in the A2BV2O7 family Type A1 Journal article
Year 2013 Publication Journal of the Chemical Society : Dalton transactions Abbreviated Journal (down) Dalton T
Volume 42 Issue 4 Pages 1057-1064
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The crystal structure of K2CaV2O7 prepared by a conventional solid-state reaction has been solved by a direct method and refined using Rietveld full profile fitting based on X-ray powder diffraction data. This compound crystallises in the triclinic space group (P (1) over bar, Z = 2) with unit cell constants a = 7.1577(1) angstrom, b = 10.5104(2) angstrom, c = 5.8187(1) angstrom, alpha = 106.3368(9)degrees, beta = 106.235(1)degrees, gamma = 71.1375(9)degrees. The structure can be described as infinite undulating CaV2O72- layers parallel to the ac plane, which consist of pairs of edge-sharing CaO6 octahedra connected to each other through V2O7 pyrogroups. The potassium atoms are positioned in two sites between the layers, with a distorted IX-fold coordination of oxygen atoms. The chemical composition obtained from the structural solution was confirmed by energy-dispersive X-ray analysis. The stability of compounds in the family of alkali metal calcium pyrovanadates is discussed based on an analysis of the correlation between anion and cation sizes and theoretical first-principles calculations.
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Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000312659200030 Publication Date 2012-10-04
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1477-9226;1477-9234; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.029 Times cited 3 Open Access
Notes ; N.V.T. acknowledges funding by the Bavarian Ministry of Sciences, Research and the Arts. B. V. was financially supported by the Flemish Science Foundation (FWO-Vlaanderen). ; Approved Most recent IF: 4.029; 2013 IF: 4.097
Call Number UA @ lucian @ c:irua:105945 Serial 3536
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Author Verberck, B.; Cambedouzou, J.; Vliegenthart, G.A.; Gompper, G.; Launois, P.
Title A Monte Carlo study of C70 molecular motion in C70@SWCNT peapods Type A1 Journal article
Year 2011 Publication Carbon Abbreviated Journal (down) Carbon
Volume 49 Issue 6 Pages 2007-2021
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We present Monte Carlo simulations of chains of C70 molecules encapsulated in a single-walled carbon nanotube (SWCNT). For various tube radii R (6.5 Å less-than-or-equals, slant R less-than-or-equals, slant 7.5 Å), we analyze rotational and translational motion of the C70 molecules, as a function of temperature. Apart from reproducing the experimentally well-established lying and standing molecular orientations for small and large tube radii, respectively, we observe, depending on the tube diameter, a variety of molecular motions, orientational flipping of lying molecules, and the migration of molecules resulting in a continual rearrangement of the C70 molecules in clusters of varying lengths. With increasing temperature, the evolution of the pair correlation functions reveals a transition from linear harmonic chain behavior to a hard-sphere liquid, making C70@SWCNT peapods tunable physical realizations of two well-known one-dimensional model systems.
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Corporate Author Thesis
Publisher Place of Publication Oxford Editor
Language Wos 000288689900025 Publication Date 2011-01-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0008-6223; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.337 Times cited 10 Open Access
Notes ; Helpful discussions with K.H. Michel, P.-A. Albouy and C. Bousige are greatly acknowledged. This work was financially supported by the Research Foundation – Flanders (FWO-Vl). B.V. is a Postdoctoral Fellow of the Research Foundation Flanders (FWO-VI). ; Approved Most recent IF: 6.337; 2011 IF: 5.378
Call Number UA @ lucian @ c:irua:89660 Serial 2201
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Author Launois, P.; Chorro, M.; Verberck, B.; Albouy, P.-A.; Rouzière, S.; Colson, D.; Forget, A.; Noé, L.; Kataura, H.; Monthioux, M.; Cambedouzou, J.
Title Transformation of C70 peapods into double walled carbon nanotubes Type A1 Journal article
Year 2010 Publication Carbon Abbreviated Journal (down) Carbon
Volume 48 Issue 1 Pages 89-98
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract X-ray diffraction studies comparing the transformation of C(60) and C(70) peapods into double walled carbon nanotubes are presented. The structures of the as-formed DWCNTs are strikingly similar, showing that they are not dependent on the nature of the fullerene precursor. High temperature X-ray diffraction measurements of C(70) peapods below the coalescence temperature show that confined C(70) molecules in large tubes undergo an orientational. transition to free rotations. Fast re-orientations of C(70) molecules allow cyclo-addition between adjacent fullerenes to form, in good agreement with the mechanism of coalescence proposed in the literature for C(60) molecules. (C) 2009 Elsevier Ltd. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Oxford Editor
Language Wos 000272018800012 Publication Date 2009-08-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0008-6223; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.337 Times cited 27 Open Access
Notes ; ; Approved Most recent IF: 6.337; 2010 IF: 4.896
Call Number UA @ lucian @ c:irua:94389 Serial 3696
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Author Michel, K.H.; Verberck, B.; Nikolaev, A.
Title Mercator maps of orientations of a C60 molecule in single-walled nanotubes with distinct radii Type A1 Journal article
Year 2005 Publication AIP conference proceedings Abbreviated Journal (down)
Volume 786 Issue Pages 69-72
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We study the confinement of a C-60 molecule encapsulated in a cylindrical nanotube as a function of the tube radius. Drawing the Mercator maps of the potential, we find two distinct molecular orientations; for tubes with small radii, R-T less than or similar to 7 angstrom, a fivefold axis of the molecule coincides with the tube long axis, for larger radii, R-T less than or similar to 8 angstrom, a threefold axis of the molecule coincides with the tube long axis. These different orientations are caused by the relative importance of the repulsive and the attractive parts of the van der Waals potentials of the molecule with the tube wall for small and large tubes respectively. Experimental evidence is provided by the apparent splitting of A(g) modes of the C-60 molecule in resonant Raman scattering.
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Corporate Author Thesis
Publisher Amer inst physics Place of Publication Melville 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 UA @ lucian @ c:irua:94738 Serial 1993
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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 (down)
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 UA @ lucian @ c:irua:94831 Serial 2513
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Author Michel, K.H.; Nikolaev, A.V.; Verberck, B.
Title Theory of crystal structures of polymerized C60-fullerite and fullerides AC60, A=K, Rb, Cs Type H1 Book chapter
Year 2001 Publication Abbreviated Journal (down)
Volume Issue Pages
Keywords H1 Book chapter; Condensed Matter Theory (CMT)
Abstract
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 462-465 Series Issue Edition
ISSN ISBN Additional Links UA library record; WoS full record;
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:36883 Serial 3614
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