Records |
Author |
Tsvyashchenko, A.V.; Nikolaev, A.V.; Velichkov, A.I.; Salamatin, A.V.; Fomicheva, L.N.; Ryasny, G.K.; Sorokin, A.A.; Kochetov, O.I.; Budzynski, M.; Michel, K.H. |
Title |
Lowering of the spatial symmetry at the gamma ->alpha phase transition in cerium |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
82 |
Issue |
9 |
Pages |
1-4 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Using time-differential perturbed angular correlation spectroscopy we have measured the electric field gradient (EFG) at 111Cd probe nuclei in solid Ce in a pressure range up to 8 GPa. Covering various allotropic phases of Ce, we find that the value of the EFG in the cubic α phase is almost four times larger than in the cubic γ phase and close to values in the noncubic phases α′ and α″. These results together with the differences in time modulation of the spectra are interpreted as evidence for quadrupolar electronic charge-density ordering and symmetry lowering at the γ→α transition while the lattice remains face-centered cubic |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000282004400001 |
Publication Date |
2010-09-16 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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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 |
11 |
Open Access |
|
Notes |
; This work is supported by the Program of the Presidium of the Russian Academy of Sciences “Physics of Strongly Compressed Matter.” We are grateful to S. M. Stishov, B. Verberck, A. N. Grum-Grzhimailo, V. B. Brudanin and G. Heger for support of this work and discussion of the results. ; |
Approved |
Most recent IF: 3.836; 2010 IF: 3.774 |
Call Number |
UA @ lucian @ c:irua:85464 |
Serial |
1854 |
Permanent link to this record |
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Author |
Verberck, B.; Heresanu, V.; Rouziere, S.; Cambedouzou, J.; Launois, P.; Kovats, E.; Pekker, S.; Vliegenthart, G.A.; Michel, K.H.; Gompper, G. |
Title |
Fullerene-cubane : X-ray scattering experiments and Monte Carlo simulations |
Type |
A1 Journal article |
Year |
2008 |
Publication |
Fullerenes, nanotubes, and carbon nanostructures
T2 – 8th Biennial International Workshop on Fullerenes and Atomic Clusters, (IWFAC 2007), JUL 02-06, 2007, St Petersburg, RUSSIA |
Abbreviated Journal |
Fuller Nanotub Car N |
Volume |
16 |
Issue |
5-6 |
Pages |
293-300 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
Abstract |
We report single-crystal X-ray diffuse scattering measurements on C-60.C8H8 fullerene-cubane showing that the C-60 molecules are orientationally disordered at 300 and 150K and get ordered at low temperatures. Monte Carlo simulations provide further insight in the orientational behavior of both C-60 and C8H8 molecules; low-temperature molecular orientations are predicted. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000259645200003 |
Publication Date |
2008-09-28 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
1536-383X;1536-4046; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.35 |
Times cited |
6 |
Open Access |
|
Notes |
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Approved |
Most recent IF: 1.35; 2008 IF: 0.680 |
Call Number |
UA @ lucian @ c:irua:102640 |
Serial |
1295 |
Permanent link to this record |
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Author |
Verberck, B.; Michel, K.H. |
Title |
Anisotropic packing of C-70 molecules in carbon nanotubes |
Type |
A1 Journal article |
Year |
2007 |
Publication |
Physica status solidi B-basic solid state physics |
Abbreviated Journal |
Phys Status Solidi B |
Volume |
244 |
Issue |
11 |
Pages |
4279-4282 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000251355800092 |
Publication Date |
2007-10-19 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
0370-1972;1521-3951; |
ISBN |
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Additional Links |
UA library record; WoS full record |
Impact Factor |
1.674 |
Times cited |
|
Open Access |
|
Notes |
|
Approved |
Most recent IF: 1.674; 2007 IF: 1.071 |
Call Number |
UA @ lucian @ c:irua:67350 |
Serial |
128 |
Permanent link to this record |
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Author |
Verberck, B.; Michel, K.H. |
Title |
Nanotube field and orientational properties of C70 molecules in carbon nanotubes |
Type |
A1 Journal article |
Year |
2007 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
75 |
Issue |
4 |
Pages |
045419,1-14 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
The orientation of a C(70) fullerene molecule encapsulated in a single-walled carbon nanotube (SWCNT) depends on the tube radius. First we confirm that chirality effects do not affect the orientation as well by comparing discrete atomistic calculations with the results of a continuous tube approximation for a variety of SWCNTs. The molecular and the tube symmetry are exploited by using symmetry-adapted rotator functions. We accurately determine the optimal molecular orientation as a function of the tube radius; for low (less than or similar to 7 A) and high (greater than or similar to 7.2 A) tube radii, lying and standing molecular orientations are recovered, respectively. In between, we observe a transition regime. In addition, we consider off-axis positions. We perform a one-dimensional liquid description of a chain of on-axis C(70) molecules inside a SWCNT. All results agree well with recent x-ray diffraction experiments. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Lancaster, Pa |
Editor |
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Language |
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Wos |
000243895600128 |
Publication Date |
2007-01-17 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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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 |
23 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.836; 2007 IF: 3.172 |
Call Number |
UA @ lucian @ c:irua:63752 |
Serial |
2280 |
Permanent link to this record |
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Author |
Verberck, B.; Michel, K.H. |
Title |
Nanotube field of C60 molecules in carbon nanotubes: atomistic versus continuous approach |
Type |
A1 Journal article |
Year |
2006 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
74 |
Issue |
4 |
Pages |
045421,1-14 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Lancaster, Pa |
Editor |
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Language |
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Wos |
000239426800113 |
Publication Date |
2006-07-22 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
31 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.836; 2006 IF: 3.107 |
Call Number |
UA @ lucian @ c:irua:60090 |
Serial |
2281 |
Permanent link to this record |
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Author |
Verberck, B.; Michel, K.H. |
Title |
Nanotube field of C60 and C70 molecules in carbon nanotubes |
Type |
A1 Journal article |
Year |
2007 |
Publication |
International journal of quantum chemistry |
Abbreviated Journal |
Int J Quantum Chem |
Volume |
107 |
Issue |
13 |
Pages |
2294-2319 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000249459800002 |
Publication Date |
2007-02-20 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0020-7608;1097-461X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.92 |
Times cited |
6 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.92; 2007 IF: 1.368 |
Call Number |
UA @ lucian @ c:irua:65785 |
Serial |
2282 |
Permanent link to this record |
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Author |
Verberck, B.; Michel, K.H.; Nikolaev, A.V. |
Title |
Crystal structures of polymerized fullerides AC60, A=K, Rb, Cs, and alkali-mediated interactions |
Type |
A1 Journal article |
Year |
2002 |
Publication |
The journal of chemical physics |
Abbreviated Journal |
J Chem Phys |
Volume |
116 |
Issue |
23 |
Pages |
10462-10474 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Starting from a model of rigid interacting C-60 polymer chains on an orthorhombic lattice, we study the mutual orientation of the chains and the stability of the crystalline structures Pmnn and I2/m. We take into account (i) van der Waals interactions and electric quadrupole interactions between C-60 monomers on different chains as well as (ii) interactions of the monomers with the surrounding alkali atoms. The direct interactions (i) always lead to an antiferrorotational structure Pmnn with alternate orientation of the C-60 chains in planes (001). The interactions (ii) with the alkalis consist of two parts: translation-rotation (TR) coupling where the orientations of the chains interact with displacements of the alkalis, and quadrupolar electronic polarizability (ep) coupling, where the electric quadrupoles on the C-60 monomers interact with induced quadrupoles due to excited electronic d-states of the alkalis. Both interactions (ii) lead to an effective orientation-orientation interaction between the C-60 chains and always favor the ferrorotational structure I2/m, where C-60 chains have a same orientation. The structures Pmnn for KC60 and I2/m for Rb- and CsC60 are the result of a competition between the direct interaction (i) and the alkali-mediated interactions (ii). In Rb- and CsC60 the latter are found to be dominant, the preponderant role being played by the quadrupolar electronic polarizability of the alkali ions. (C) 2002 American Institute of Physics. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000175905800044 |
Publication Date |
2002-07-26 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0021-9606; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.965 |
Times cited |
12 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.965; 2002 IF: 2.998 |
Call Number |
UA @ lucian @ c:irua:103350 |
Serial |
578 |
Permanent link to this record |
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Author |
Verberck, B.; Michel, K.H.; Nikolaev, A.V. |
Title |
The C60 molecules in (C60)N@SWCNT peapods: crystal field, intermolecular interactions and dynamics |
Type |
A1 Journal article |
Year |
2006 |
Publication |
Fullerenes, nanotubes, and carbon nanostructures |
Abbreviated Journal |
Fuller Nanotub Car N |
Volume |
14 |
Issue |
2/3 |
Pages |
171-178 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000238762900006 |
Publication Date |
2006-06-08 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
1536-383X;1536-4046; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.35 |
Times cited |
10 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 1.35; 2006 IF: 0.462 |
Call Number |
UA @ lucian @ c:irua:60025 |
Serial |
3518 |
Permanent link to this record |
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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 |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
New York |
Editor |
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Language |
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Wos |
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Publication Date |
0000-00-00 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0094-243x |
ISBN |
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Additional Links |
UA library record; WoS full record; |
Impact Factor |
|
Times cited |
|
Open Access |
|
Notes |
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Approved |
Most recent IF: NA |
Call Number |
UA @ lucian @ c:irua:94831 |
Serial |
2513 |
Permanent link to this record |
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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 |
2005 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
71 |
Issue |
16 |
Pages |
165117-11 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
A theoretical model is presented for the description of the metal-insulator transition which accompanies the structural phase transition at T approximate to 50 K in polymerized KC60. The model involves orientational charge density waves (along the C-60 polymer chains) which were introduced previously for a description of the structural phase transition. A satisfactory qualitative and quantitative understanding is obtained when the three-dimensionality of the crystal and the presence of the K+ counterions is properly taken into account. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000228763100035 |
Publication Date |
2005-04-27 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
1 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.836; 2005 IF: 3.185 |
Call Number |
UA @ lucian @ c:irua:104076 |
Serial |
2514 |
Permanent link to this record |
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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 |
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 |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000220551600040 |
Publication Date |
2004-03-15 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1536-383X;1536-4046; |
ISBN |
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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 |
Permanent link to this record |
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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 |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000179286400135 |
Publication Date |
2002-10-30 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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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 |
UA @ lucian @ c:irua:94907 |
Serial |
3608 |
Permanent link to this record |
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Author |
Zieliński, P.; Michel, K.H. |
Title |
Microscopic model of surfaces in orientationally disordered ionic crystals : the (001) surface of KCN |
Type |
A1 Journal article |
Year |
1992 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
46 |
Issue |
8 |
Pages |
4806-4815 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
The crystallographic structure and the distribution of orientations of molecular ions are studied near the surface in an orientationally disordered crystal with the use of a Green-function formalism. The orientational degrees of freedom are treated by means of symmetry-adapted functions of angular coordinates. The structure of the (001) surface of KCN in its cubic fcc phase is then predicted using the existing data on the interaction of the ions K+ and CN-. A local antiferroelectric and antiferroelastic order i shown to exist in the surface region. The magnitude of the order and the spatial extent of the ordered re ion increase as the temperature approaches the point of the phase transition to the ordered phase. The,influence of the external electric field on the structure of the surface is predicted. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Lancaster, Pa |
Editor |
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Language |
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Wos |
A1992JK72500049 |
Publication Date |
2002-07-27 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0163-1829;1095-3795; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.736 |
Times cited |
4 |
Open Access |
|
Notes |
|
Approved |
PHYSICS, CONDENSED MATTER 16/67 Q1 # |
Call Number |
UA @ lucian @ c:irua:2974 |
Serial |
2029 |
Permanent link to this record |