Records |
Author |
Mattauch, S.; Heger, G.; Michel, K.H. |
Title |
High resolution neutron and X-ray diffraction studies as a function of temperature and electric field of the ferroelectric phase transition of RDP |
Type |
A1 Journal article |
Year |
2004 |
Publication |
Crystal research and technology |
Abbreviated Journal |
Cryst Res Technol |
Volume |
39 |
Issue |
12 |
Pages |
1027-1054 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Neutron and high resolution X-ray diffraction investigations on perfect single crystals of RbH2PO4 (RDP), a hydrogen bonded ferroelectric of KDP type are reported. The results of crystal structure analysis from diffraction data, below and above the paraelectric – ferroelectric phase transition, support a disorder – order character Of [PO4H2](-)-groups. The tetragonal symmetry of the paraelectric phase with the double well potential of the hydrogen atoms obtained by diffraction, results simply from a time-space average of orthorhombic symmetry. According to the group – subgroup relation between the tetragonal space group 142d and the orthorhombic Fdd2 a short range order of ferroelectric clusters in the tetragonal phase is observed. With decreasing temperature the ferroelectric clusters increase and the long range interaction between their local polarisation vectors leads to the formation of lamellar ferroelectric domains with alternating polarisation directions at T-C = 147 K. From the high resolution X-ray data it is concluded that below T-C the ferroelastic strain in the (a,b)-plane leads to micro-angle grain boundaries at the domain walls. The tilt angle is enhanced by an applied electric field parallel to the ferroelectric axis. The resulting dislocations at the domain walls persist in the paraelectric phase leading to a memory effect for the arrangement of twin lamellae. With increased electric field the phase transition temperature T-C is decreased. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
Berlin |
Editor |
|
Language |
|
Wos |
000225681100001 |
Publication Date |
2004-11-12 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0232-1300;1521-4079; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1 |
Times cited |
12 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 1; 2004 IF: 0.770 |
Call Number |
UA @ lucian @ c:irua:94785 |
Serial |
1459 |
Permanent link to this record |
|
|
|
Author |
Lamoen, D.; Michel, K.H. |
Title |
Crystal field, orientational order, and lattice contraction in solid C60 |
Type |
A1 Journal article |
Year |
1994 |
Publication |
The journal of chemical physics |
Abbreviated Journal |
J Chem Phys |
Volume |
101 |
Issue |
|
Pages |
1435-1443 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
A model of the intermolecular potential in solid C-60, which is based on Born-Mayer repulsions, van der Waals attractions, and electrostatic multipoles, is presented. The potential is expanded in terms of multipolar rotator functions. The orientation-orientation interaction and the crystal field are calculated. The orientational phase transition to the Pa3 phase is studied with the methods of statistical mechanics. The discontinuity of the order parameter at the transition and the temperature evolution of the order parameter are calculated. The lattice contraction at the phase transition is evaluated. The influence of the lattice contraction on the crystal field and on the orientational order is studied. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
|
Language |
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Wos |
A1994NW97900058 |
Publication Date |
2002-07-26 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0021-9606; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.952 |
Times cited |
39 |
Open Access |
|
Notes |
|
Approved |
CHEMISTRY, PHYSICAL 54/144 Q2 # PHYSICS, ATOMIC, MOLECULAR & CHEMICAL 9/35 Q2 # |
Call Number |
UA @ lucian @ c:irua:9361 |
Serial |
554 |
Permanent link to this record |
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|
|
Author |
Pelloquin, D.; Hadermann, J.; Giot, M.; Caignaert, V.; Michel, C.; Hervieu, M.; Raveau, B. |
Title |
Novel, oxygen-deficient n=3 RP-member Sr3NdFe3O9-\delta and its topotactic derivatives |
Type |
A1 Journal article |
Year |
2004 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
Volume |
16 |
Issue |
|
Pages |
1715-1724 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
|
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
Language |
|
Wos |
000221345000019 |
Publication Date |
2004-04-27 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0897-4756;1520-5002; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
9.466 |
Times cited |
24 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 9.466; 2004 IF: 4.103 |
Call Number |
UA @ lucian @ c:irua:47318 |
Serial |
2381 |
Permanent link to this record |
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|
|
Author |
Hervieu, M.; Michel, C.; Martin, C.; Huvé, M.; Van Tendeloo, G.; Maignan, A.; Pelloquin, D.; Goutenoire, F.; Raveau, B. |
Title |
Mécanismes de la non-stoechiométrie dans les nouveaux supraconducteurs à haute Tc |
Type |
A1 Journal article |
Year |
1994 |
Publication |
Journal de physique: 3: applied physics, materials science, fluids, plasma and instrumentation |
Abbreviated Journal |
|
Volume |
4 |
Issue |
|
Pages |
2057-2067 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
|
Address |
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Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
Les Ulis |
Editor |
|
Language |
|
Wos |
A1994PT17900002 |
Publication Date |
0000-00-00 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1155-4320 |
ISBN |
|
Additional Links |
UA library record; WoS full record; |
Impact Factor |
|
Times cited |
|
Open Access |
|
Notes |
|
Approved |
no |
Call Number |
UA @ lucian @ c:irua:10041 |
Serial |
1973 |
Permanent link to this record |
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|
|
Author |
Bussmann-Holder, A.; Michel, K.H. |
Title |
Bond geometry and phase transition mechanism of H-bonded ferroelectricity |
Type |
A1 Journal article |
Year |
1998 |
Publication |
Physical review letters |
Abbreviated Journal |
Phys Rev Lett |
Volume |
80 |
Issue |
|
Pages |
2173-2176 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
|
Address |
|
Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
|
Language |
|
Wos |
000072385400037 |
Publication Date |
2002-07-27 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0031-9007;1079-7114; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
8.462 |
Times cited |
81 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 8.462; 1998 IF: 6.017 |
Call Number |
UA @ lucian @ c:irua:23987 |
Serial |
246 |
Permanent link to this record |
|
|
|
Author |
Michel, K.H.; Verberck, B. |
Title |
Theory of the elastic constants of graphite and graphene |
Type |
A1 Journal article |
Year |
2008 |
Publication |
Physica status solidi: B: basic research |
Abbreviated Journal |
Phys Status Solidi B |
Volume |
245 |
Issue |
10 |
Pages |
2177-2180 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Born's long wave method is used to study the elastic properties of graphite and graphene. Starting from an empirical force constant model derived from full inplane phonon dispersions of graphite [Mohr et al., Phys. Rev. B 76, 035439 (2007)] we calculate the tension coefficients of graphene. Extending the model by interplanar interactions, we calculate the elastic constants of graphite. The agreement of our theoretical values with inelastic x-ray scattering results on elastic constants of graphite [Bosak et al., Phys. Rev. B 75, 153408 (2007)] is very satisfactory. |
Address |
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Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
Berlin |
Editor |
|
Language |
|
Wos |
000260581800066 |
Publication Date |
2008-08-25 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0370-1972; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.674 |
Times cited |
47 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 1.674; 2008 IF: 1.166 |
Call Number |
UA @ lucian @ c:irua:75660 |
Serial |
3621 |
Permanent link to this record |
|
|
|
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 |
|
Address |
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Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
|
Language |
|
Wos |
000249459800002 |
Publication Date |
2007-02-20 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
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 |
|
|
|
Author |
Michel, K.H.; Neek-Amal, M.; Peeters, F.M. |
Title |
Static flexural modes and piezoelectricity in 2D and layered crystals |
Type |
A1 Journal article |
Year |
2016 |
Publication |
Physica status solidi: B: basic research |
Abbreviated Journal |
Phys Status Solidi B |
Volume |
253 |
Issue |
253 |
Pages |
2311-2315 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Piezo- and flexoelectricity are manifestations of electromechanical coupling in solids with potential applications in nanoscale materials. Naumov etal. [Phys. Rev. Lett. 102, 217601 (2009)] have shown by first principles calculations that a monolayer BN sheet becomes macroscopically polarized in-plane when in a corrugated state. Here, we investigate the interplay of layer corrugation and in-plane polarization by atomistic lattice dynamics. We treat the coupling between static flexural modes and in-plane atomic ion displacements as an anharmonic effect, similar to the membrane effect that is at the origin of negative thermal expansion in layered crystals. We have derived analytical expressions for the corrugation-induced static in-plane strains and the optical displacements with the resulting polarization response functions. Beyond h-BN, the theory applies to transition metal dichalcogenides and dioxides. Numerical calculations show that the effects are considerably stronger for 2D h-BN than for 2H-MoS2. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
Berlin |
Editor |
|
Language |
|
Wos |
000390339000002 |
Publication Date |
2016-10-21 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0370-1972 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.674 |
Times cited |
5 |
Open Access |
|
Notes |
; The authors acknowledge useful discussions with L. Wirtz, A. Molina-Sanchez, and C. Sevik. This work was supported by the ESF-Eurographene project CONGRAN, and the Flemish Science Foundation (FWO-Vl). ; |
Approved |
Most recent IF: 1.674 |
Call Number |
UA @ lucian @ c:irua:140309 |
Serial |
4462 |
Permanent link to this record |
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|
|
Author |
Hadermann, J.; Pérez, O.; Créon, N.; Michel, C.; Hervieu, M. |
Title |
The (3 + 2)D structure of oxygen deficient LaSrCuO3.52 |
Type |
A1 Journal article |
Year |
2007 |
Publication |
Journal of materials chemistry |
Abbreviated Journal |
J Mater Chem |
Volume |
17 |
Issue |
22 |
Pages |
2344-2350 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
|
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Cambridge |
Editor |
|
Language |
|
Wos |
000247349400020 |
Publication Date |
2007-04-18 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0959-9428;1364-5501; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
|
Times cited |
7 |
Open Access |
|
Notes |
Supergmr:Hprn-Ct-2000-0021 |
Approved |
Most recent IF: NA |
Call Number |
UA @ lucian @ c:irua:64749 c:irua:64749 |
Serial |
13 |
Permanent link to this record |
|
|
|
Author |
Michel, K.H.; Costamagna; Peeters, F.M. |
Title |
Theory of thermal expansion in 2D crystals |
Type |
A1 Journal article |
Year |
2015 |
Publication |
Physica status solidi: B: basic research |
Abbreviated Journal |
Phys Status Solidi B |
Volume |
252 |
Issue |
252 |
Pages |
2433-2437 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
The thermal expansion alpha(T) in layered crystals is of fundamental and technological interest. As suggested by I. M. Lifshitz in 1952, in thin solid films (crystalline membranes) a negative contribution to alpha(T) is due to anharmonic couplings between in-plane stretching modes and out-of-plane bending (flexural modes). Genuine in-plane anharmonicities give a positive contribution to alpha(T). The competition between these two effects can lead to a change of sign (crossover) from a negative value of alpha(T) in a temperature (T) range T <= T-alpha to a positive value of alpha(T) for T > T-alpha in layered crystals. Here, we present an analytical lattice dynamical theory of these phenomena for a two-dimensional (2D) hexagonal crystal. We start from a Hamiltonian that comprises anharmonic terms of third and fourth order in the lattice displacements. The in-plane and out-of-plane contributions to the thermal expansion are studied as functions of T for crystals of different sizes. Besides, renormalization of the flexural mode frequencies plays a crucial role in determining the crossover temperature T-alpha. Numerical examples are given for graphene where the anharmonic couplings are determined from experiments. The theory is applicable to other layer crystals wherever the anharmonic couplings are known. (C) 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim |
Address |
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Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
Berlin |
Editor |
|
Language |
|
Wos |
000364690400014 |
Publication Date |
2015-08-06 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0370-1972 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.674 |
Times cited |
21 |
Open Access |
|
Notes |
; We thank B. Verberck, D. Lamoen, and A. Dobry for useful comments. We acknowledge funding from the FWO (Belgium)-MINCyT (Argentina) collaborative research project. This work is supported by the Euro GRAPHENE project CONGRAN. ; |
Approved |
Most recent IF: 1.674; 2015 IF: 1.489 |
Call Number |
UA @ lucian @ c:irua:130281 |
Serial |
4264 |
Permanent link to this record |
|
|
|
Author |
Michel, K.H.; Verberck, B. |
Title |
Rigid-plane phonons in layered crystals |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Physica status solidi: B: basic research |
Abbreviated Journal |
Phys Status Solidi B |
Volume |
249 |
Issue |
12 |
Pages |
2604-2607 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
The determination of the layer number ${\cal N}$ in nanoscale thin layered crystals is a challenging problem of technological relevance. In addition to innovative experimental techniques, a thorough knowledge of the underlying lattice dynamics is required. Starting from phenomenological atomic interaction potentials we have carried out an analytical study of the low-frequency optical phonon dispersions in layered crystals. At the gamma point of the two-dimensional Brillouin zone the optical phonon frequencies correspond to rigid-plane shearing and compression modes. We have investigated graphene multilayers (GML) and hexagonal boron-nitride multilayers (BNML). The frequencies show a characteristic dependence on ${\cal N}$. The results which are represented in the form of fan diagrams are very similar for both materials. Due to charge neutrality within layers Coulomb forces play no role, only van der Waals forces between nearest neighbor layers are relevant. The theoretical results agree with recent low-frequency Raman results on rigid-layer modes [Tan et al., Nature Mater. 11, 294 (2012)] in GML and double-resonant Raman scattering data on rigid-layer compression modes [Herziger et al., Phys. Rev. B 85, 235447 (2012)] in GML. (C) 2012 WILEY-VCH Verlag GmbH Co. KGaA, Weinheim |
Address |
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Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
Berlin |
Editor |
|
Language |
|
Wos |
000312215300072 |
Publication Date |
2012-11-19 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0370-1972; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.674 |
Times cited |
1 |
Open Access |
|
Notes |
; This work has been supported by the Flemish Science Foundation (FWO-Vl) and the Bijzonder Onderzoeksfonds, Universiteit Antwerpen (BOF-UA). ; |
Approved |
Most recent IF: 1.674; 2012 IF: 1.489 |
Call Number |
UA @ lucian @ c:irua:105992 |
Serial |
2907 |
Permanent link to this record |
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|
|
Author |
Michel, K.H.; Verberck, B. |
Title |
Theory of phonon dispersions and piezoelectricity in multilayers of hexagonal boron-nitride |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Physica status solidi: B: basic research |
Abbreviated Journal |
Phys Status Solidi B |
Volume |
248 |
Issue |
11 |
Pages |
2720-2723 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Taking into account covalent, Coulomb and van der Waals interactions, we construct the dynamical matrix and calculate the phonon dispersion relations for multilayer crystals of hexagonal boron-nitride. Coulomb interactions account for a strong overbending of optical phonons. Applying and extending Born's long-wave theory to the case of multilayer crystals, we calculate the piezoelectric stress constant equation image as a function of the number of layers equation image. In agreement with group theory, we find that equation image for equation image even; for an uneven number equation image of layers we obtain equation image, i.e. the piezoelectric constant decreases as equation image. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Berlin |
Editor |
|
Language |
|
Wos |
000297517100069 |
Publication Date |
2011-10-18 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0370-1972; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.674 |
Times cited |
13 |
Open Access |
|
Notes |
; Discussions with G. Heger, B. Partoens and F. M. Peeters are gratefully acknowledged. This work has been supported by the Flemish Science Foundation (FWO-Vl) and the Bijzonder Onderzoeksfonds, Universiteit Antwerpen (BOF-UA). ; |
Approved |
Most recent IF: 1.674; 2011 IF: 1.316 |
Call Number |
UA @ lucian @ c:irua:94034 |
Serial |
3618 |
Permanent link to this record |
|
|
|
Author |
Michel, K.H.; Verberck, B. |
Title |
Theoretical phonon dispersions in monolayers and multilayers of hexagonal boron-nitride |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Physica status solidi: B: basic research |
Abbreviated Journal |
Phys Status Solidi B |
Volume |
246 |
Issue |
11/12 |
Pages |
2802-2805 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Starting from an empirical force constant model of valence interactions and calculating by Ewald's method the electrostatic force constants, we derive the dynamical matrix for a monolayer and for multilayer systems of hexagonal boron nitride (h-BN). Solution of the secular problem leads to the corresponding phonon dispersion relations. The interplay between valence forces and Coulomb forces is discussed. A comparison with previous results on graphene and graphene multilayers is made. Our spectra on the h-BN monolayer are rather similar to previous ab initio theory results. Comparison is also made with Raman and infrared experimental results. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Berlin |
Editor |
|
Language |
|
Wos |
000272904100091 |
Publication Date |
2009-11-12 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0370-1972; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.674 |
Times cited |
10 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 1.674; 2009 IF: 1.150 |
Call Number |
UA @ lucian @ c:irua:80673 |
Serial |
3609 |
Permanent link to this record |
|
|
|
Author |
Michel, K.H.; Copley, J.R.D.; Neumann, D.A. |
Title |
Microscopic theory of orientational disorder and the orientational phase transition in solid C60 |
Type |
A1 Journal article |
Year |
1992 |
Publication |
Physical review letters |
Abbreviated Journal |
Phys Rev Lett |
Volume |
68 |
Issue |
19 |
Pages |
2929-2932 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We have developed a microscopic theory which describes the orientational dynamics of C60 molecules in the face-centered-cubic phase of C60 fullerite. The molecular interaction potential and the crystal-field potential are formulated in terms of symmetry-adapted rotator functions. The phase transition to the Pa3BAR structure is driven by an active multipolar mode of T2g symmetry belonging to the l = 10 manifold. The Birman criterion is satisfied. The transition is found to be of first order. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
|
Language |
|
Wos |
A1992HT64800019 |
Publication Date |
2002-07-27 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0031-9007; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
7.512 |
Times cited |
94 |
Open Access |
|
Notes |
|
Approved |
|
Call Number |
UA @ lucian @ c:irua:95492 |
Serial |
2032 |
Permanent link to this record |
|
|
|
Author |
Michel, K.H.; Nikolaev, A.V. |
Title |
Theory of distinct crystal structures of polymerized fullerides AC60, A=K, Rb, Cs: the specific role of alkalis |
Type |
A1 Journal article |
Year |
2000 |
Publication |
Physical review letters |
Abbreviated Journal |
Phys Rev Lett |
Volume |
85 |
Issue |
|
Pages |
3197-3200 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
|
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
|
Language |
|
Wos |
000089807800033 |
Publication Date |
2002-07-27 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0031-9007;1079-7114; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
8.462 |
Times cited |
16 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 8.462; 2000 IF: 6.462 |
Call Number |
UA @ lucian @ c:irua:34339 |
Serial |
3615 |
Permanent link to this record |
|
|
|
Author |
Bussmann-Holder, A.; Michel, K.H. |
Title |
The isotope effect in hydrogen-bonded systems |
Type |
A1 Journal article |
Year |
1998 |
Publication |
International journal of modern physics: B: condensed matter physics, statistical physics, applied physics
T2 – 1st International Conference on New Theories, Discoveries, and, Applications of Superconductors and Related Materials (New3SC-1), FEB 19-24, 19 |
Abbreviated Journal |
Int J Mod Phys B |
Volume |
12 |
Issue |
29-31 |
Pages |
3406-3408 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
The giant isotope effect on the ferro- and antiferroelectric transition temperature upon deuteration of hydrogen-bonded systems is well known experimentally since various decades. Yet, theoretically only recently a microscopic understanding of this effect has been achieved which, specifically, took into account the geometry of the O ... H ... O bond. The implications of this modeling are multiple as numerous hydrogen-bonded organic systems show the same effects as ferro- and antiferroelectrics, i.e., cooperative proton tunneling at a well-defined temperature. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Singapore |
Editor |
|
Language |
|
Wos |
000079114500104 |
Publication Date |
2003-10-01 |
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 |
Impact Factor |
0.736 |
Times cited |
|
Open Access |
|
Notes |
|
Approved |
Most recent IF: 0.736; 1998 IF: 0.987 |
Call Number |
UA @ lucian @ c:irua:102920 |
Serial |
3589 |
Permanent link to this record |
|
|
|
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 |
|
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000251355800092 |
Publication Date |
2007-10-19 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0370-1972;1521-3951; |
ISBN |
|
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 |
|
|
|
Author |
Copley, J.R.D.; Michel, K.H. |
Title |
Neutron and X-ray scattering cross sections of orientationally disordered solid C60 |
Type |
A1 Journal article |
Year |
1993 |
Publication |
Journal Of Physics-Condensed Matter |
Abbreviated Journal |
J Phys-Condens Mat |
Volume |
5 |
Issue |
|
Pages |
4353-4370 |
Keywords |
A1 Journal article; Electron Microscopy for Materials Science (EMAT); |
Abstract |
|
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
London |
Editor |
|
Language |
|
Wos |
A1993LK74100008 |
Publication Date |
0000-00-00 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0953-8984 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.346 |
Times cited |
34 |
Open Access |
|
Notes |
|
Approved |
MATERIALS SCIENCE, MULTIDISCIPLINARY 96/271 Q2 # |
Call Number |
UA @ lucian @ c:irua:5778 |
Serial |
2297 |
Permanent link to this record |
|
|
|
Author |
Copley, J.R.D.; Michel, K.H. |
Title |
Neutron and X-ray-scattering cross sections of orientationally disordered solid C60 |
Type |
A1 Journal article |
Year |
1993 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
Volume |
5 |
Issue |
26 |
Pages |
4353-4370 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Differential cross sections for neutron and x-ray scattering have been derived for the orientationally disordered phase of solid C60. Interaction centres are placed at nuclei and at the centres of interatomic bonds. Bragg and diffuse scattering cross sections, for single crystals and for powders, are formulated using symmetry-adapted rotator functions. Thermal averages are calculated taking account of crystal field effects. Thermally averaged orientational distribution functions have also been calculated. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
London |
Editor |
|
Language |
|
Wos |
A1993LK74100008 |
Publication Date |
2002-08-25 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0953-8984;1361-648X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.346 |
Times cited |
34 |
Open Access |
|
Notes |
|
Approved |
MATERIALS SCIENCE, MULTIDISCIPLINARY 96/271 Q2 # |
Call Number |
UA @ lucian @ c:irua:102972 |
Serial |
2298 |
Permanent link to this record |
|
|
|
Author |
Bostoen, C.; Michel, K.H. |
Title |
Dynamics of a quadrupolar glass |
Type |
A1 Journal article |
Year |
1991 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
43 |
Issue |
|
Pages |
4415-4422 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
|
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
Language |
|
Wos |
A1991EX92100073 |
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 |
33 |
Open Access |
|
Notes |
|
Approved |
no |
Call Number |
UA @ lucian @ c:irua:939 |
Serial |
773 |
Permanent link to this record |
|
|
|
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 |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
Language |
|
Wos |
A1992JK72500049 |
Publication Date |
2002-07-27 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0163-1829;1095-3795; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.736 |
Times cited |
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 |
|
|
|
Author |
Nikolaev, A.V.; Prassides, K.; Michel, K.H. |
Title |
Charge transfer and polymer phases in AC60 (A=K, Rb, Cs) fullerides |
Type |
A1 Journal article |
Year |
1998 |
Publication |
The journal of chemical physics |
Abbreviated Journal |
J Chem Phys |
Volume |
108 |
Issue |
|
Pages |
4912-4923 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
|
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
|
Language |
|
Wos |
000072588400025 |
Publication Date |
2002-07-26 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0021-9606; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.965 |
Times cited |
14 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.965; 1998 IF: 3.147 |
Call Number |
UA @ lucian @ c:irua:23985 |
Serial |
338 |
Permanent link to this record |
|
|
|
Author |
Michel, K.H. |
Title |
Molecular structure and orientational ordering in solid C60 |
Type |
A1 Journal article |
Year |
1992 |
Publication |
The journal of chemical physics |
Abbreviated Journal |
J Chem Phys |
Volume |
97 |
Issue |
7 |
Pages |
5155-5162 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
A microscopic theory, which describes the orientational dynamics of C60 molecules in the face-centered cubic phase of C60-fullerite, is formulated or the case of a complex molecular structure. Interaction centers which comprise atoms, double bonds, and single bonds as molecular constituents contribute to the intermolecular potential. Orientation dependent physical properties are described in terms of symmetry-adapted rotator functions. It is found that a same set of rotator functions is sufficient even in the case of a complex molecular structure. Phase transition temperatures are discussed for various models of molecular structure. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
|
Language |
|
Wos |
A1992JR33800062 |
Publication Date |
2002-07-26 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0021-9606; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.952 |
Times cited |
20 |
Open Access |
|
Notes |
|
Approved |
no |
Call Number |
UA @ lucian @ c:irua:2973 |
Serial |
2185 |
Permanent link to this record |
|
|
|
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 |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
|
Language |
|
Wos |
000175905800044 |
Publication Date |
2002-07-26 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0021-9606; |
ISBN |
|
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 |
|
|
|
Author |
Nikolaev, A.V.; Michel, K.H. |
Title |
Microscopic theory of the rhombohedral phase and transition to the monoclinic phase of solid C70 |
Type |
A1 Journal article |
Year |
1996 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
54 |
Issue |
18 |
Pages |
12733-12743 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Starting from a model of microscopic interactions between C-70 molecules, we have developed a theory which describes the orientational dynamics and its coupling to lattice displacements in the rhombohedral phase of C-70 fullerite. The Landau free energy is calculated. We obtain a first-order phase transition to a monoclinic structure with the space group P2(1)/m. The transition is driven by the condensation of orientational quadrupoles at the F point of the Brillouin zone of the rhombohedral lattice. We find no evidence that the monoclinic structure is connected with the freezing in of orientations around the fivefold molecular axis. We calculate the lattice strains that are associated with the transition to the monoclinic structure. The theory is compared with a range of experimental data on the phase transition. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
Language |
|
Wos |
A1996VT68200028 |
Publication Date |
2002-07-27 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0163-1829;1095-3795; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.736 |
Times cited |
5 |
Open Access |
|
Notes |
|
Approved |
no |
Call Number |
UA @ lucian @ c:irua:16357 |
Serial |
2034 |
Permanent link to this record |
|
|
|
Author |
Neek-Amal, M.; Beheshtian, J.; Sadeghi, A.; Michel, K.H.; Peeters, F.M. |
Title |
Boron nitride mono layer : a strain-tunable nanosensor |
Type |
A1 Journal article |
Year |
2013 |
Publication |
The journal of physical chemistry: C : nanomaterials and interfaces |
Abbreviated Journal |
J Phys Chem C |
Volume |
117 |
Issue |
25 |
Pages |
13261-13267 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
Abstract |
The influence of triaxial in-plane strain on the electronic properties of a hexagonal boron-nitride sheet is investigated using density functional theory. Different from graphene, the triaxial strain localizes the molecular orbitals of the boron-nitride flake in its center depending on the direction of the applied strain. The proposed technique for localizing the molecular orbitals that are close to the Fermi level in the center of boron nitride flakes can be used to actualize engineered nanosensors, for instance, to selectively detect gas molecules. We show that the central part of the strained flake adsorbs polar molecules more strongly as compared with an unstrained sheet. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
Language |
|
Wos |
000321236400041 |
Publication Date |
2013-06-03 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1932-7447;1932-7455; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.536 |
Times cited |
38 |
Open Access |
|
Notes |
; This work was supported by the EU-Marie Curie IIF postdoc Fellowship/299855 (for M.N.-A.), the ESF EuroGRAPHENE project CONGRAN, the Flemish Science Foundation (FWO-VI), and the Methusalem Funding of the Flemish government. AS. would like to thank the Universiteit Antwerpen for its hospitality. ; |
Approved |
Most recent IF: 4.536; 2013 IF: 4.835 |
Call Number |
UA @ lucian @ c:irua:109829 |
Serial |
249 |
Permanent link to this record |
|
|
|
Author |
Callebaut, A.K.; Michel, K.H. |
Title |
Microscopic theory of orientational disorder and lattice instability in solid C70 |
Type |
A1 Journal article |
Year |
1995 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
52 |
Issue |
21 |
Pages |
15279-15290 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We have developed a microscopic theory which describes the orientational dynamics of C-70 molecules and its coupling to lattice displacements in the face-centered-cubic phase of C-70 fullerite. The single-molecule orientational density distribution in the disordered phase is calculated. The ferroelastic transition to the rhombohedral phase is investigated. The discontinuity of the orientational order parameter at the phase transition is calculated. It is found that the transition leads to a stretching of the primitive unit cell along a [111] cubic direction. A softening of the elastic constant c(44) at the transition is predicted. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
Language |
|
Wos |
A1995TK97900042 |
Publication Date |
2002-07-27 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0163-1829;1095-3795; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.736 |
Times cited |
20 |
Open Access |
|
Notes |
|
Approved |
PHYSICS, APPLIED 28/145 Q1 # |
Call Number |
UA @ lucian @ c:irua:104421 |
Serial |
2031 |
Permanent link to this record |
|
|
|
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 |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
Language |
|
Wos |
000243895600128 |
Publication Date |
2007-01-17 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
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 |
|
|
|
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 |
|
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
Language |
|
Wos |
000239426800113 |
Publication Date |
2006-07-22 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
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 |
|
|
|
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. |
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Wos |
000185240100038 |
Publication Date |
2003-08-29 |
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ISSN |
0163-1829;1095-3795; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
15 |
Open Access |
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Notes |
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Approved |
Most recent IF: 3.836; 2003 IF: NA |
Call Number |
UA @ lucian @ c:irua:94847 |
Serial |
3405 |
Permanent link to this record |