|
Records |
Links |
|
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 |
Michel, K.H. |
|
|
Title |
Sequence of orientational phase transitions in solid C60 |
Type |
A1 Journal article |
|
Year |
1992 |
Publication |
Chemical physics letters |
Abbreviated Journal |
Chem Phys Lett |
|
|
Volume |
193 |
Issue |
|
Pages |
478-480 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
|
Abstract |
|
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
|
|
Language |
|
Wos |
A1992HZ32900006 |
Publication Date |
2002-07-25 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0009-2614; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
1.897 |
Times cited |
14 |
Open Access |
|
|
|
Notes |
|
Approved |
MATERIALS SCIENCE, MULTIDISCIPLINARY 96/271 Q2 # |
|
|
Call Number |
UA @ lucian @ c:irua:2971 |
Serial |
2985 |
|
Permanent link to this record |
|
|
|
|
Author |
Michel, K.H. |
|
|
Title |
Free energy and orientational phase transition in solid C60 |
Type |
A1 Journal article |
|
Year |
1992 |
Publication |
Zeitschrift für Physik: B |
Abbreviated Journal |
|
|
|
Volume |
88 |
Issue |
|
Pages |
71-78 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
|
Abstract |
|
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
A1992JB10700009 |
Publication Date |
2005-04-28 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0722-3277;1434-6036; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
|
Times cited |
33 |
Open Access |
|
|
|
Notes |
|
Approved |
no |
|
|
Call Number |
UA @ lucian @ c:irua:2967 |
Serial |
1275 |
|
Permanent link to this record |
|
|
|
|
Author |
Nikolaev, A.V.; Michel, K.H. |
|
|
Title |
Quantum charge density fluctuations and the γ-α phase transition in Ce |
Type |
A1 Journal article |
|
Year |
1999 |
Publication |
European physical journal : B : condensed matter and complex systems |
Abbreviated Journal |
Eur Phys J B |
|
|
Volume |
9 |
Issue |
|
Pages |
619-634 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
|
Abstract |
|
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
Berlin |
Editor |
|
|
|
Language |
|
Wos |
000081615500009 |
Publication Date |
2002-08-25 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
1434-6028; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
1.461 |
Times cited |
19 |
Open Access |
|
|
|
Notes |
|
Approved |
Most recent IF: 1.461; 1999 IF: 1.705 |
|
|
Call Number |
UA @ lucian @ c:irua:28504 |
Serial |
2774 |
|
Permanent link to this record |
|
|
|
|
Author |
Lamoen, D.; Michel, K.H. |
|
|
Title |
Coupling of orientational and translational modes in solid C60 and C70 |
Type |
A1 Journal article |
|
Year |
1999 |
Publication |
Phase transitions |
Abbreviated Journal |
Phase Transit |
|
|
Volume |
67 |
Issue |
|
Pages |
789 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
|
Abstract |
|
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
New York |
Editor |
|
|
|
Language |
|
Wos |
000079806300017 |
Publication Date |
2007-07-08 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0141-1594;1029-0338; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
1.06 |
Times cited |
2 |
Open Access |
|
|
|
Notes |
|
Approved |
Most recent IF: 1.06; 1999 IF: 0.622 |
|
|
Call Number |
UA @ lucian @ c:irua:27830 |
Serial |
537 |
|
Permanent link to this record |
|
|
|
|
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 |
|
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 |
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 |
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 |
Scuracchio, P.; Michel, K.H.; Peeters, F.M. |
|
|
Title |
Phonon hydrodynamics, thermal conductivity, and second sound in two-dimensional crystals |
Type |
A1 Journal article |
|
Year |
2019 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
|
|
Volume |
99 |
Issue |
14 |
Pages |
144303 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
|
Abstract |
Starting from our previous work in which we obtained a system of coupled integrodifferential equations for acoustic sound waves and phonon density fluctuations in two-dimensional (2D) crystals, we derive here the corresponding hydrodynamic equations, and we study their consequences as a function of temperature and frequency. These phenomena encompass propagation and damping of acoustic sound waves, diffusive heat conduction, second sound, and Poiseuille heat flow, all of which are characterized by specific transport coefficients. We calculate these coefficients by means of correlation functions without using the concept of relaxation time. Numerical calculations are performed as well in order to show the temperature dependence of the transport coefficients and of the thermal conductivity. As a consequence of thermal tension, mechanical and thermal phenomena are coupled. We calculate the dynamic susceptibilities for displacement and temperature fluctuations and study their resonances. Due to the thermomechanical coupling, the thermal resonances such as the Landau-Placzek peak and the second-sound doublet appear in the displacement susceptibility, and conversely the acoustic sound wave doublet appears in the temperature susceptibility, Our analytical results not only apply to graphene, but they are also valid for arbitrary 2D crystals with hexagonal symmetry, such as 2D hexagonal boron nitride, 2H-transition-metal dichalcogenides, and oxides. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000464717300006 |
Publication Date |
2019-04-10 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
3.836 |
Times cited |
16 |
Open Access |
|
|
|
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl). ; |
Approved |
Most recent IF: 3.836 |
|
|
Call Number |
UA @ admin @ c:irua:159346 |
Serial |
5225 |
|
Permanent link to this record |
|
|
|
|
Author |
Michel, K.H.; Scuracchio, P.; Peeters, F.M. |
|
|
Title |
Sound waves and flexural mode dynamics in two-dimensional crystals |
Type |
A1 Journal article |
|
Year |
2017 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
|
|
Volume |
96 |
Issue |
9 |
Pages |
094302 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
|
Abstract |
Starting from a Hamiltonian with anharmonic coupling between in-plane acoustic displacements and outof-plane (flexural) modes, we derived coupled equations of motion for in-plane displacements correlations and flexural mode density fluctuations. Linear response theory and time-dependent thermal Green's functions techniques are applied in order to obtain different response functions. As external perturbations we allow for stresses and thermal heat sources. The displacement correlations are described by a Dyson equation where the flexural density distribution enters as an additional perturbation. The flexural density distribution satisfies a kinetic equation where the in-plane lattice displacements act as a perturbation. In the hydrodynamic limit this system of coupled equations is at the basis of a unified description of elastic and thermal phenomena, such as isothermal versus adiabatic sound motion and thermal conductivity versus second sound. The general theory is formulated in view of application to graphene, two-dimensional h-BN, and 2H-transition metal dichalcogenides and oxides. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
American Physical Society |
Place of Publication |
New York, N.Y |
Editor |
|
|
|
Language |
|
Wos |
000409246200003 |
Publication Date |
2017-09-05 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
3.836 |
Times cited |
6 |
Open Access |
|
|
|
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem program. ; |
Approved |
Most recent IF: 3.836 |
|
|
Call Number |
UA @ lucian @ c:irua:145630 |
Serial |
4751 |
|
Permanent link to this record |
|
|
|
|
Author |
Michel, K.H.; Çakir, D.; Sevik, C.; Peeters, F.M. |
|
|
Title |
Piezoelectricity in two-dimensional materials : comparative study between lattice dynamics and ab initio calculations |
Type |
A1 Journal article |
|
Year |
2017 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
|
|
Volume |
95 |
Issue |
95 |
Pages |
125415 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
|
Abstract |
The elastic constant C-11 and piezoelectric stress constant e(1),(11) of two-dimensional (2D) dielectric materials comprising h-BN, 2H-MoS2, and other transition-metal dichalcogenides and dioxides are calculated using lattice dynamical theory. The results are compared with corresponding quantities obtained with ab initio calculations. We identify the difference between clamped-ion and relaxed-ion contributions with the dependence on inner strains which are due to the relative displacements of the ions in the unit cell. Lattice dynamics allows us to express the inner-strain contributions in terms of microscopic quantities such as effective ionic charges and optoacoustical couplings, which allows us to clarify differences in the piezoelectric behavior between h-BN and MoS2. Trends in the different microscopic quantities as functions of atomic composition are discussed. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
American Physical Society |
Place of Publication |
New York, N.Y |
Editor |
|
|
|
Language |
|
Wos |
000396013400005 |
Publication Date |
2017-03-11 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
3.836 |
Times cited |
29 |
Open Access |
|
|
|
Notes |
; The authors acknowledge useful discussions with L. Wirtz and A. Molina-Sanchez. This work was supported by the Methusalem program and the Fonds voor Wetenschappelijk Onderzoek-Vlaanderen. Computational resources were provided by HPC infrastructure of the University of Antwerp (CalcUA), a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation. ; |
Approved |
Most recent IF: 3.836 |
|
|
Call Number |
UA @ lucian @ c:irua:142444 |
Serial |
4603 |
|
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 |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
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 |
|
|
|
|
Author |
Michel, K.H.; Costamagna; Peeters, F.M. |
|
|
Title |
Theory of anharmonic phonons in two-dimensional crystals |
Type |
A1 Journal article |
|
Year |
2015 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
|
|
Volume |
91 |
Issue |
91 |
Pages |
134302 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
|
Abstract |
Anharmonic effects in an atomic monolayer thin crystal with honeycomb lattice structure are investigated by analytical and numerical lattice dynamical methods. Starting from a semiempirical model for anharmonic couplings of third and fourth orders, we study the in-plane and out-of-plane (flexural) mode components of the generalized wave vector dependent Gruneisen parameters, the thermal tension and the thermal expansion coefficients as a function of temperature and crystal size. From the resonances of the displacement-displacement correlation functions, we obtain the renormalization and decay rate of in-plane and flexural phonons as a function of temperature, wave vector, and crystal size in the classical and in the quantum regime. Quantitative results are presented for graphene. There, we find that the transition temperature T-alpha from negative to positive thermal expansion is lowered with smaller system size. Renormalization of the flexural mode has the opposite effect and leads to values of T-alpha approximate to 300 K for systems of macroscopic size. Extensive numerical analysis throughout the Brillouin zone explores various decay and scattering channels. The relative importance of normal and umklapp processes is investigated. The work is complementary to crystalline membrane theory and computational studies of anharmonic effects in two-dimensional crystals. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
|
|
Language |
|
Wos |
000353031000001 |
Publication Date |
2015-04-17 |
|
|
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 |
38 |
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 EuroGRAPHENE project CONGRAN. ; |
Approved |
Most recent IF: 3.836; 2015 IF: 3.736 |
|
|
Call Number |
UA @ lucian @ c:irua:132512 |
Serial |
4263 |
|
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 |
|
|
|
Corporate Author |
|
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.; Lamoen, D.; David, W.I.F. |
|
|
Title |
Orientational order and disorder in solid C60 : theory and diffraction experiments |
Type |
A1 Journal article |
|
Year |
1995 |
Publication |
Acta crystallographica: section A: foundations of crystallography |
Abbreviated Journal |
Acta Crystallogr A |
|
|
Volume |
51 |
Issue |
3 |
Pages |
365-374 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
|
Abstract |
Starting from a microscope model of the intermolecular potential, a unified description is presented of the Bragg scattering law in the orientationally disordered and in the ordered phase of solid C-60. The orientational structure factor is expanded in terms of symmetry-adapted surface harmonics. The expansion coefficients are calculated from theory and compared with experiment Their temperature evolution is studied in the disordered phase at the 260 K transitions and in the ordered phase. In the ordered phase, new results from high-resolution neutron powder diffraction are given. In the disordered phase, space group Fm $($) over bar$$ 3m, the reflections have A(1g) symmetry; in the ordered phase, space group Pa $$($) over bar 3, reflections of T-2g symmetry appear and in addition the A(1g) reflections are renormalized. The orientational density distribution is calculated. The effective crystal-field potential is constructed, its temperature evolution in the ordered phase is studied and related to the occurrence of an orientational glass. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
Copenhagen |
Editor |
|
|
|
Language |
|
Wos |
A1995RB59400018 |
Publication Date |
2002-07-27 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0108-7673; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
2.307 |
Times cited |
14 |
Open Access |
|
|
|
Notes |
|
Approved |
CHEMISTRY, MULTIDISCIPLINARY 65/163 Q2 # CRYSTALLOGRAPHY 10/26 Q2 # |
|
|
Call Number |
UA @ lucian @ c:irua:12189 |
Serial |
2518 |
|
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 |
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 |
|
|
|
Corporate Author |
|
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 |
|
|
|
|
Author |
Beheshtian, J.; Sadeghi, A.; Neek-Amal, M.; Michel, K.H.; Peeters, F.M. |
|
|
Title |
Induced polarization and electronic properties of carbon-doped boron nitride nanoribbons |
Type |
A1 Journal article |
|
Year |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
|
|
Volume |
86 |
Issue |
19 |
Pages |
195433-195438 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
|
Abstract |
The electronic properties of boron nitride nanoribbons (BNNRs) doped with a line of carbon atoms are investigated using density functional calculations. By replacing a line of alternating B and N atoms with carbons, three different configurations are possible depending on the type of the atoms which bond to the carbons. We found very different electronic properties for these configurations: (i) the NCB arrangement is strongly polarized with a large dipole moment having an unexpected direction, (ii) the BCB and NCN arrangements are nonpolar with zero dipole moment, (iii) the doping by a carbon line reduces the band gap regardless of the local arrangement of the borons and the nitrogens around the carbon line, and (iv) the polarization and energy gap of the carbon-doped BNNRs can be tuned by an electric field applied parallel to the carbon line. Similar effects were found when either an armchair or zigzag line of carbon was introduced. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000311694200006 |
Publication Date |
2012-11-29 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
3.836 |
Times cited |
41 |
Open Access |
|
|
|
Notes |
; We would like to thank J. M. Pereira and S. Goedecker for helpful discussions. This work was supported by the Flemish Science Foundation (FWO-Vl), the ESF-EuroGRAPHENE project CONGRAN. M. N.-A is supported by EU-Marie Curie IIF postdoc Fellowship/299522. ; |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
|
|
Call Number |
UA @ lucian @ c:irua:105136 |
Serial |
1603 |
|
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 |
Copley, J.R.D.; Michel, K.H. |
|
|
Title |
Multiple orientational order parameters in solid C60 |
Type |
A1 Journal article |
|
Year |
1997 |
Publication |
Physica: B : condensed matter
T2 – International Conference on Neutron Scattering, AUG 17-21, 1997, TORONTO, CANADA |
Abbreviated Journal |
Physica B |
|
|
Volume |
241 |
Issue |
|
Pages |
454-455 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
|
Abstract |
The transition Fm (3) over bar m -->Pa (3) over bar in solid C-60 is driven by the condensation of orientational modes belonging to X-5(+) irreducible representations (irreps) of Fm (3) over bar m. Taking into account irreps up to the manifold l = 12, we have studied the primary and secondary orientational order parameters loops). We have numerically solved the coupled molecular field equations for these oops and calculated the temperature dependence of Bragg reflection intensities. (C) 1998 Elsevier Science B.V. All rights reserved. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
|
|
Language |
|
Wos |
000074062600130 |
Publication Date |
2002-07-25 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0921-4526; |
ISBN |
|
Additional Links |
UA library record; WoS full record |
|
|
Impact Factor |
1.386 |
Times cited |
|
Open Access |
|
|
|
Notes |
|
Approved |
Most recent IF: 1.386; 1997 IF: 0.991 |
|
|
Call Number |
UA @ lucian @ c:irua:104360 |
Serial |
2228 |
|
Permanent link to this record |
|
|
|
|
Author |
Nikolaev, A.V.; Michel, K.H. |
|
|
Title |
Many electron- and hole terms of molecular ions C60n\pm |
Type |
A1 Journal article |
|
Year |
2003 |
Publication |
Coupling In Chemistry And Physics |
Abbreviated Journal |
Adv Quantum Chem |
|
|
Volume |
44 |
Issue |
|
Pages |
305-312 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
|
Abstract |
|
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
|
|
|
Language |
|
Wos |
000188940800019 |
Publication Date |
2004-05-19 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0065-3276; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
1.196 |
Times cited |
1 |
Open Access |
|
|
|
Notes |
|
Approved |
Most recent IF: 1.196; 2003 IF: 0.375 |
|
|
Call Number |
UA @ lucian @ c:irua:104131 |
Serial |
1942 |
|
Permanent link to this record |
|
|
|
|
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 |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000228763100035 |
Publication Date |
2005-04-27 |
|
|
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 |
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 |
|
|
|
|
Author |
Nikolaev, A.V.; Michel, K.H. |
|
|
Title |
Ab initio approach to superexchange interactions in alkali doped fullerides AC60 |
Type |
P1 Proceeding |
|
Year |
2004 |
Publication |
AIP conference proceedings
T2 – 18th International Winterschool/Euroconference on Electronic Properties, of Novel Materials, MAR 06-JUN 13, 2004, Kirchberg, AUSTRIA |
Abbreviated Journal |
|
|
|
Volume |
|
Issue |
|
Pages |
393-396 |
|
|
Keywords |
P1 Proceeding; Condensed Matter Theory (CMT) |
|
|
Abstract |
The superexchange interactions between the fullerenes arise as a result of the electron transfer from the C-60 molecule to the alkali atom and back. We present a scheme, which is a configuration interaction approach based on the valence bond (Heitler-London) method. The effect of superexchange is described together with chemical bonding by constructing and solving a secular equation, rather than by using a perturbation treatment. We have considered 180degrees and 90degrees superexchange for the C-60 Cs-C-60 pathways. The calculations account for unusual electronic properties of polymer orthorhombic and quenched cubic phases of CsC60: two lines in nuclear magnetic resonance experiments, the development of a spin-singlet ground state and a decrease of magnetic susceptibility as T-->0. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
New York |
Editor |
|
|
|
Language |
|
Wos |
000224699400085 |
Publication Date |
2004-11-11 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
723 |
Series Issue |
|
Edition |
|
|
|
ISSN |
0-7354-0204-3 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
|
Times cited |
|
Open Access |
|
|
|
Notes |
|
Approved |
Most recent IF: NA |
|
|
Call Number |
UA @ lucian @ c:irua:103752 |
Serial |
27 |
|
Permanent link to this record |
|
|
|
|
Author |
Bussmann-Holder, A.; Dalal, N.; Michel, K.H. |
|
|
Title |
Polarizability induced cooperative proton ordering, coexistence of order/disorder and displacive dynamics and isotope effects in hydrogen-bonded systems |
Type |
A1 Journal article |
|
Year |
2000 |
Publication |
The journal of physics and chemistry of solids
T2 – Williamsburg Workshop on Ferroelectrics 99, JAN 31-FEB 03, 1999, WILLIAMSBURG, VIRGINIA |
Abbreviated Journal |
J Phys Chem Solids |
|
|
Volume |
61 |
Issue |
2 |
Pages |
271-274 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
|
Abstract |
Despite the general belief that hydrogen-bonded ferro- and antiferroelectrics undergo a pure order/disorder transition at the structural instability, new NMR data and a new theoretical concept yield convincing evidence that a pronounced displacive component is present in these systems, which modifies substantially the temperature dependencies of the tunnel and lattice mode frequencies. The experiments and their interpretation are presented. (C) 1999 Elsevier Science Ltd. All rights reserved. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
Pergamon-elsevier science ltd |
Place of Publication |
Oxford |
Editor |
|
|
|
Language |
|
Wos |
000084147000020 |
Publication Date |
2002-07-25 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0022-3697; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
2.059 |
Times cited |
8 |
Open Access |
|
|
|
Notes |
|
Approved |
Most recent IF: 2.059; 2000 IF: 1.003 |
|
|
Call Number |
UA @ lucian @ c:irua:103469 |
Serial |
2660 |
|
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 |
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 |
|
|
|
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 |
|
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 |
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 |
Nikolaev, A.V.; Michel, K.H. |
|
|
Title |
Superexchange and electron correlations in alkali fullerides AC60, A=K, Rb, Cs |
Type |
A1 Journal article |
|
Year |
2005 |
Publication |
The journal of chemical physics |
Abbreviated Journal |
J Chem Phys |
|
|
Volume |
122 |
Issue |
6 |
Pages |
064310-64314 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
|
Abstract |
Superexchange interactions in alkali fullerides AC(60) are derived for C-60 molecular ions separated by interstitial alkali-metal ions. We use a multiconfiguration approach which comprises the lowest molecular orbital states of the C-60 molecule and the excited s and d states of the alkali-metal atom A. Interactions are described by the valence bond (Heitler-London) method for a complex (C-60 – A – C-60) – with two valence electrons. The electronic charge transfer between the alkali-metal atom and a neighboring C-60 molecule is not complete. The occupation probability of excited d and s states of the alkali atom is not negligible. In correspondence with the relative positions of the C-60 molecules and A atoms in the polymer crystal, we consider 180degrees and 90degrees (angle) superexchange pathways. For the former case the ground state is found to be a spin singlet separated from a triplet at similar to20 K. For T < 20 K there appear strong spin correlations for the 180degrees superexchange pathway. The results are related to spin lattice relaxation experiments on CsC60 in the polymerized and in the quenched cubic phase. (C) 2005 American Institute of Physics. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
|
|
|
Language |
|
Wos |
000226918100018 |
Publication Date |
2005-02-02 |
|
|
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 |
11 |
Open Access |
|
|
|
Notes |
|
Approved |
Most recent IF: 2.965; 2005 IF: 3.138 |
|
|
Call Number |
UA @ lucian @ c:irua:102740 |
Serial |
3377 |
|
Permanent link to this record |
|
|
|
|
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 |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000259645200003 |
Publication Date |
2008-09-28 |
|
|
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 |
6 |
Open Access |
|
|
|
Notes |
|
Approved |
Most recent IF: 1.35; 2008 IF: 0.680 |
|
|
Call Number |
UA @ lucian @ c:irua:102640 |
Serial |
1295 |
|
Permanent link to this record |