Publication
Title
Orientational order and disorder in solid $C_{60}$ : theory and diffraction experiments
Author
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.
Language
English
Source (journal)
Acta crystallographica: section A: foundations of crystallography. - Copenhagen
Publication
Copenhagen : 1995
ISSN
0108-7673
Volume/pages
51:3(1995), p. 365-374
ISI
A1995RB59400018
Full text (Publishers DOI)
UAntwerpen
 Faculty/Department Research group Publication type Subject Affiliation Publications with a UAntwerp address