In:
The Journal of Chemical Physics, AIP Publishing, Vol. 99, No. 10 ( 1993-11-15), p. 8105-8114
Abstract:
Rotations of the molecules about their long axis constitute an important part in the complex pattern of internal motions in the rhombohedral phase of perfluoro-n-eicosane (C20F42). Dynamical studies were performed by quasielastic and inelastic neutron scattering. Spectra were determined in a range of strong diffuse scattering. They show a superposition of librations (δE≂1–2 meV) and rotational diffusion (δE≂10–100 μeV). Reorientation rates exhibit a slowing down on approaching the transition to the low temperature phase (Tc=200 K). As indicated by this slowing down, by the nonexponential relaxation function, and also an intensity enhancement at the Bragg-positions, rotations occur correlated between neighboring molecules. The state of motion can be simulated by molecular dynamics calculations performed for a two-dimensional lattice of coupled rotators.
Type of Medium:
Online Resource
ISSN:
0021-9606
,
1089-7690
Language:
English
Publisher:
AIP Publishing
Publication Date:
1993
detail.hit.zdb_id:
3113-6
detail.hit.zdb_id:
1473050-9
Permalink