Phonons and librational excitations in solid CD4I and CD4II
- 28 October 1977
- journal article
- Published by IOP Publishing in Journal of Physics C: Solid State Physics
- Vol. 10 (20) , 3959-3969
- https://doi.org/10.1088/0022-3719/10/20/005
Abstract
Acoustic phonon dispersion curves have been measured by neutron inelastic scattering in phases I and II of solid deuteromethane (CD4), yielding elastic constants CII=3.08+or-0.20, C12=2.14+or-0.24 and C44=1.58+or-0.06 (in units of 1010 dyn cm-2) in phase I. The elastic constants in phase II are about 10% higher. Longitudinal acoustic phonons in the (111) direction indicate life-time broadening. While no well defined librational excitations were observed, there is evidence that inelastic 'shoulders' in the neutron spectra are due to damped librations.Keywords
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