![Sample our Engineering & Technology journals, sign in here to start your access, latest two full volumes FREE to you for 14 days]({"type":"image" , "src" : "/sda/5933/TOC-Subject-Sample-2021-Engineering-Tech.jpg"})
Abstract
The results of a light scattering model for disordered crystals described in a previous work are applied to the translational spectra of ice I h single crystals. The spectra in all scattering configurations are dominated by density of states structure and only very weak evidence of k=0 symmetry allowed vibrations is found. The scattering model proposed previously is found to be inadequate only in describing the low frequency part of the spectra, which show evidence of a central mode and of an acoustic phonon contribution related, via the Bose population factor, directly to the corresponding density of states.
Zone centre symmetry projected density of states are derived and the entire translational density of states is reconstructed and successfully compared with lattice dynamics calculations. Specific heat values obtained with this density of states follow the experimental data correctly up to 120 K, as expected.
An explanation is suggested for the low frequency excess scattering contribution.
Notes
Work supported by Gruppo Nazionale di Struttura della Materia (C.N.R.) and by M.P.I. (special grant to E. Mazzega).