Elastic constants of the disordered phase of CBr4 by Brillouin spectroscopy

Abstract

The technique of Brillouin spectroscopy has been used to determine the adiabatic elastic constants of single crystals of the orientationally disordered phase (phase I) of CBr4 .The values of the elastic constants at 333 K are C11 =42.2, C12 =33.6, and C44 =16.1 (in units of kbar) and suggest that there is strong rotation–translation coupling in the k=0 acoustic wave vector regime. Because x-ray Laue diffraction was not possible in solid CBr4 , the necessary orientation of the single crystals was determined by also using the Brillouin scattering spectra.