Anisotropy in Anomalies of Hypersound Velocity and Attenuation in Ferroelectric TSCC

Abstract

From Brillouin shift and linewidth of longitudinal phonons propagating along the [100] and [001] directions of TSCC, the polarization relaxation time was calculated to be τ=3.1×10-12/(Tc-T) sec below the transition temperature Tc. The anomalies in the longitudinal phonons of the [010] propagation were carefully examined using an annealed crystal of excellent quality. No essential difference was observed between the velocities of a normal and high quality crystals. The relaxation time was deduced as a function of temperature from the observed anomalies in the velocity and linewidth. Spectra are observed for nearly forward scattering from the q\varparallel[010] phonons.