Ultrasound Velocity in TGSe near the Ferroelectric Phase Transition

Abstract

The temperature dependence of elastic stiffness constant C₂₂ and ultrasound velocity of TGSe single crystals have been measured accurately near the ferroelectric phase transition. It is found that the anomalous part of the elastic stiffness constant Δ C₂₂ and that of sound velocity are both proportional to log(T−T_c). The anomalous attenuation Δα^1⁄2 in the paraelectric phase transition is also proportional to log(T−T_c).