Elastic Study of Thiourea near the IV–V Phase Transition

Abstract

The temperature dependences of elastic stiffness constant C₂₂ and attenuation coefficient α₂₂ of thiourea single crystals were measured around the IV–V phase transition. It was found that the anomalous parts of the attenuation coefficient Δ α₂₂ and of the elastic stiffness constant Δ C₂₂ are both proportional to log(T−T₀), in agreement with the formula given by Levanyuk et al. for uniaxial ferroelectric materials.