Phase Transitions and Disordering Effects in СuInP2(S1-хSeх)6 Layered Ferrielectrics

Abstract

By X-ray diffraction structure determination, together with Raman scattering, optical birefringence and low frequency dielectric measurements, ferrielectric phase transitions in regions of trigonal and monoclinic phases on a temperature—concentration diagram of CuInP2(SexS1−x )6 mixed crystals are investigated. The phase transitions temperatures rapidly decrease and related anomalies smear at deviation from pure compounds. In a middle interval of concentrations a dipole ordering obviously has peculiar character.