Phase transitions in the vicinity of the lifshitz point in ferroelectric-semiconductors

Abstract

Abstract The critical behaviour of uniaxial proper ferroelectric Sn2P2S6 in the vicinity of second order phase transition from paraelectric to ferroelectric phase was investigated using low frequency dielectric properties temperature behaviour technique. At T − T 0 < 10 K on the temperature dependence of Sn2P2S6 dielectric susceptibility measured in slow cooling mode deviation from the Curie-Weiss law was observed which can be described by logarithmic mulitplicative correction of the type |Inτ|1/3, where τ = (T − T 0)/T 0. It is assumed that the observed critical behaviour of uniaxial ferroelectric is caused by the vicinity of tricritical Lifshitz point in which the line of TCP and the line of LP merge on the phase diagram.