Dielectric properties of Tl₂CoCl₄

Abstract

Abstract Crystal of Tl2CoCl4 having orthorhombic β-K2SO4-type structure was obtained by Bridgman method and their dielectric and phase transitional properties were investigated. We found a sharp peak at 73K, a broad maximum at around 120K and a bending curve at 165K in the temperature dependence of dielectric constant. We could observe ferroelectric activity below 73K in the a-direction. The spontaneous polarization P s estimated from D-E hysteresis loop was about 4.5nC/cm2 around 65K.