Analysis of the Dielectric Constant, Spontaneous Polarization and the Coersive Field Close To the Phase Transitions in Ferroelectric K2cocl4

Abstract

Temperature dependence of the dielelctric constant epsilon(a) along a axis and the spontaneous polarization P-S is analyzed near the ferroelectric transition (T-C = 182 degrees C) in K2CoCl4. The power-law formula is used for the analysis of the observed data from the literature. Critical exponents we determine from our analysis indicate that K2CoCl4 exhibits a weak first order transition. Coercive field EC is also analyzed using the experimental data which decreases smoothly as the temperature increases toward the transition temperature T-C. It is concluded that the theoretical model(s) with the non-zero applied electric field, can explain the ferroelectric properties of K2CoCl4 close to the phase transitions.