Spontaneous polarization and heat transport anomaly at the overcritical state of ferroelectric MAPCB crystal

Abstract

The results of temperature dependence studies of spontaneous polarization changes in the temperature interval of 4.2–320 K and of thermal conductivity in the temperature range of 100–330 K for MAPCB crystals are presented. It is found that the thermal conductivity anomaly appears mainly in the temperature region where the maximum of the pyroelectric coefficient is observed i.e. in the region of the overcritical trace of the isomorphous phase transition. The results are discussed on the basis of liquid-gas type phase transitions.