On the Possible Curie Temperature and Ferroelectricity for SrTiO3 and KTaO3

Abstract

The low temperature behaviour and possible ferroelectric stability of SrTiO3 and KTaO3 are reexamined. By use of thermodynamic theory and the parameter values in the literature, TC is calculated to be 3.0 K for SrTiO3. It is coincident with the temperature at which a small maximum in the dielectric constant was observed. We assume that weak ferroelectricity may exist in SrTiO3. The TC of KTaO3 is calculated to be below zero. No evidence of ferroelectricity is found for KTaO3 at atmospheric pressure.