Low-temperature polarization in impure SrTiO3 ceramics

Abstract

Measurements of the temperature dependence of the dielectric constant and polarization in a constant field have been made on nominally pure SrTiO3 ceramics and SrTiO3 ceramics containing vanadium and niobium impurities. The peaks in the dielectric constant and the remanent polarization observed are apparently not due to a ferroelectric or antiferroelectric transition but rather to the presence of a thermoelectret state existing for permanent dipoles in the materials. It is suggested that the permanent dipoles have an origin similar to the impurity-vacancy dipoles found in alkali halides.