Dielectric Residual Effects in Titanates

Abstract

BARIUM TITANATE and certain related compounds having structures of the perovskite type possess exceptionally high permittivities which rise to a maximum at certain characteristic temperatures, a transition taking place from a distorted to a cubic crystal structure. The permittivity – temperature relation depends primarily on the particular material used, but is influenced also by the method of preparation, especially by the temperature at which the ceramic is fired. It has been shown that barium titanate is ferro-electric below the temperature corresponding to its permittivity maximum^1,2, and in this connexion a study of the changes with time in the permittivity and dielectric losses after a high, unidirectional electric field had been applied to materials of this type, which is now described in outline, may be of interest.