Ferroelectric Domain Formation in Short Circuited KH₂PO₄

Abstract

Domain configurations of short circuited KH₂PO₄ crystals have been observed for different formation processes with simultaneous measurements of the dielectric constant. Two types of domain configurations are obtained. One with a large dielectric constant, which contains many fine domains, is obtained by cooling from the paraelectric phase. The other with a small dielectric constant is obtained by decreasing the applied static bias field to zero. Contrary to the widely accepted idea, the ferroelectric domain is formed easily in the absence of the electrostatic depolarization field. A model based upon the spinodal decomposition is proposed to elucidate the domain formation process of the short circuited crystal.