New Decoration Techniques for Revealing Antiparallel 180° Domains in BaTiO3

Abstract
Domain structures in BaTiO3 crystals were observed by decorating the surface with Cd or PbCl2. Cd films were formed by evaporation only on the positive ends of c domain and on a-domains when the crystal had been pre-sensitized in AgNO3 solution. Fine crystals of PbCl2 were crystallized most densely on the negative ends of domains from a saturated solution of PbCl2 and the differences in the density of the fine crystals revealed the domain structures clearly. The mechanisms of both decoration phenomena are not yet clear, but the PbCl2 decoration may be closely related to the mechanism of etching by hydrochloric acid of BaTiO3 crystals.