Hydrothermal synthesis of spherical perovskite oxide powders using spherical gel powders

Abstract

Spherical perovskite oxide powders, composed of fine particulates, were prepared by using spherical gel powders under hydrothermal conditions. Spherical PbTiO3, BaTiO3, and SrTiO3 powders were synthesized from spherical TiO2 gel powders, and spherical PbZrO3 powder from spherical ZrO2 gel powder. Spherical Pb(Zr-0.5, Ti-0.5)O-3 and Ba(Zr0.5Ti0.5)O-3 powders were prepared from spherical ZrTiO4 gel powders, Lead acetate trihydrate, barium hydroxide octahydrate, and strontium hydroxide octahydrate were used as the sources of A-site ions in each perovskite oxide (ABO(3)). The spherical TiO2 and ZrO2 gel powders were prepared by thermal hydrolysis of titanium tetrachloride and zirconium oxychloride, respectively, and spherical ZrTiO4 gel powder by thermal hydrolysis of a mixture of them in alcohol-water mixed solvent, During the hydrothermal treatment, the spherical gel powders retained their spherical shape to produce spherical perovskite oxide powders, composed of nanometer-sized particulates.