HYDROTHERMAL SYNTHESIS OF SPHERICAL PEROVSKITE OXIDE POWDERS USING SPHERICAL GEL POWDERS

Spherical perovskite oxide powders, composed of fine particulates, wer e prepared by using spherical gel powders under hydrothermal condition s. 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 acetat e trihydrate, barium hydroxide octahydrate, and strontium hydroxide oc tahydrate were used as the sources of A-site ions in each perovskite o xide (ABO(3)). The spherical TiO2 and ZrO2 gel powders were prepared b y thermal hydrolysis of titanium tetrachloride and zirconium oxychlori de, respectively, and spherical ZrTiO4 gel powder by thermal hydrolysi s of a mixture of them in alcohol-water mixed solvent, During the hydr othermal treatment, the spherical gel powders retained their spherical shape to produce spherical perovskite oxide powders, composed of nano meter-sized particulates.