PREPARATION OF (BAXSR1-X)TIO3 PARTICLES BY VAPOR-PHASE HYDROLYSIS OF PRECURSORS FORMED FROM ALKOXIDE-HYDROXIDE

Solutions of Ba and Sr hydroxides in methanol were allowed to react wi th Ti-isopropoxide under conditions of stirring at room temperature fo r 15h, and then dried under reduced pressure at less than or equal to 40 degrees C, to prepare the powder precursors of (BaxSr1-x)TiO3. The powder precursors prepared thus were hydrolyzed by introducing nitroge n gas containing water vapor at 100 degrees C. The hydrolyzed products were crystalline nanosize powders of (BaxSr1-x)TiO3 (x = 0.7) solid s olution with a specific surface area of about 80 m(2)/g. (Ba0.7Sr0.3)T iO3 bodies sintered at 1275 degrees C showed a relatively homogeneous microstructure with grain sizes of 0.3-0.6 mu m and a relative density of 97%. They exhibited a dielectric constant of approximately 4000 an d a tan delta of approximately Ire at room temperature.