| 摘要 |
PURPOSE: Methods for preparing barium titanate (BaTiO3) and Perovskite-type complex oxide are provided, to improve its composition and uniformity in size. CONSTITUTION: Barium titanate is prepared by adding liquid ammonia to 0.5-2.0 mol/L of the titanium chloride solution to prepare hydrogenated titania; mixing the hydrogenated titania with 0.5-2.0 mol/L of the aqueous solution of barium nitrate or barium chloride to prepare sludge; spray-drying or lyophilizing the sludge to obtain granule having the mean size of 10-100 micrometers; cracking the granule at the temperature of 650-1,200°C; and pulverizing the cracked one. Perovskite-type complex oxide (ABO3 type) is prepared by adding liquid ammonia to the aqueous solution containing B element to prepare the mixed hydrate; mixing the hydrate with the aqueous solution containing A element to prepare sludge; spray-drying or lyophilizing the sludge to obtain granule; cracking the granule; and pulverizing the cracked one. Preferably the A element is selected from Sr, Ca, Mg, Pb and Ba and the B element is selected from Ti, Zr, Hf and Sn. |
