PRODUCTION OF SEMICONDUCTIVE SRTIO3 PARTICLE AND HIGH-DIELECTRIC CONSTANT CERAMIC

摘要

PURPOSE:To obtain the titled semiconductor particles having small particle diameter and desirable for a high-capacity laminated capacitor by mixing Sr, Ti, and the compd. of a doping metal, baking the coat particles formed by a sol-gel technique, and baking the formed powder. CONSTITUTION:SrTiO3 powder is impregnated or mixed with the sol-gel soln. of the alkoxide of a doping metal in the protective atmosphere of pure nitrogen or Ar or mixed with the soln. Ethanol, propanol, etc., are appropriately used as the solvent in this case, the concn. of the metallic compd. in the soln. is controlled to about 5-20%, and the soln. contains a small amt. of water and a catalyst such as HCl. The formed gel layer is then dried, and heated to transfer the deposited metal into the oxide. The SrTiO3 powder which is not doped is dipped in the soln. of the alkoxide in an org. solvent, drained, then dried, heated in the air,and burned and reduced. The reduced substance is crushed and then pulverized by a ball mill into ca. 0.5-5mum particle diameter, and the desired semiconductive SrTiO3 particles are obtained.