PRODUCTION OF OXIDE

PURPOSE:To inexpensively produce perovskite type oxide having narrow particle size distribution, approximately spherical shape and submicron size, shown by a formula ABO3, by subjecting a hydrolyzate of a peroxide of an element of group B and a hydroxide of an element of group A to hydrothermal reaction. CONSTITUTION:A peroxide (e.g. pertitanic acid, perzirconic acid, slul fatoperhafnium acid, etc., alkali metallic salt thereof, ammonium pertitanate, etc.) of an element (Ti, Zr or Hf) of group B is hydrolyzed. The prepared hydrolyzate is blended with a hydroxide [e.g. Sr(OH)2, Ba(OH)2, Pb(OH)2, these hydroxides containing crystal water or BaO, SrO, etc., becoming hydroxide by reaction with water] of an element (Sr, Ba or Pb) of group A, made into an alkali aqueous slurry and subjected to hydrothermal reaction. A pervoskite type oxide having a composition of ABO3, narrow particle size distribution, approximately spherical shape and submicron size can be inexpensively pro duced.