PREPARATION METHOD OF BATIO3-BASED OXIDES BY OXALATE METHOD

PURPOSE: Provided is an easy and economic preparation method of BaTiO3-based oxides by modified oxalate method which is characterized by having more steps, primary milling, calcination, and secondary milling compared with a conventional oxalate method. The resultant BaTiO3-based oxide powder has spherical shape, mono-size and reproducible Ba/Ti control required for ceramic condensers, PTC and piezoelectrics. CONSTITUTION: The preparation method comprises the steps of: preparing BaCl2/TiCl4 solution by mixing 0.2-2.0mol/l of BaCl2 with 0.2-2.0mol/l of TiCl4 aqueous solution in a molar ratio of 1-1.5; preparing 0.2-5.0mol/l of oxalic acid((COOH)2), where a molar ratio of (COOH)2/TiCl4 is 1-3.0; adding BaCl2/TiCl4 solution at a 1-50ml/l rate to 50-100deg.C of oxalic acid solution for precipitating barium titanic oxalate(BTO, BaTi(C2O4)24H2O); aging for 1-100hrs.; drying at 50-200deg.C; thermal decomposing by heating at 2-10deg.C/min and holding at 600-1000deg.C; optionally substituting one or at least two element selected from Sr, Ca, Mg, Pb for Ba, and substituting one or at least two element selected from Zr, Hf, Sn for Ti; primary milling to 0.1-0.3micrometer of particle diameter; calcining at 800-1200deg.C; secondary milling to 0.2-1micrometer of particle diameter.