| 摘要 |
PURPOSE: A preparation method of barium titanate-based powder by oxalate process is provided, which is characterized by including a grinding step of barium titanate oxalate before thermal composition. Accordingly, the resultant powder with spherical and homogeneous particles, and X7R characteristic is widely used for electronic ceramics, especially multilayer ceramic capacitors. CONSTITUTION: The preparation method is as follows: adding oxalic acid to mixed solution of BaCl2 and TiCl4 having a molar ratio Ba/Ti of 1-1.5 to precipitate barium titanate oxalate(BTO), BaTiO(C2O4)2·4H2O; aging for 1-100hrs., washing and filtering; wet-milling to BTO powder less than 5micrometer for preventing agglomeration of BTO powder and occlusion of impurities(Cl ions), and optionally adding additives for ABO3 perovskite BTO powder such as Ba(Ti1-zZrz)03, (Ba1-xCax)(Ti1-zZrz)03, etc., wherein A is Ba and 1-30mol%(based on Ba) of at least one element substituting for Ba selected from Mg, Ca, Sr and Pb, and B is Ti and 1-100mol%(based on Ti) of at least one element substituting for Ti selected from Zr, Hf and Sn; spray drying at 100-450deg.C; and thermal decomposing(calcining) at 700-1200deg.C, wherein the heating rate is 0.5-10deg.C/min.
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