| 摘要 |
PURPOSE:To produce the titled easily sintering powder having high bulk density in high reproducibility, by successively precipitating B, Pb, Ti and Zr components stepwise, controlling NH4<+> ion concentration and pH of the liquid containing said precipitates and precipitating Mg, Zn, Ni and Co components from the liquid. CONSTITUTION:Powdery raw material of a compound of formula (A is Mg, Zn, Ni or Co; B is Nb or Ta; x, y and z are mol% and x+y+z=100) having composite perovskite-type structure and its solid solution is produced by (1) contacting a solution containing B, Pb, Ti and Zr components with a precipitant liquid to successively produce the precipitate of each component in stepwise, (2) adjusting an NH4<+> ion concentration of the precipitate-containing liquid to <=0.2mol/l and adjusting the pH of the liquid to >=11.5 with a pH-modifier, (3) adding an aqueous solution of the nitrate of the component A to form a precipitate of the component A and (4) calcining the precipitate. The whole components can be completely precipitated by the above successive precipitation process without causing the agglomeration and coagulation of the particles to enable the production of the titled powder having high bulk density in high reproducibility. |
