PRODUCTION OF EASILY SINTERABLE RAW MATERIAL POWDER OF COMPOUND PEROVSKITE BY MULTISTAGE WET PROCESS

摘要

PURPOSE:To produce easily sinterable raw material powder of perovskite with high efficiency by generating the precipitate of Nb, Ta, Pb, Ti, or Zr stepwise, successively, and generating further the precipitate contg. Mg, etc., in the soln. contg. the first precipitate and having an appropriate pH. CONSTITUTION:Each soln. of component B (Nb or Ta), component Pb, Ti and Zr, is allowed to contact successively with a soln. for forming precipitate such as aq. ammonia, to generate the ppt. of above described each component stepwise, successively. Then, the ion concn. of the soln. derived from the ppt.- forming material in the ppt.-contg. soln. is adjusted to =0.2mol./l by washing the obtd. ppt. Thereafter, the pH of the ppt.-contg. soln. is adjusted to =11.5 with the ppt.-forming soln. The ppt. contg. the component A (at least one among Mg, Zn, Ni, Co) is generated by adding a soln. of hydroxide of the component A to the soln. having =11.5pH. The ppt. obtd. by this process is calcined at ca. 500-1,200 deg.C. Thus, the raw material powder of perovskite expressed by the general formula: x[Pb(A1/3B2/3)O3]-y(PbTiO3)-z(PbZrO3) (wherein x+y+ z=100mol.%) is obtd.