| 摘要 |
A process for preparing a fine powder of perovskite-type compounds having an average particle size of at most 0.3 mu m and uniform particle sizes, which comprises subjecting to a reaction an aqueous solution of a mixture of at least one compound selected from group A element compounds comprising alkaline earth metal elements and/or bivalent metal elements with at least one compound selected from group B element compounds comprising tetravalent metal elements such as Ti, Zr, Hf and Sn and/or composite metal elements composed of a bivalent or trivalent metal element such as Zn, Ni, Co, Mg, Fe or Sb and a pentavalent metal element such as Nb or Sb in an A/B atomic ratio of more than 1, calcining the resulting powdery reaction product at a temperature which is lower than the temperature at which the growth of particles takes place and which is higher than the temperature at which the growth of particles takes place when A/B is 1, and cleaning the calcined product with an acid solution to remove the excess group A elements. The process provides fine powders of perovskite-type compounds having a good crystallinity, particularly tetragonal barium titanate, which are useful particularly as raw materials of ceramics for electronic devices.
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