| abstract |
A composite oxide particle having a ratio of an element A to an element M (A / M) close to ideal 1 as a perovskite crystal and an extremely small average crystallite diameter is obtained. One or more elements A selected from Ba, Sr, Ca, Mg, Al, Pb, Co, and Zn and one selected from Ti, Zr, W, Nb, Hf, and Sn A process for producing composite oxide particles containing the above element M and having a perovskite crystal phase composed of element A, element M and oxygen, comprising a precursor containing element A and a precursor containing element M The first step of obtaining a reaction liquid by mixing the element A so that the element A is excessive with respect to the theoretical composition, the second step of subjecting the reaction liquid to a solvothermal method to obtain a synthetic liquid containing a solid content, It comprises a third step of obtaining composite oxide particles by treatment with an acid solution of less than 5% by mass. [Selection] Figure 1 |