Patent ID: 7820136

Claim:
A process for production of compound oxide particles, comprising: contacting an organic phase having dissolved therein an organic compound of a metal alkoxide or an acetonate-metal complex, the metal of said metal alkoxide or acetonate-metal complex being hereinafter referred to as a first element, with an aqueous phase containing a second element as an ion, and a surfactant to form a microemulsion, in which a hydroxide of said first element is produced by a hydrolysis reaction of said organic compound at the interface between said organic and aqueous phases while incorporating said second element in the hydroxide, adding an alkali to the microemulsion to adjust the pH for colloid aggregation adjustment and maturing to form a matured product, and firing the matured product to produce particles of a compound oxide of said first element and second element, wherein said aqueous phase further contains a third or additional elements as ions, said product further contains a third or additional elements, and the obtained compound oxide is a compound oxide of the first, second and third or additional elements.