Patent ID: 7744954

Claim:
A method of producing a powder comprising synthesizing particles in a liquid comprising raw materials of two or more elements, wherein particles different in composition at least between the inside the particle and the surface thereof are obtained by supplying a composition (1) to be incorporated as a component of the particles to the liquid so that the composition of the liquid changes continuously or intermittently during the synthetic process, wherein the obtained particles are oxides having a perovskite structure, the oxide having a perovskite structure is an oxide represented by ABO 3 , A represents at least one element selected from the group A consisting of barium, strontium, lead, rare-earth metals, magnesium, potassium, and sodium, and B represents at least one element selected from the group B consisting of titanium, zirconium, and niobium, at least a raw material comprising group-A element A 1 and a raw material comprising group-B element B 1 are incorporated in the liquid in advance before initiation of synthesis, the composition (1) comprises a raw material comprising another group-A element A 2 different from the A 1 element, and the raw material comprising element A 1 and the raw material comprising element B 1 are reacted and thereafter the composition (1) is supplied to the liquid and reacted in the synthesis process, and the particles having a composition of A 1 B 1 O 3 comprising the A 1 and B 1 elements as the principal components inside the particle and a composition of A 2 B 1 O 3 comprising the A 2 and B 1 elements as the principal components in the surface of the particle are obtained.