| abstract |
In the gas phase production method of a metal oxide which oxidizes a metal halide to an oxidizing gas at high temperature, at least two or more compounds having different metal elements selected from the group consisting of chlorides, bromide and iodide of titanium, silicon and aluminum are selected. As a mixed gas (mixed metal halide gas) to be contained, the mixed metal halide gas and oxidizing gas are preheated to 500 ° C. or higher and reacted, respectively, to have a BET specific surface area of 10 to 200 m 2 / g and primary particles in a mixed crystal state. A method for producing an ultra-fine particle mixed crystal oxide, characterized by producing an ultra-fine particle oxide containing, and the use of the ultra-fine particle oxide obtained by the method and the oxide. |