Patent ID: 8329129

Claim:
A method for preparing a pyrochlore oxide represented by A 2 B 2 O 7-Z wherein A and B each represent a metal element, Z satisfies the formula 0≦Z≦1, A comprises A 1 that is at least one selected from the group consisting of Pb, Sn, and Zn, and B comprises B 1 that is at least one selected from the group consisting of Ru, W, Mo, Ir, Rh, Mn, Cr, and Re, the method comprising: preparing a first aqueous solution that is an aqueous solution of the halide or nitrate of said A, and a second aqueous solution that is an aqueous solution of the alkali salt of a metal acid of said B; and dropwise delivering one of the first aqueous solution and the second aqueous solution into the other of the first aqueous solution and the second aqueous solution to carry out the reaction to form a precipitate of the pyrochlore oxide, wherein the pyrochlore oxide is formed on an electrically conductive material by dispersing the electrically conductive material in either one of the first aqueous solution and the second aqueous solution, and thereafter carrying out said dropwise delivering.