Abstract: The invention provides a process for the preparation of a bismuth sodium titanate (BNT) compound of formula (I) wherein A is one or more of Bi, Na, Li, K, Mg, Ca, Sr, Ba, La, Al, Cu, Eu, Ag and Zn; B is one or more of Ti, Nb, Ta, Zr, Fe, Nd, Eu and Co; 0<x<0.8; 0<y<0.8; and ?0.1<z<0.1; said process comprising spray pyrolysis of a solution comprising Bi ions, Na ions, Ti ions and, if present, metal (A) and/or metal (B) ions.

Abstract: The invention provides a ceramic composite oxide of formula (I): (1?x)AaBbOy+xCcDdOz (I) wherein A, B, C and D are each independently selected from the group consisting of Li, Na, Mg, Al, P, K, Ca, Sc, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Sr, Y, Zr, Nb, Mo, Ru, In, Sn, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Er, Tm, Yb, Lu, Ta, W, Bi and mixtures thereof; x is 0.05 to 0.95; y and z are balanced by the charge of the cations; 0?a, b, c, d?1; and wherein said ceramic composite oxide has an average particle size diameter of 10 to 700 nm.