SYNTHESIS OF SOLID SOLUTION Ce_(1-x)Zr_xO_2 OF NANOMETER AT LOW TEMPERATURE

The solid solution Ce_(1-x)Zr_(x)O_(2) synthesized by conventional methods, in the range of 0.2x0.8, is usually composed of mixed phases. A series of Ce_(1-x)Zr_(x)O_(2) (x = 0—0.8) with single phase structure were successfully prepared at lower temperature by a modified polymer-network gel process. This synthetic route is unique and effective for the synthesis of mixed metal oxides, particularly those with metastable phase structures. The phase structure, morphology and grain size of the powders were measured by means of X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results show that the mean grain size of the products is within 10—20 nm and the unit cell volume presents a linear contraction with the increase of x value. Ce~(4+) is substituted for Zr~(4+ )in the lattice site while some stress still remains in it in cubic structure of solid solution Ce_(1-x)Zr_xO_2.