Synthesis of nanometer-scale solid solution Ce_1-xZr_xO₂ by polymer-network gel and their thermal stability

The solid solution Ce_1-xZr_xO₂ were successfully synthesized by a modified polymer-network gel process at low temperature. In the ranges of 0≤x≤0.6 and 0.7≤x≤0.9, the solid solutions posses a cubic and a tetragonal phase structure respectively. As for x=l.0, the product is composed of tetragonal and monoclinic phases. The analysis with transmission electron microscopy (TEM) shows that the mean grain size of the solid solutions is within 10-20 nm. The calculated results indicate that the unit cell volume present a linear contraction with the increase of Zr contents. It can be inferred from the results of differential scanning calorimetry (DSC) and XRD that within the scope of 0≤x≤0.9, the crystal symmetry of Ce_1-xZr_xO₂ remains stable between 323 K and 1273 K.