Bulk thermal expansion studies of Th1−xCexO2 in the complete solid solution range

ThO2 and CeO2 are shown to form an almost ideal solid solution throughout the homogeneity range. Bulk thermal expansion studies on Th1−xCexO2 (0.0⩽x⩽1.0) were carried out by dilatometry from 293 to 1123 K in air. The average linear thermal expansion coefficients, ᾱ, of ThO2 and CeO2 were found to be 9.04×10−6 and 11.58×10−6 K−1, respectively, between 293 and 1123 K. The substitution of Ce4+ at Th4+ sites in ThO2 induced a systematic upward trend in the thermal expansion behavior throughout this series of solid solution on going from ThO2 to CeO2.