Thermodynamic and mechanical properties of Ce1−xHfxO2 (x=0–0.10) solid solutions

Thermal expansion and mechanical properties of Ce1−xHfxO2 (x=0–0.10) solid solutions were measured from 100 to 850 K by TMA and from 180 to 303 K by ultrasonic pulse methods, as a function of temperature and hafnium concentration. Using these measured values and reported specific heat capacities (Cp) at 298.15 K, Grüneisen parameters (γ) of Ce1−xHfxO2 were calculated from the thermodynamic relation γ=3αVKa/Cp. Then heat capacities Cp of Ce1−xHfxO2 (x=0–0.10) at temperatures from 150 to 800 K were calculated by using the equation Cp=3αVKa/γ. The calculated Cp of undoped CeO2 was in reasonable agreement with the reported value over a wide temperature range. Thus, it seems to be reasonable to derive heat capacities of Ce1−xHfxO2 solid solutions as well as CeO2 by using this method.