A comprehensive assessment of the low-temperature thermal properties and thermodynamic functions of CeO₂

Reported is an experimental and computational investigation of the low temperature heat capacity, thermodynamic functions, and thermal conductivity of stoichiometric, polycrystalline CeO₂. The experimentally measured heat capacity at T < 15 K provides an important correction to the historically accepted experimental values, and the low temperature thermal conductivity serves as the most comprehensive data set at T < 400 K available. Below 10 K, the heat capacity is observed to obey the Debye T³ law, with a Debye temperature of Θ_D = 455 K. The entropy, enthalpy, and Gibbs free energy functions are obtained from the experimental heat capacity and compared with predictions from Hubbard-corrected density functional perturbation theory calculations using the Perdew, Burke, and Ernzerhof parameterization revised for solids. The thermal conductivity is determined using the Maldonado continuous measurement technique, along with laser flash analysis, and analyzed according to the Klemens-Callaway model.