Thermodynamic properties of Ce3In were determined using low-temperature thermal relaxation calorimetry, high-temperature differential scanning calorimetry, high-temperature gallium melt drop solution calorimetry, and density functional theory (DFT) calculations. At low temperatures, the electronic and phononic terms to the specific heat are: γ = 53(1) mJ·mol−1·K2, \({\Theta }_{D1}\) = 174(2) K, \({\Theta }_{D2}\) = 68(3) K. The standard entropy ( \(S^\circ\) ) and the standard entropy of formation from the elements (ΔSf,298.15 K) are 55.8 ± 1.5 J·mol−1·atom−1·K−1 and − 10.8 ± 1.7 J·mol−1 ·atom−1·K−1, respectively. The standard enthalpy of formation from the elements (ΔHf,298.15 K) is − 35.44 ± 8.95 kJ·mol−1·atom−1 from calorimetric measurements, as compared with ΔHf,0 K, Dudarev = − 30.735 kJ·mol−1·atom−1 and ΔHf,0 K, Liechtenstein = − 31.474 kJ·mol−1·atom−1 based on DFT + U. Using these parameters, the Gibbs energy of formation (ΔGf,298.15 K) is derived to be − 32.2 ± 8.9 kJ·mol−1·atom−1. These thermodynamic values of Ce3In can serve as input parameters in modeling its phase stability relations with other Ce–M–In compounds.
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