Determination of standard entropy of formation of Al11Nd3 by heat capacity measurement from near absolute zero Kelvin

The thermodynamic properties of Al11Nd3 were investigated by measuring the heat capacities, Cp, from near absolute zero (2 K) to 300 K by the relaxation method. In the low temperature range of 2–15 K, three λ-type thermal anomalies were found. The third law entropy of Al11Nd3(Al0.786Nd0.214) at 298 K was obtained by the integration of polynomials for measured Cp. The result was as follows:S298(Al0.786Nd0.214) (J K−1 mol−1)=−35.12±0.35.S298(Al0.786Nd0.214) (J K−1 mol−1)=−35.12±0.35.Using this value, the entropy of mixing and the standard entropy of formation at 298 K were obtained as follows:ΔmixS298(Al0.786Nd0.214) (J K−1 mol−1)=−2.32±0.39,  ΔfS298°(Al11Nd3) (J K−1 mol−1)=−32.5±5.5.