The thermodynamic properties of the magnetic phase transition from ferro- to para-phases of AlNd2 were directly investigated by using calorimetry. The standard entropies of formation Delta S-f degrees(m,T), of the ferro- and paramagnetic phases were determined by measuring the heat capacity, C degrees(p,m), from 2 to 300 K. The standard enthalpies of formation, Delta H-f degrees(m,T), of them were determined by combining C degrees(p,m) with the standard enthalpy of formation, Delta H-f degrees(m,298), at 298 K obtained by acid solution calorimetry. The standard Gibbs energies of formation. Delta(f)G degrees(m,T), of the Ferro- and paramagnetic phases of AlNd2 were determined from their Delta S-f degrees(m,T) and Delta H-f degrees(m,T) values. The Delta(f)G degrees(m,T) values indicate that the magnetic phase transition from ferro- to paramagnetic phases occurs at 39.59 K, consistent with the observed phase transition at 39.59 K. (C) 2011 Elsevier B.V. All rights reserved.