Thermodynamic analysis of phase equilibria in the Mn-Bi-Sb ternary system

A thermodynamic analysis of phase equilibria in the Mn-Bi-Sb ternary system has been carried out with specially focusing on the stability of the ferromagnetic NiAs-type αMnBi phase by an addition of Sb. In this study, the Gibbs free energy of this phase was evaluated using first-principles calculations combined with the cluster variation method (CVM), and the obtained results as well as the available experimental data on phase boundaries and thermodynamic properties were introduced in the analysis. The calculated results enabled the reproduction of experimental results on both the phase equilibria and thermodynamic properties obtained from first-principles calculations and the CVM. The calculations indicated that the stable region of NiAs-type αMnBi phase is expanded with increasing Sb content in alloys.