Phase stability determination of the Mg-B binary system using the CALPHAD method and ab initio calculations

Knowledge of the Mg-B binary phase diagram is important in for the synthesis of superconducting MgB2 and of potential, new Mg-B alloys. However, the literature phase diagram is highly uncertain because it was originally constructed by guessing the decomposition temperatures of magnesium boride phases. We therefore utilized the CALPHAD method and ab initio calculations to compute thermodynamic model parameters to determine the decomposition temperatures of magnesium borides and re-assess the Mg-B binary phase diagram.