Geometric analysis of the grand potential and a calculation procedure of phase equilibria by CVM

摘要

Based on the definition of grand potential, a geometric method for obtaining a grand potential-effective chemical potential diagram from the relevant molar free energy diagram was proposed, and the effect of magnetic transition on grand potential was also discussed. It is shown that the grand potential and effective chemical potential in a ferromagnetic state can be separated into paramagnetic and magnetic terms. In addition, a hybrid calculation procedure of phase equilibria with magnetic transition based on CVM, combined with the geometric analysis was proposed and is applied to the alpha/gamma phase equilibrium in the Fe-Mn binary system. It is shown that this method is feasible.