Proposed calculation method for structural formation enthalpy including magnetic energy for transition metal alloys

Taking into account the contribution of magnetic energy, the lattice stability curves, i.e., the correlation between lattice energy and valence electron number, of 3-5d transition metals are constructed, and the stable structures of the ferromagnetic elements of Fe, Co and Ni being bcc, hcp and fcc, respectively, are confirmed. On the basis of calculated lattice stabilities and after further consideration of the orbital energy contributed from the valence electrons, a calculation method is proposed for calculating the structural formation enthalpy of 3-5d transition metal alloys. It is shown that the proposed calculation method is able to predict the correct structure-composition correlation over an entire composition range of the alloy systems consisting of 3-5d transition metals, e.g., in the Co-Ni, Ru-Rh and Ir-Os systems as representatives.