First-Principles Calculation of Curie Temperature Tuning in <i>L</i>1₀-Type FePt by Element Substitution of Mn, Cu, Ru, and Rh

Abstract

We studied the Curie temperature T C variation in L1 0-type FePt ordered alloys that were partially substituted with other transition metal elements, such as Mn, Cu, Ru, and Rh, by first-principles calculations. For the theoretical evaluation of T C , a disordered local moment approach based on the coherent potential approximation was employed. The calculated results reveal that the most significant reduction in T C was observed for FePt where some Pt was substituted by Ru, while a large uniaxial magnetic anisotropy constant on the order of 10 7 erg/cm 3 was maintained. An analysis of the electronic structure demonstrates that the stability of the ferromagnetic state is degraded by the substitution of Ru.