Ab-initio Study of the Magnetic Properties of (Mn_0.75X_0.25)AlGe (X = V, Cr, Mn, Fe)

Abstract

The effect of the substitution of V, Cr, and Fe on the magnetic properties of MnAlGe ternary compounds has been investigated by first-principles electronic calculations. The total energy differences (ΔEs) between the ferromagnetic and nonmagnetic states varied in a similar trend to the variation in their experimental Curie temperatures. Thus, ΔE can be used to make an approximate and systematic estimation of the effect that atomic substitution or the addition of a fourth element will have on the Curie temperature. The results show that the magnetization of MnAlGe compounds (or the magnetic moment of Mn) is sensitive to the variation of the distance between the Mn layer and its adjacent layer comprising Al and Ge atoms. A large distance between the layers corresponds to a large magnitude of magnetization.