A first principles study on the full-Heusler compound Mn2CuSi

Using a state-of-the-art full-potential electronic structure method within the generalized gradient approximation (GGA), we study the electronic structure and magnetic properties of the Mn₂CuSi full-Heusler alloy. Calculations show that CuHg₂Ti-type structure alloy is a half-metallic ferrimagnet with the Fermi level (ε_F) being located within a tiny gap of the minority-spin density of states. The conduction electron at ε_F keeps a 100% spin polarization. A total spin moment, which is mainly due to the antiparallel configurations of the Mn partial moments, is −1.00μ_B for a wide range of equilibrium lattice parameters. Simultaneously, the small spin magnetic moments of Cu and Si atoms are antiparallel. The gap mainly originates from the hybridization of the d states of the two Mn atoms. Thus, Mn₂CuSi may be the compound of choice for further experimental investigations.