Half-metallic ferromagnetism in TM-doped MgH2 hydride

We show that, in addition to its thermodynamic properties that make it a good candidate for hydrogen storage, the MgH 2 hydride exhibits interesting magnetic properties when doped with some transition metals (TM). Using the Korringa–Kohn–Rostoker method (KKR) combined with the coherent potential approximation in the framework of first-principle calculations, we study the half-metallic ferromagnetic properties of the MgH 2 doped with TM: Co, V, Cr, Ti; Mg 0.95 TM 0.05 H 2 . The ferromagnetic state energy is computed and compared with the disordered local moment state energy. We show, from the electronic structure, that doping MgH 2 with TM elements can convert the material to a half-metallic with a high wide impurity band and high magnetic moment. We have found that the corresponding Curie temperature is bigger than the room temperature, which is considered as a relevant parameter for spintronic applications. Moreover, the mechanism of the hybridization and the interaction between the magnetic ions are also investigated showing that the double exchange is the underlying mechanism responsible for the magnetism of such materials .