Stoner Ferromagnetism in Hole-Doped CuMIIIAO2 with MIIIA = Al, Ga, and In

Using density functional theory calculations, we examine the effect of hole doping on the magnetic and electronic properties of (CuMO2)-O-IIIA, with M-IIIA = Al, Ga, and In. (CuMO2)-O-IIIA nonmagnetic semiconductors switch to ferromagnetic half-metals upon hole doping. For CuAlO2, the nonmagnetic-to-ferromagnetic transition occurs for hole densities of similar to 7 x 10(19)/cm(3). Ferromagnetism arises from an exchange splitting of the electronic states at the valence band edge, and it can be attributed to the highlying Cu-d states. Hole doping induced by cation vacancies and substitutional divalent dopants is also investigated. Interestingly, both vacancies and nonmagnetic divalent dopants result in the emergence of ferromagnetism.