Electronic and magnetic properties of MnN versus MnAs

Electronic and magnetic properties of MnN and MnAs compounds in the hypothetical cubic zinc-blende phase are studied using first-principles band structure method. We show that the high electronegativity and small atomic size of N compared to As lead to interesting consequences: MnN has a low-spin antiferromagnetic ground state, whereas MnAs has a high-spin hole mediated ferromagnetic (FM) ground state. Because the Mn d bands are higher in energy than the N p band, Mn is not efficient to generate free holes in the nitrides. Therefore, previous prediction that undoped Ga1−xMnxN diluted alloy can result in room-temperature FM semiconductor should be reexamined.