Electronic and magnetic structure of transition-metal-doped α-hematite -: art. no. 205208

We investigate the electronic and magnetic structure of transition-metal-doped a-hematite using the local density approximation with local correlations (LDA+U). The dopants in this study are the 3d transition metals Sc-Zn and Ga and are assumed to substitute on an Fe site. The calculated net moment per substitutional impurity is found to be vertical bar z(D)-z(Fe)vertical bar, opposite to that of the replaced Fe, where Z(D) and z(Fe) are the numbers of valence electrons of the dopant and Fe, respectively. The dopants, D, substitute in an effective charged state D3+ except for Ti4+ and Zn2+. In the case of Ti, the extra electron converts a neighboring Fe3+ atom to Fe2+. In the case of Zn, the missing electron generates a relatively diffuse hole at the top of the valence band spread over neighboring O atoms.