Tunable electrical and magnetic properties of half-metallic ZnxFe3-xO4 from first principles

The electrical and magnetic properties of Zn-doped Fe3O4 at different doping concentrations of Zn have been investigated using a density functional method with generalized-gradient approximation corrected for on-site Coulombic interactions. The electronic structure calculation predicts that ZnxFe3-xO4 (0 <= x <= 0.875) is half-metallic with a full spin polarization. The hopping carrier concentration of ZnxFe3-xO4 decreases with increasing x, which indicates a distinct increase in the resistivity. The saturation magnetization of ZnxFe3-xO4 increases evidently with increasing x from x = 0 to x = 0.75 (i.e. from 4.0 to 8.3 mu(B)/f.u.) and then decreases rapidly to zero at x = 1. The robust half-metallicity, large tunability of electrical and magnetic properties of a Zn doped Fe3O4 system make it a promising functional material for spintronic applications.