Ab initio studies of magnetic anisotropy energy in highly Co-doped ZnO

Density functional theory (DFT) calculations of the energy of magnetic anisotropy for diluted magnetic semiconductor (Zn,Co)O were performed using OpenMX package with fully relativistic pseudopotentials. The analysis of the band spin-orbit interaction and the magnetic ion's surrounding on magnetic anisotropy have been provided. As a result, the calculations show that the magnetic anisotropy in (Zn,Co)O solid solution, mainly of the single ion anisotropy type has been caused by Co ions. •The magnetic anisotropy in (Zn,Co)O is mainly due to anisotropy of single cobalt ion.•The magnetic anisotropy of (Zn,Co)O strongly depends on the nearest neighborhood of magnetic ion including local lattice deformations.•For (Zn,Co)O the energy of magnetic anisotropy is described by second order terms in magnetization.