Magnetism of Cr-doped ZnO with intrinsic defects

The electronic structure and formation energies of defect in Cr-doped ZnO are investigated by the first-principles calculations. The dopant Cr atom and native defects (O vacancy, Zn vacancy, and Zn interstitial) at different charge states are considered. The calculated results indicate that the substitutive Cr in the oxidation state of +3 and the neutral Zn vacancy in the ZnO: Cr sample is the most favorable defect complex to maintain a high stability of ferromagnetic order. Therefore, a p-type ZnO: Cr prepared under O-rich condition could have a higher Curie temperature. The p-d hybridization and the itinerant d-characteristic n-type carriers are suggested to mediate the long range ferromagnetic exchange interaction between Cr atoms. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4727951]