The influence of oxygen vacancy on the magnetism of Co-doped ZnO was investigated by the first-principles calculations. It was suggested that oxygen vacancy and its location played crucial roles on the magnetic properties of Co-doped ZnO. The exchange coupling mechanism should account for the magnetism in Co-doped ZnO with oxygen vacancy and the oxygen vacancy was likely to be close to the Co atom. The oxygen vacancy (doping electrons) might be available for carrier mediation but was localized with a certain length and could strengthen the ferromagnetic exchange interaction between Co atoms.

Effect of Oxygen Vacancy Defect on the Magnetic Properties of Co-Doped ZnO. Z.Z.Weng, J.M.Zhang, Z.G.Huang, W.X.Lin: Chinese Physics B, 2011, 20[2], 027103