Magnetism in Ni-doped AlN with N vacancy: A first-principles study

We carried out first-principles calculations in order to provide comprehensive information regarding the nitrogen vacancy effects (NV) on the magnetism of NixAl1−xN(x = 0.028) system. It has been found that the system is energetically more favorable for single Ni doping in Al site with one N-vacancy when compared to single Ni doping configuration. The present calculation reveals a stable ferromagnetism in Ni-doped wurtzite AlN with a magnetic moment of 3.00 μ B for 2.8% of Ni doping. When Ni is substituted in Al site with N-vacancy the system becomes half-metallic. The N-vacancy induced defects also show a lower magnetic moment than 3.00 μ B , which is in good agreement with the experimental observations. The results indicate that magnetic moment is reduced by the weak 3d–3d spin coupling due to the long range hybridization between Ni-3d and N defect states.