Using a first-principles method based upon density functional theory, a systematic investigation was made of the electronic structure and magnetic properties of N-doped ZnO, with and without Zn vacancies. The calculated results indicated that N-doped ZnO was a weak ferromagnet. Interestingly, the ferromagnetic stability could be increased significantly by doping a Zn vacancy. A Curie temperature of about 490K could be expected in N-doped ZnO with a Zn vacancy. The ferromagnetism in N-doped ZnO could be attributed to the hole-mediated double exchange interaction.

The Electronic Structures and Magnetic Properties of N-Doped ZnO with and without Zn Vacancy. Chen, Y.F., Song, Q.G., Yan, H.Y.: Computational and Theoretical Chemistry, 2012, 983, 65–8