Influence of Mn doping content on magnetic properties of a (Mn, N) co-doped ZnO system

In this paper, by investigating the magnetic properties of (Mn, N) co-doped ZnO films with various Mn doping contents, we found that the total magnetic moments of the samples would reach a limit under a certain N doping condition even if more Mn ions were incorporated into the ZnO lattice. Based on first-principles calculations, we propose that the unique magnetic interactions between Mn2+ dopants in the presence of nitrogen and the very low solubility of substitutional N relative to Mn in ZnO are responsible for the experimental observation.