Based on our first-principle calculations, ZnO doped by a nonmagnetic $2p$ light element (N) is predicted to be ferromagnetic. The local magnetic moments that are mainly localized on doped N atoms introduced total moments of $1.0{\mu }_B/\text{atom}$. The long-range magnetic coupling of N-doped ZnO can be attributed to a $p\text{−}d$ exchange-like $p\text{−}p$ coupling interaction involving holes, which is derived from the similar symmetry and wave function between the impurity ($p$-like $t_2$) and valence $\left(p\right)$ states. We also propose a codoping mechanism, using beryllium and nitrogen as dopants in ZnO, to enhance the ferromagnetic coupling and to increase the solubility and activity.

• Received 22 May 2008

DOI:https://doi.org/10.1103/PhysRevB.78.073306