Electronic structure and magnetic properties of (Mn, N)-codoped ZnO

The electronic structures and magnetic properties of (Mn, N)-codoped ZnO are investigated by using the first-principles calculations. In the ferromagnetic state, as N substitutes for the intermediate O atom of the nearest neighboring Mn ions, about 0.5 electron per Mn²⁺ ion transfers to the N^2- ion, which leads to the high-state Mn ions (close to +2.5) and trivalent N^3- ions. In an antiferromagnetic state, one electron transfers to the N^2- ion from the downspin Mn²⁺ ion, while no electron transfer occurs for the upspin Mn²⁺ ion. The (Mn, N)-codoped ZnO system shows ferromagnetism, which is attributed to the hybridization between Mn 3d and N 2p orbitals.