Stabilization of Ferromagnetism in Co Codoped ZnO:N

First principle calculations were performed to study room temperature ferromagnetism in N doped ZnO (ZnO:N) using spin density functional theory. Substitution of O by N in ZnO results in spin polarized state exhibiting half metallic ferromagnetic characteristics. Each N dopant introduces magnetic moment of 1.0 mu(B)/supercell, which is from 2p electrons of N but the magnetization energy (Delta E = 14.42 meV) is too small to stabilize ferromagnetism at room temperature. Cobalt (Co) co-doping in ZnO:N is found to enhance ferromagnetism (magnetic moment = 4.24 mu(B)/supercell) with enhanced stability (Delta E = 635 meV) and is driven by hybridization between N 2p and Co 3d states.