Magnetic properties of nitrogen doped ZnO

Using the first principle method based on density functional theory, this paper studies the electronic structure and the ferromagnetic stability in N-doped ZnO. The calculated results based on local density approximation (LDA) and LDA+U method show that ferromagnetism coupling between N atoms is more energetically favourable for eight geometrically distinct configurations. The dominant ferromagnetic interaction is due to the hybridization between O 2p and N 2p. The origin of the ferromagnetic state in N doped ZnO is discussed by analysing coupling between N 2p levels. We also analyse N dopant concentration and lattice strain effect on ferromagnetism.