| In recent years, research found that transition metal doped oxides and nitrides could produce room temperature ferromagnetism. But the magnetic clusters magnetic deposition or second equal may be formed when the magnetic element doped oxides and nitrides. To avoid these non-magnetic in good faith, people began to study with high magnetic transition temperature of the non-magnetic doped semiconductors. The first main group elements, non-magnetic elements, and AlN is an important semiconductor material. In this paper Li, Na and K doped AlN system, the electronic structure and magnetic properties were analyzed. We have made GGA + U amendment in the associated with N-ion p orbital effect in calculation. GGA and GGA + U calculations show that the pure AlN is not magnetic, in Li, Na and K doped AlN, alternative to Al, Li, Na and K atoms all produced 2.0μB magnetic moment, magnetic moment mainly from the doping atoms neighboring N atom 2p orbital, doping atoms also provides a small moment, in which Li and Na atoms in the magnetic moment of the main track from their p, K the magnetic moment mainly comes from The 3p and 3d orbit. The contribution of Al atoms on the magnetic properties can be ignored. Compared to the results of GGA calculations, U correction makes the magnetic distribution near N atom more concentrated in the vicinity of doped atoms. The magnetic coupling calculations have shown Li, Na and K doped AlN are ferromagnetic ground state, indicating that ferromagnetism could be produced after Li, Na, K doped AlN which does not have magnetic. This could provide a new material for the development of new magnetic semiconductors. Since magnetic moment arising mainly from the doping atoms neighboring N atoms, by the overlap of N atoms produced a spin-polarized long-range ferromagnetic coupling. The study will not only help improve the magnetic exchange interaction theory, and also provide new theoretical predictions and guidance for the designed of experimental spin-electronic devices.
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