Acta Phys. -Chim. Sin. ›› 2010, Vol. 26 ›› Issue (10): 2801-2806.doi: 10.3866/PKU.WHXB20101021

• QUANTUM CHEMISTRY AND COMPUTATION CHEMISTRY • Previous Articles     Next Articles

Half-Metallic Properties of Mn-AlN and Cr-AlN Based on First-Principles

FAN Yu-Qin1, HE A-Ling2   

  1. 1. College of Mathematics and Physics, Chongqing University of Science and Technology, Chongqing 401331, P. R. China;
    2. College of Physics, Chongqing University, Chongqing 400044, P. R. China
  • Received:2010-04-15 Revised:2010-06-29 Published:2010-09-27
  • Contact: FAN Yu-Qin E-mail:g.y.wind@163.com
  • Supported by:

    The project was supported by the Chongqing Natural Science Foundation, China (CSTC -2007BB4137).

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Abstract:

The band structures, density of states (DOS), and magnetic properties of wurtzite Mn-AlN and Cr-AlN were studied using density functional theory (DFT) with the generalized gradient approximation (GGA) for the exchange-correlation potential. The results indicate that the half-metallic gap of Mn-AlN and Cr-AlN decreases as the Mn/Cr doping concentration increases. This probably results froman increase in the interaction between Mn and Mn or Cr and Cr atoms and a decrease in the hybridization of Mn/Cr 3d and N 2p states with increasing the Mn/Cr doping concentration, which results in a smaller spin-exchange splitting so the half-metallic gap is reduced. Additionally, with the same doping concentration, the half-metallic gap of Mn-AlN is larger than that of Cr-AlN. This is due to the lower Mn 3d states compared to the Cr 3d states and the hybridization of Mn 3d and N 2p states being stronger in Mn-AlN, which leads to a larger spin-exchange splitting so the conduction band minimum of the down spin bands moves far away fromthe Fermi level and the half-metallic gap of Mn-AlN becomes larger.

Key words: AlN, Transition metal doping, Half-metal, Band structure, State density