中国物理B ›› 2011, Vol. 20 ›› Issue (8): 86601-086601.doi: 10.1088/1674-1056/20/8/086601

• CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES • 上一篇    下一篇

Magnetic properties of Mn-doped GaN with defects: ab-initio calculations

E. Salmani1, A. Benyoussef1, H. Ez-Zahraouy1, E. H. Saidi2   

  1. (1)LMPHE, Departement de Physique, Faculté des Sciences, Université Mohammed V-Agdal, Rabat, Morocco; (2)LPHE, Departement de Physique, Faculté des Sciences, Université Mohammed V-Agdal, Rabat, Morocco
  • 收稿日期:2010-10-24 修回日期:2011-04-19 出版日期:2011-08-15 发布日期:2011-08-15

Magnetic properties of Mn-doped GaN with defects: ab-initio calculations

E. Salmania), A. Benyoussefa), H. Ez-Zahraouya)†, and E.H. Saidib)   

  1. a LMPHE, Departement de Physique, Faculté des Sciences, Université Mohammed V-Agdal, Rabat, Morocco; b LPHE, Departement de Physique, Faculté des Sciences, Université Mohammed V-Agdal, Rabat, Morocco
  • Received:2010-10-24 Revised:2011-04-19 Online:2011-08-15 Published:2011-08-15

摘要: According to first-principles density functional calculations, we have investigated the magnetic properties of Mn-doped GaN with defects, Ga1-x-yVGxMny N1-z-tVNzOt with Mn substituted at Ga sites, nitrogen vacancies VN, gallium vacancies VG and oxygen substituted at nitrogen sites. The magnetic interaction in Mn-doped GaN favours the ferromagnetic coupling via the double exchange mechanism. The ground state is found to be well described by a model based on a Mn3+—d5 in a high spin state coupled via a double exchange to a partially delocalized hole accommodated in the 2p states of neighbouring nitrogen ions. The effect of defects on ferromagnetic coupling is investigated. It is found that in the presence of donor defects, such as oxygen substituted at nitrogen sites, nitrogen vacancy antiferromagnetic interactions appear, while in the case of Ga vacancies, the interactions remain ferromagnetic; in the case of acceptor defects like Mg and Zn codoping, ferromagnetism is stabilized. The formation energies of these defects are computed. Furthermore, the half-metallic behaviours appear in some studied compounds.

Abstract: According to first-principles density functional calculations, we have investigated the magnetic properties of Mn-doped GaN with defects, Ga1-x-yVGxMny N1-z-tVNzOt with Mn substituted at Ga sites, nitrogen vacancies VN, gallium vacancies VG and oxygen substituted at nitrogen sites. The magnetic interaction in Mn-doped GaN favours the ferromagnetic coupling via the double exchange mechanism. The ground state is found to be well described by a model based on a Mn3+—d5 in a high spin state coupled via a double exchange to a partially delocalized hole accommodated in the 2p states of neighbouring nitrogen ions. The effect of defects on ferromagnetic coupling is investigated. It is found that in the presence of donor defects, such as oxygen substituted at nitrogen sites, nitrogen vacancy antiferromagnetic interactions appear, while in the case of Ga vacancies, the interactions remain ferromagnetic; in the case of acceptor defects like Mg and Zn codoping, ferromagnetism is stabilized. The formation energies of these defects are computed. Furthermore, the half-metallic behaviours appear in some studied compounds.

Key words: diluted magnetic semiconductor, GaN:Mn, defects, ab-initio, magnetic properties

中图分类号:  (Thermal diffusivity)

  • 66.30.Xj
72.20.Dp (General theory, scattering mechanisms) 72.20.My (Galvanomagnetic and other magnetotransport effects) 72.25.Dc (Spin polarized transport in semiconductors)