Ferromagnetism in p-type AlN crystals doped with carbon from
Ab initio study
Liang Xu, Xiang Zhai and Ling-Ling Wang*
Key Laboratory for Micro-Nano Optoelectronic Devices of Ministry of Education,
Hunan University, Changsha, hunan, China
School of Physics and Microelectronics, Hunan University, Changsha, Hunan, China
Ab initio spin-polarized density functional theory calculations[1,2] are performed to
investigate p-type C-doped AlN crystals with wurtzite structure as a possible dilute magnetic
semiconductor. Our calculations predict halt-metallic ferromagnetism in C doped AlN, resulting
from carbon substitution of nitrogen. A single carbon substitution of nitrogen favors a
spin-polarized state with a magnetic moments of 1.0 µB. The ferromagnetism ground state in
C-doped AlN can be explained by the p-d exchange-like p-p coupling interaction which is
derived from the impurity and valence states[3,4], and a Curie temperature around 400 K can be
expected. We also propose a co-doping method with C acceptor and O donor in AlN:[2C + O],
to enhance the ferromagnetic coupling and p-type conductivity. These results suggest that
C-doped AlN may present a new p-type dilute magnetic semiconductor and find applications in
the field of spintronics.
[1] G. Kresse and H. Hafner. Phys. Rev. B47, 558 (1993); 48, 13115 (1994).
[2] G. Kresse and J. Furthmuller. Comput. Mater. Sci. 6, 15 (1996).
[3] H. Pan et al. Phys. Rev. Lett. 99, 127201(2007).
[4] Hui Pan and Yuan Ping Feng. Phys. Rev. B77, 125211 (2008).
*
Electronic mail: llwang@hnu.cn