Europhys. Lett.
Volume 69, Number 5, March 2005
Page(s) 812 - 818
Section Condensed matter: electronic structure, electrical, magnetic, and optical properties
Published online 16 February 2005
Europhys. Lett., 69 (5), pp. 812-818 (2005)
DOI: 10.1209/epl/i2004-10473-1

Calculating the Curie temperature reliably in diluted III-V ferromagnetic semiconductors

G. Bouzerar1, T. Ziman1 and J. Kudrnovský2

1  Institut Laue Langevin - BP 156, 38042 Grenoble, France
2  Institute of Physics, Academy of Sciences of the Czech Republic Na Slovance 2, CZ-182 21 Prague 8, Czech Republic

received 17 December 2004; accepted in final form 14 February 2005
published online 16 February 2005

We present a semi-analytic theory for the Curie temperature in diluted magnetic semiconductors that treats disorder effects exactly in the effective Heisenberg Hamiltonian, and spin fluctuations within a local RPA. The exchange couplings are taken from concentration-dependent ab initio estimates. The theory gives very good agreement with published data for well-annealed samples of MnxGa1-xAs. We predict that critical temperatures for strongly p-type MnxGa1-xN would be lower than in doped GaAs, despite the stronger nearest-neighbour ferromagnetic coupling. We also predict the dependence on the hole concentration.

75.50.Pp - Magnetic semiconductors.
75.47.-m - Magnetotransport phenomena; materials for magnetotransport.
71.55.Eq - III-V semiconductors.

© EDP Sciences 2005