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

Georges Bouzerar·Timothy Ziman·Josef Kudrnovsky
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Abstract

We present a semi-analytic theory for the Curie temperature in diluted magnetic semi-conductors 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 {\it ab initio} estimates. The theory gives very good agreement with published data for well-annealed samples of Mn$_x$Ga$_{1-x}$As. We predict the critical temperatures for Mn$_x$Ga$_{1-x}$N lower than in doped GaAs, despite the stronger nearest-neighbour ferromagnetic coupling. We also predict the dependence on the hole concentration.

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Georges Bouzerar, Timothy Ziman, Josef Kudrnovsky. 2004-05-14. Calculating the Curie Temperature reliably in diluted III-V ferromagnetic semiconductors. https://doi.org/10.1209/epl%2Fi2004-10473-1

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