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| Format: | Artículo científico |
| Language: | en |
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Sociedade Brasileira de Física
2006
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| Online Access: | https://www.redalyc.org/articulo.oa?id=46436504 |
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Table of Contents:
- Effects of Disorder on the Exchange coupling in (Ga,Mn)As Diluted Magnetic Semiconductors A. Fazzio Antônio J. R. da Silva Raimundo R. dos Santos Luiz E. Oliveira Física, Astronomía y Matemáticas Disorder Exchange coupling Diluted magnetic semiconductors A theoretical study of the effects of disorder on the Mn-Mn exchange interactions for Ga1¡xMnxAs dilutedmagnetic semiconductors is presented. The disorder is intrinsically considered in the calculations, which areperformed using an ab initio total energy density-functional approach, for a 128 atoms supercell, and by consideringa variety of configurations with 2, 3 and 4 Mn atoms. Results are obtained for the effective JMn¡Mnn , fromfirst (n = 1) all the way up to sixth (n = 6) neighbors via a Heisenberg Hamiltonian used to map the magneticexcitations from ab initio total energy calculations. One then obtains a clear dependence in the magnitudes ofthe JMn¡Mnn with the Mn concentration x. Moreover, we show that, in the case of fixed Mn concentration, configurationaldisorder and/or clustering effects lead to large dispersions in the Mn-Mn exchange interactions. Also,calculations for the ground-state total energies for several configurations suggest that a proper consideration ofdisorder is needed when one is interested in treating temperature and annealing effects. 2006 artículo científico 0103-9733 https://www.redalyc.org/articulo.oa?id=46436504 en http://www.redalyc.org/revista.oa?id=464 Brazilian Journal of Physics application/pdf Sociedade Brasileira de Física Brazilian Journal of Physics (Brasil) Num.3B Vol.36