Hostname: page-component-77c89778f8-5wvtr Total loading time: 0 Render date: 2024-07-20T16:18:48.093Z Has data issue: false hasContentIssue false

Hole concentration vs. Mn fraction in a diluted (Ga,Mn)As ferromagnetic semiconductor

Published online by Cambridge University Press:  21 March 2011

Raimundo R. dos Santos
Affiliation:
Inst. de Física, Univ. Fed. do Rio de Janeiro, CP 68.528, Rio de Janeiro–RJ, 21945-970, Brazil
L. E. Oliveira
Affiliation:
Instituto de Física, Unicamp, CP 6165, Campinas-SP, 13083-970, Brazil
J. d'Albuquerque e Castro
Affiliation:
Inst. de Física, Univ. Fed. do Rio de Janeiro, CP 68.528, Rio de Janeiro–RJ, 21945-970, Brazil
Get access

Abstract

The dependence of the hole density on that of Mn sites in Ga1−xMnxAs is studied within a mean-field approach to the hole-mediated ferromagnetism in III-V Mn-based semiconductor compounds. We parametrize the hole concentration, p, as a function of the fraction of Mn sites, x, in terms of the product m* (Jpd)2 (where m* is the hole effective mass and Jpd is the Kondo-like hole/local-moment coupling), and the critical temperature Tc. By fitting m* (Jpd)2 to experimental data for Tc(x), we establish the dependence of p on x, which is interpreted in terms of a reentrant metal-insulator transition taking place in the hole gas.

Type
Research Article
Copyright
Copyright © Materials Research Society 2002

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Ohno, H., Munekata, H., Penney, T., von Molnàr, S., and Chang, L. L., Phys. Rev. Lett. 68, 2664 (1992).Google Scholar
2. Ohno, H., Shen, A., Matsukura, F., Oiwa, A., Endo, A., Katsumoto, S., and Iye, Y., Appl. Phys. Lett. 69, 363 (1996).Google Scholar
3. Ohno, H., Science 281, 951 (1998); R. Flederling, M. Kelm, G. Reuscher, W. Ossau, G. Schmidt, A. Waag, and L. W. Molenkamp, Nature 402, 787 (1999); Y. Ohno, D. K. Young, B. Beschoten, F. Matsukura, H. Ohno, and D. D. Awschalom, Nature 402, 790 (1999); H. Ohno, J. Magn. Magn. Mater. 200, 110 (1999); T. Dietl, H. Ohno, F. Matsukura, J. Cibert, and D. Ferrand, Science 287, 1019 (2000).Google Scholar
4. DiVincenzo, D. P., J. Appl. Phys. 85, 4785 (1999).Google Scholar
5. Hayashi, T., Tanaka, M., and Nishinaga, T., J. Appl. Phys. 81, 4865 (1997).Google Scholar
6. Ohno, H. and Matsukura, F., Solid State Commun. 117, 179 (2001).Google Scholar
7. Matsukura, F., Ohno, H., Shen, A., Sugawara, Y., Phys. Rev. B57, R2037 (1998).Google Scholar
8. Szczytko, J., Mac, W., Twardowski, A., Matsukura, F., and Ohno, H., Phys. Rev. B 59, 12935 (1999).Google Scholar
9. Dietl, T., Ohno, H., and Matsukura, F., Phys. Rev. B 63, 195205 (2001).Google Scholar
10. Look, D. C., J. Appl. Phys. 70, 3148 (1991).Google Scholar
11. Van Esch, A., Van Bockstal, L., De Boeck, J., Verbanck, G., van Steenbergen, A. S., Wellmann, P. J., Grietens, B., Bogaerts, R., Herlach, F., and Borghs, G., Phys. Rev. B 56, 13103 (1997).Google Scholar
12. Dietl, T., Haury, A., and d'Aubigné, Y. Merle, Phys. Rev. B55, R3347 (1997).Google Scholar
13. Jungwirth, T., Atkinson, W. A., Lee, B. H., and MacDonald, A. H., Phys. Rev. B 59, 9818 (1999).Google Scholar
14. Lee, B., Jungwirth, T., and MacDonald, A. H., Phys. Rev. B 61, 15606 (2000).Google Scholar
15. Hong, S. P., Yi, K. S., and Quinn, J. J., Phys. Rev. B 61, 13745 (2000).Google Scholar
16. Konig, J., Lin, H.-H., and MacDonald, A. H., cond-mat/0010471.Google Scholar
17. Litvinov, V. I. and Dugaev, V. K., Phys. Rev. Lett. 86, 5593 (2001).Google Scholar
18. Abolfath, M., Jungwirth, T., Brum, J., and MacDonald, A. H., Phys. Rev. B 63, 054418 (2001).Google Scholar
19. Ohno, H., Matsukura, F., Omiya, T., and Akiba, N., J. Appl. Phys. 85, 4277 (1999).Google Scholar
20. The currently accepted value p = 3.5 × 1020 cm−3 is a factor 2.3 larger than the early estimate; see Ref. 3.Google Scholar
21. See, e.g., Fig. 2 of Ref. 7: for x = 0.022, the experimentally determined p has an error bar which covers over one decade, while for x = 0.071 the error bar runs over two decades.Google Scholar
22. For a treatment of the same model within spin-wave theory and dynamical mean-field theory, see Konig, J., Lin, H.-H., and H.MacDonald, A., Phys. Rev. Lett. 84, 5628 (2000); J. Konig, H.-H. Lin, and A. H.MacDonald, Phys. Rev. Lett. 86, 5637 (2001), and A. Chattopadhyay, S. Das Sarma, and A. J. Millis, condmat/ 0106455. The explicit dependence of p with x, however, is not discussed in those works.Google Scholar