تقرير
Phase diagram and critical behavior of the random ferromagnet $Ga_{1-x}Mn_xN$
| العنوان: | Phase diagram and critical behavior of the random ferromagnet $Ga_{1-x}Mn_xN$ |
|---|---|
| المؤلفون: | Stefanowicz, S., Kunert, G., Simserides, C., Majewski, J. A., Stefanowicz, W., Kruse, C., Figge, S., Li, Tian, Jakiela, R., Trohidou, K. N., Bonanni, A., Hommel, D., Sawicki, M., Dietl, T. |
| المصدر: | Phys. Rev. B 88, 081201(R) (2013) |
| سنة النشر: | 2013 |
| المجموعة: | Condensed Matter |
| مصطلحات موضوعية: | Condensed Matter - Disordered Systems and Neural Networks, Condensed Matter - Materials Science |
| الوصف: | Molecular beam epitaxy has been employed to obtain Ga1-xMnxN films with x up to 10% and Curie temperatures T_C up to 13 K. The magnitudes of T_C and their dependence on x, T_C(x) ~ x^m, where m = 2.2 +/- 0.2 are quantitatively described by a tight binding model of superexchange interactions and Monte Carlo simulations of T_C. The critical behavior of this dilute magnetic insulator shows strong deviations from the magnetically clean case (x = 1), in particular, (i) an apparent breakdown of the Harris criterion; (ii) a non-monotonic crossover in the values of the susceptibility critical exponent gamma_eff between the high temperature and critical regimes, and (iii) a smearing of the critical region, which can be explained either by the Griffiths effects or by macroscopic inhomogeneities in the spin distribution with a variance Delta x = (0.2 +/- 0.1)%. Comment: 5 pages, 5 figures |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1103/PhysRevB.88.081201 |
| URL الوصول: | http://arxiv.org/abs/1306.5141 |
| رقم الأكسشن: | edsarx.1306.5141 |
| قاعدة البيانات: | arXiv |
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