Report
Microscopic model for the semiconductor-to-ferromagnetic-metal transition in FeSi$_{1-x}$Ge$_{x}$ Alloys
| العنوان: | Microscopic model for the semiconductor-to-ferromagnetic-metal transition in FeSi$_{1-x}$Ge$_{x}$ Alloys |
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| المؤلفون: | Yang, Kai-Yu, Yamashita, Y., Läuchli, A. M., Sigrist, M., Rice, T. M. |
| المصدر: | EPL 95 (2011) 47007 |
| سنة النشر: | 2011 |
| المجموعة: | Condensed Matter |
| مصطلحات موضوعية: | Condensed Matter - Strongly Correlated Electrons |
| الوصف: | The simplified bandstructure introduced by Mazurenko et al to model FeSi is used to analyze the singlet semiconductor to ferromagnetic metal transition in the isoelectronic isostructural alloys, FeSi$_{1-x}$Ge$_x$. The complex bandstructure of the alloy is replaced by an alternating chain of doubly and singly degenerate atoms to represent Fe and Si/Ge respectively. The former(latter) form narrow(broad) bands with a substantial hybridization between them. A substantial onsite repulsion including a Hund's rule coupling is introduced on the Fe sites. The mean field phase diagram contains a first order phase transition from the singlet semiconductor to a ferromagnetic metal with increasing temperature and interaction strength similar to the alloys. The analysis also reproduces the rapid rise of the spin susceptibility in the semiconductor with a crossover to a Curie-Weiss form at higher temperatures. Good agreement is found at zero temperature between the mean field and accurate DMRG calculations. Comment: 6 pages, 9 figures |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1209/0295-5075/95/47007 |
| URL الوصول: | http://arxiv.org/abs/1102.1190 |
| رقم الانضمام: | edsarx.1102.1190 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1209/0295-5075/95/47007 |
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