CPA density of states and conductivity in a double-exchange system containing impurities
Abstract
We study density of states and conductivity of the doped double-exchange system, treating interaction of charge carriers both with the localized spins and with the impurities in the coherent potential approximation. It is shown that under appropriate conditions there is a gap between the conduction band and the impurity band in paramagnetic phase, while the density of states is gapless in ferromagnetic phase. This can explain metal-insulator transition frequently observed in manganites and magnetic semiconductors. Activated conductivity in the insulator phase is numerically calculated.
- Publication:
-
European Physical Journal B
- Pub Date:
- 2001
- DOI:
- 10.1007/s100510170298
- arXiv:
- arXiv:cond-mat/0006184
- Bibcode:
- 2001EPJB...19..525A
- Keywords:
-
- 75.50.Pp;
- 75.30.Vn;
- 72.10.-d;
- Magnetic semiconductors;
- Theory of electronic transport;
- scattering mechanisms;
- Condensed Matter
- E-Print:
- 5 pages, 2 eps figures, LaTex2e, EPJ macro package (style files included). The calculations done for realistic model predict that a gap appears between the conduction band and the impurity band in paramagnetic phase, while the density of states is gapless in ferromagnetic phase