Anderson localization due to spin disorder: a driving force of temperature-dependent metal-semiconductor transition in colossal-magnetoresistance materials
Abstract
Description
We study temperature induced metal-insulator transition in doped ferromagnetic semiconductors, described by s-d exchange model. The transition is a result of the mobility edge movement, the disorder being due to magnetic ions spin density fluctuations. The electrons are described in the tight binding approximation. Using ideas and methods of Anderson localization theory we obtain simple formulas, which connect the mobility edge with short-range order characteristics of the magnetic subsystem -- static spin correlators. We discuss the application of the theory to several groups of novel colossal-magnetoresistance materials and include the reproduction of the paper [E. M. Kogan and M. I. Auslender, phys. stat. sol. (b) vol. 147, 613 (1988)] published by us 10 years ago.
6 pages, revtex, epsf, 3 ps figures. A typo in the final result (Eq. (23)) is corrected
6 pages, revtex, epsf, 3 ps figures. A typo in the final result (Eq. (23)) is corrected