Anderson localization due to spin disorder: a driving force of temperature-dependent metal-semiconductor transition in colossal-magnetoresistance materials

摘要

We study temperature induced metal-insulator transition in dopedferromagnetic semiconductors, described by s-d exchange model. The transitionis a result of the mobility edge movement, the disorder being due to magneticions spin density fluctuations. The electrons are described in the tightbinding approximation. Using ideas and methods of Anderson localization theorywe obtain simple formulas, which connect the mobility edge with short-rangeorder characteristics of the magnetic subsystem -- static spin correlators. Wediscuss the application of the theory to several groups of novelcolossal-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.