ANDERSON LOCALIZATION IN FERROMAGNETIC SEMICONDUCTORS DUE TO SPIN DISORDER .3. SELF-CONSISTENT LOCALIZATION THEORY AND INELASTIC-SCATTERING

Theoretical investigations are made of the temperature dependence of n‐type EuS electroconductivity. The scattering of electrons by magnetic ion spin‐density fluctuations is found to be strong; selfconsistent localization theory is used to calculate the conductivity and the inelasticity of scattering due to spin dynamics is also taken into account. It is shown that due to inelasticity the states which are localized in the elastic scattering approximation become weekly conducting, and the change of the conductivity of the extended states can be neglected. Hence in the case of quasielastic scattering (though not very rigorously) the notion of the “mobility edge” i. e. the energy which separates large and small conductivity can be introduce. The conductivity in the “dielectric phase” i. e. at temperatures close enough to TC when the “mobility edge” lies above the Fermi level, is estimated. The estimation obtained agrees well with the experimentally observed values. Copyright © 1990 WILEY‐VCH Verlag GmbH & Co. KGaA