High-temperature resistivity of degenerate ferromagnetic semiconductors

The high-temperature portion of the resistivity peak in the degenerate ferr omagnetic semiconductors related to the magnetoimpurity scattering of charg e carriers is investigated. The number of localized carriers in the tempera ture-dependent band tail and their inverse relaxation time are determined i n terms of a generalized magnetoelectric response function relating the bin ary spin correlation functions to an external electric field,Well above the Curie point, both these quantities decrease with increasing temperature. A generalized Mott criterion is found for the temperature, at which the high ly-conductive state loses its stability in the paramagnetic region. (C) 199 9 Published by Elsevier Science B.V. All rights reserved.