Ruderman-Kittel-Kasuya-Yosida Spin Polarization in a Strongly Perturbed Medium and Applications to Hyperfine Fields

Abstract

Hyperfine fields at normal impurities in ferromagnetic metals and alloys vary systematically in sign and magnitude. These results are explained by an extension of Ruderman-Kittel-Kasuya-Yosida spin polarization to the case of an electron gas with a strong local perturbation.