Electron correlation in ferromagnetism. II. hybridization of s and d bands

Abstract

The problem of electron correlation in the ferromagnetism of transition metals is investigated by taking an approximate model Hamiltonian which takes into account the hybridization of the s and d bands. The Green's-function technique is used to obtain the self-consistent ferromagnetic solutions within the Hartree-Fock approximation. An approximate solution of the correlation problem is obtained. The ferromagnetic solutions for which the correlation effects are taken into account are compared with those in the Hartree-Fock approximation. The model is used to investigate the role of the s-d interaction in metal-nonmetal transitions. It is also possible to understand the difficulty of observing pressure-induced nonmetal-metal transition.