Spin–density correlations and magnetic neutron scattering in ferromagnetic metals

Abstract

We obtain expressions for the spatial spin-density correlator and for effective and local magnetic moments in the dynamic spin-fluctuation theory. We derive formulas for the magnetic scattering cross section in the theory of itinerant electron magnets. We calculate magnetic characteristics of bcc Fe in the paramagnetic state and compare our numerical results with the polarized neutron scattering experiment. We show that the short-range order in bcc Fe persists up to a temperature much higher than the Curie temperature but at rather small distances (up to 5A).