Magnetic Properties of Iron and Cobalt in a Combined Model of Itinerant Electrons and Localized Spins

Abstract

AbstractThe temperature variations of the spontaneous magnetization and spin paramagnetic susceptibility are calculated numerically, using molecular field theory, for the combined model of localized spins and itinerant electrons proposed by Edwards for some 3d transition metals. A simple parabolic band is assumed for the itinerant electrons and results are given for those values of the effective mass and exchange parameters which give the best fit to the observed properties of iron and cobalt. A reasonable description of the magnetic properties of b.c.c. iron is obtained and the calculated curves have none of the instability against small changes in values of parameters which is characteristic of pure Stoner theory applied to iron and cobalt. Agreement with the observed temperature dependence of the susceptibility of cobalt could not be obtained and a more sophisticated theory may be required.