SINGLE-SITE FUNCTIONAL-INTEGRAL APPROACH TO ITINERANT-ELECTRON FERROMAGNETISM .2. THERMODYNAMICAL PROPERTY

Thermodynamical properties of ferromagnetic metals are discussed by using the single-site functional-integral method developed recently by the present author. It is shown that the entropy and the specific heat consist of two terms; one is due to the thermal excitations of electrons near the Fermi level, and the other arises from the disordered local magnetic moment. Numerical calculations show a huge specific-heat-peak due to magnetic contributions at the Curie temperature, Tc, and a large electronic specific heat at low temperatures and at T>Tc, which are qualitatively in agreement with experimental data of ferromagnetic metals like iron. © 1979.