An Application of the Coherent Potential Approximation to Ferromagnetic Alloys

Abstract

An application of the coherent potential approximation (CPA) to ferromagnetic alloys is discussed on the basis of a nondegenerate tight-binding model. The intraatomic coulomb interaction is taken into account self-consistently within the framework of the Hartree-Fock approximation. Numerical calculations are carried out for the case of Ni 1- x Fe x . The results are in good agreement with the experimental data of the magnetic moments of Ni and Fe in concentrated alloys and also with the data of the electronic specific heat. The instability of the nonmagnetic state at a finite temperature is discussed by calculating the susceptibility in CPA. Possible experiments to check the calculated electronic structure are discussed. An extention to a degenerate (multiband) tight-binding model is also presented.