The application of CPA and its extension to ferromagnetic transition-metal alloys

A review is given of certain methods for calculating the electronic and magnetic structure of ferromagnetic transition-metal alloys based on the coherent potential approximation and its extension. Three subjects are discussed in detail. (1) The response of the alloys to an external magnetic field is calculated on the basis of the single-site CPA combined with the Hartree-Fock approximation for fcc Ni-Fe, bcc Fe-Ni and Fe-Co alloys. (2) A method of treatening the effect of the nearest-neighbor composition on the basis of an extension of CPA is discussed. The dependence of the Fe atomic magnetic moment and other quantities on the nearest neighbor composition in bcc Fe-Co and Fe-V alloys is calculated as an example of the applications of this method. (3) A method of carrying out the single-site CPA for the muffin-tin potential model is proposed. Some preliminary results are presented.