Spin Density in Real and Momentum Space in Multi-Atom Alloys by KKR-CPA Method

The application of the spin-polarized version of multiple scattering theory for obtaining electron charge and spin densities in both real and momentum spaces of concentrated, multi-atom disordered alloys is presented. This method is based on the Korringa-Kohn-Rostoker (KKR) band structure approach and coherent potential approximation (CPA) method. The effective one-electron potential is constructed within local spin density approximation. The magnetic neutron form factors are in real space of our main interest. With the recent developments of new synchrotron photon sources, the Compton profile becomes the most interesting target in momentum space. In the most of examples, spin momentum density and its specific structure due to Fermi surface will be shown. To get accurate enough description in momentum space and quantity like Compton profile, the determination of the Fermi surface must be done with high precision. In this context we show how to apply generalized Lloyd formula for accurate determination of the Fermi level. Also we show how to use efficiently complex energy integration method for the computation of matrix elements, G(r,r) or G(p,p), of the KKR-CPA Green function. Results for the iron-silicon ferromagnetic binary alloys and half-metallic ferromagnetic Heusler alloys are presented.