Fully relativistic ab initio treatment of spin-flip scattering caused by impurities

We present a fully relativistic approach for the first-principles calculation of the spin-relaxation time of conduction electrons caused by substitutional impurities. It is an extension of our previous nonrelativistic perturbative approach. The approach is based on a relativistic Korringa-Kohn-Rostoker Green's function and band-structure method. As an application, we obtain the spin-flip scattering time for a Cu host with different types of impurities. It is shown that the perturbative approach fails for impurities lighter than the host atoms, while the relativistic treatment provides good agreement with conduction-electron spin-resonance experiments for all considered impurities.