Electronic structure calculations in ordered and disordered solids with spiral magnetic order

A scheme to calculate the electronic structure of systems having a spiral magnetic structure is presented. The approach is based on the Korringa-Kohn-Rostoker Green's function formalism which allows, in combination with the coherent potential approximation alloy theory, dealing with chemically disordered materials. It is applied to the magnetic random alloys FexNi1-x, FexCo1-x, and FexMn1-x. For these systems the stability of their magnetic structure was analyzed. For FexNi1-x the spin stiffness for was determined as a function of concentration that was found in satisfying agreement with experiment. Performing spin spiral calculations the longitudinal momentum-dependent magnetic susceptibility was calculated for pure elemental systems (Cr, Ni) in the nonmagnetic state as well as for random alloys (AgxPt1-x). The obtained susceptibility was used to analyze the stability of the paramagnetic state of these systems.