INFLUENCE OF INTERDIFFUSION ON THE INTERFACIAL MAGNETISM IN FE RU SUPERLATTICES/

We study the effect of interdiffusion on the magnetism of two Fe/Ru su perlattices representative of the two structures proposed in the liter ature. Our approach is a combination of the layer Korringa-Kohn-Rostok er method with the multiple-scattering spin-polarized version of the c oherent-potential approximation. We find that even a 20% alloying in t he boundary planes produces only an insignificant reduction of the Fe moments at the interface, so that interdiffusion cannot be at the orig in of the magnetically dead layers observed in these systems. From an analysis of results for bulk alloys we deduce that local geometrical r elaxation and possibly on-site Coulomb interactions of the Fe 3d elect rons are responsible for the moment suppression.