Interlayer coupling across noble metal spacers

We have investigated the exchange coupling of Fe layers across interlayers of Au, Ag, Cu and Au-Cu alloys. In order to evaluate the dependence of the coupling on the interlayer thickness the functional form expected from RKKY-like theory is used. In this way two oscillation periods are evaluated which can be compared with predictions based on the known Fermi surfaces of the interlayer materials. The data from the alloy interlayers suggest that the coupling strength depends strongly on the structural order of the interlayer material. Also in the case of the alloys the changes in the Fermi surfaces with composition are evaluated.