Interlayer exchange coupling in Fe/Cr multilayers

Abstract

We investigate the origin of the long period oscillation of the interlayer\nexchange coupling in Fe/Cr trilayer systems. Within the stationary phase\napproximation the periods of the oscillations are associated with extremal\nvectors of the Fermi sphere of Cr. Using a realistic tight-binding model with\nspin-orbit interaction we calculate the coupling strength for each extremal\nvector based on the spin-asymmetry of the reflection amplitude for a\npropagating state impinging from the Cr to Fe layer. We find that for (001) and\n(110) growth direction the biggest coupling strength comes from the extremal\nvector centered at the ellipsoid N of the Fermi surface of Cr.\n