Magnetic layer thickness dependence of the interlayer exchange coupling in (001) Co/Cu/Co

Abstract

A dependence of the strength of the antiferromagnetic coupling across Cu on the Co layer thickness has been observed in an epitaxial fcc (001) triple wedge sample containing two Co wedges and one Cu wedge. Our result is consistent with an oscillation period of 6--7 \AA{} Co---a value that agrees with the period of 3.5 monolayers of Co derived from the extremal wave vector that spans the ellipsoidal hole pocket centered at the X point of the fcc Co spin-down Fermi surface. This shows that the interlayer exchange coupling does not just involve an interaction localized at the interfaces, but is a property of the sandwich as a whole.