Layered Magnetic Structures: Evidence for Antiferromagnetic Coupling of Fe Layers across Cr Interlayers

We investigated exchange coupling of Fe layers across Au and Cr interlayers by means of light scattering from spin waves. For Au interlayers we find a continuous decrease of this coupling to zero as the Au thickness is increased from 0 to \ensuremath{\cong}20 \AA{}. For Cr interlayers of proper thickness we find antiferromagnetic coupling of the Fe layers. In small external fields such double layers order antiparallel with their magnetization perpendicular to the external field, in analogy to the spin-flop phase of antiferromagnets.