2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/27399It is shown how the exchange coupling between two ferromagnetic planes embedded in an infinite non-magnetic metal, regarded as a function of the distance between the planes, may contain important components which oscillate with periods not predicted by RKKY theory. The interesting case of a FCC(110) structure with a Cu-like Fermi surface is discussed in detail.14 pages, REVTEX, including 4 figuresCondensed Mattertext