OSCILLATORY EXCHANGE COUPLING IN CO CU(111) SUPERLATTICES

By probing the magnetization profile of high-quality molecular-beam-ep itaxy-grown Co/Cu(111) superlattices with spin-polarized neutron refle ctivity (SPNR), we have observed a coherent antiferromagnetic spin str ucture and confirm that this coupling behavior sensitively depends on the Cu spacer thicknesses. We present magneto-optical Kerr-effect data from which the oscillation period of the exchange coupling can be det ermined to be about 9 angstrom, consistent with theory and the SPNR da ta. With these results we confirm the existence of an oscillatory exch ange coupling in this controversial system.