LANGEVIN-LIKE GIANT MAGNETORESISTANCE IN CO-CU SUPERLATTICES

We present evidence for a new type of giant magnetoresistance in (111) cobalt-copper superlattices with atomically smooth interfaces. We pro pose that the lowered dimensionality of the structure leads to an enha ncement of the scattering of conduction electrons from paramagnetic in terfaces obeying a Langevin-like saturation at very high fields, well beyond the switching field of the Co layers. The findings help to expl ain similarities in magnetotransport behavior with recently reported g ranular systems as well as differences with antiferromagnetically coup led multilayers.