Enhanced temperature-dependent magnetoresistivity of Fe/Cr superlattices

The temperature dependence of the magnetoresistivity is found to be much larger in Fe/Cr superlattices with rough interfaces (high magnetoresistance) than those with sharp ones (small magnetoresistance). We discuss the mechanisms which produce this temperature dependence and point out that symmetry conditions restrict the putative mechanisms in superlattices. We show that the enhanced temperature dependence of the magnetoresistance can be explained by the existence of local spin excitations at the roughened Fe/Cr interfaces.