The effect of Au impurities at the interfaces on the magnetoresistance of MBE-grown Co/Cu multilayers

We have grown Co/Cu multilayers by MBE using a shuttering arrangement wherein half of the sample receives an amount of Au impurities at each interface. Under these controlled conditions, the differences in measurements between each half is attributed only to the effect of the impurities. The samples were characterized by x-ray diffraction and RHEED. We have found that small fractions of a monolayer of Au deposited at the Co/Cu interface significantly decreased the GMR. These results are discussed in the light of current theories on the role of bulk and interface scattering.