Influence of crystal structure on the magnetoresistance of Co/Cu multilayers

The saturation magnetoresistance (MR) and Co nuclear magnetic resonance (NMR) spin echo have been measured in a series of sputtered Co/Cu multilayers, with Co thicknesses ranging from 10 to 30 Å. The multilayers were grown on 50 Å Cu or Fe buffer layers. A clear correlation has been established between the MR and the Co NMR line profile. The sample with the highest MR exhibits a single fcc Co line with weak-intensity wings. Increasing the number of (111) layer stacking faults and grain boundaries leads to decreasing MR.