Properties of electrodeposited Co-Cu multilayer structures

Alternate layers of Co and Cu of individual layer thicknesses from 1.5 to 8.0 nm and total thickness of about 100 layers and of Co bilayers separated by Cu have been electroplated from an electrolyte having a low concentration of Cu and a high concentration of Co atoms. The properties of the resulting structures have been analyzed using SEM, x-ray diffraction, VSM, and FMR methods. Comparable structures have also been fabricated by e-beam evaporation in high vacuum for comparison purposes. X-ray diffraction patterns indicate only the fcc structure. Assuming the Co thickness to be that deduced from the plating charge, we infer 4πM values in the range 6.0–14.5 kG from VSM and FMR. Some uniaxial anisotropy is apparent in this system. These results are similar to those of earlier work on thin fcc Co layers in the same range of thicknesses, where the room-temperature moment was reduced but depended only slightly on layer thickness, and where the uniaxial anisotropy was observed to be small.