Comparative study of the magnetoresistance of electrodeposited Co/Cu multilayered nanowires made by single and dual bath techniques

Muitilayered Co/Cu wires were produced by electrodeposition in nanoporous membranes, with layer thickness in the range of 3 to 100 nm. These samples exhibit a giant magnetoresistive effect with current perpendicular to the plane of the layers (CPP-MR), which can be interpreted in the framework of Valet and Fert's expressions of the two currents model. The results are in accordance with those found for sputtered samples, except the large Co resistivity values shown by our samples, limiting our CPP-MR to 30%. In order to avoid codeposition of Cu in the Co layers, an alternative technique, involving two separate Co and Cu baths, has been used. Layered Co/Cu wires with thickness down IO nm were produced. The study of the temperature variation of the resistivities revealed that the interface resistance severely decreases in the samples produced by the double bath technique compared to the single bath, limiting the magnetoresistance to 10%.