Preparation, structure, magnetic, and magnetotransport properties of electrodeposited Co(Ru)/Ru multilayers

It is demonstrated that Co(Ru)/Ru multilayers with a hexagonal close-packed structure can be produced by electrodeposition. For appropriate layer thicknesses, clear giant magnetoresistance (GMR) behavior has been found. The observed GMR is very small (less than 0.1% for 8 kOe at room temperature) but not smaller than the GMR of Co/Ru multilayers prepared previously by high-vacuum methods. It is argued that neither structural imperfection of the multilayers nor chemical intermixing at the interfaces can be the main reason for the small GMR observed in the Co-Ru system for any preparation technique. It is suggested that the strongly reduced spin-dependent scattering characteristics of the interfacial Co-Ru alloys, which was described in a previous paper, might explain the low GMR of Co/Ru multilayers.