Giant magnetoresistance in periodic and aperiodic electrodeposited Cu-Co multilayers

Nanometric multilayers made of alternating different metals, are widely investigated because of their outstanding properties (mechanical, optical, magnetic...). Electrodeposition is a cheap and relatively easy method for preparing such nanomaterials. Using a pulse-potential electrodeposition method with a single electrolyte, we have prepared Cu/Co multilayers. Five to thirty bilayers with individual thicknesses ranging between 0.5 and 30 Nn, were obtained. Their crystalline state was checked by grazing incidence X-ray diffraction. Their ferromagnetic response upon magnetization shows either the presence of continuity in the layers or of multidomains isolated grains. The large coercive field (few hundred of Oersteds) results from small grain size and internal stresses in the layers. The films show a giant magnetoresistance effect.