Arrays of multilayered nanowires

Multilayered Co/Cu wires with a diameter of 80 nm and a length of 6 mu m were produced by electrodeposition in nanoporous polycarbonate membranes. Their magnetoresistance has been measured in a geometry where the current was perpendicular to the layer plane. The anisotropic part of the magnetoresistance was limited to 1.5%. The study, for layer thicknesses ranging from 3 to 100 nm interpreted in terms of the Valet and Fert model gave estimates of the spin dependent bulk and interface resistivities acid their change with temperature. The large Co bulk resistivity value, caused by a large amount of Cu impurities, limited the magnetoresistance in our samples to 20% at room temperature and 30% at 20 K. The Cu spin flip mean free path was found to be temperature independent and determined by scattering at Co impurities in the Cu layer. It was measured for two sets of samples with different amounts of Co impurities. (C) 1996 American Institute of Physics.