The technique of template synthesis by electrodeposition in the parallel pores of membranes is enhanced with the alternated deposition of different metals. Filled polycarbonate or alumite membranes constitute regular arrays of embedded wires with diameters ranging from 30nm to a few μm. The composition along the wire can be varied over distances as small as a few nm. The metallic disks thus formed have the diameter of the pores and a thickness controlled by the deposition time. The separation between grains can be controlled by the spacer deposition time and the porosity of the membrane. Applications of these new composite structures are illustrated with magnetic properties and the giant magnetoresistance effect.