Magnetoresistance of Annealed CoNb/Cu Multilayers with Amorphous CoNb Magnetic Layers

CoNb/Cu multilayers with amorphous CoNb magnetic layers were prepared by rf-sputtering method and then annealed at various temperatures in a high vacuum. A maximum magnetoresistance ratio of 2.83% at room temperature was obtained under a relatively low saturation field of about 200 Oe for the optimum annealing temperature of 400° C. The structural, magnetic and transport properties were strongly influenced by the annealing temperature, and the transport properties were explained on the basis of granular multilayered structures. The magnetoresistance ratio also depends on the thickness of CoNb and Cu layers.