GIAN MAGNETORESISTANCE IN MELT-SPUN METALLIC RIBBONS

We report the observation of giant magnetoresistance in as-quenched and annealed metallic ribbons prepared by melt-spinning in an argon atmosphere. The samples consist of heterogeneous CoxCu1-x alloys with x varying between 5 and 30%. A magnetoresistance of the order of 20% in 50 kOe at 5 K is obtained in these samples after optimized annealing. The amplitude of this magnetoresistance is similar to that obtained in sputtered samples of the same composition. In contrast to techniques of thin-film growth (sputtering, UHV evaporation, MBE), this method of preparation allows for the production of a large quantity of material exhibiting giant magnetoresistance in the form of ribbons or wires which are a few tens of microns thick, a few millimeters wide and tens of meters long.