GIAN MAGNETORESISTANCE IN MELT-SPUN METALLIC RIBBONS

We report the observation of giant magnetoresistance in as-quenched an d annealed metallic ribbons prepared by melt-spinning in an argon atmo sphere. The samples consist of heterogeneous CoxCu1-x alloys with x va rying 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. Th e amplitude of this magnetoresistance is similar to that obtained in s puttered samples of the same composition. In contrast to techniques of thin-film growth (sputtering, UHV evaporation, MBE), this method of p reparation allows for the production of a large quantity of material e xhibiting giant magnetoresistance in the form of ribbons or wires whic h are a few tens of microns thick, a few millimeters wide and tens of meters long.