THE EFFECT OF AGING ON GMR AND MICROSTRUCTURE OF CO10CU90 RIBBONS

The microstructures associated with the spinodal decomposition produce d by isothermal aging for Co10Cu90 ribbons are closely correlated with the giant magnetoresistance (GMR) effect. The MR ratio increases in t he constant wavelength regime where the interface area increases. The decomposition occurs by longer aging, accompanying a substantial growt h of particles. The MR ratio decreases with the increase in the wavele ngth though the field dependence of the MR ratio becomes larger in low fields. The lower isothermal aging temperature, the shorter periodic fluctuation of the composition, and accordingly the largest MR ratio o f 8.1% is achieved by aging at 673 K for 166 h.