The effect of aging on GMR and microstructure of Co10Cu90 ribbons

The microstructures associated with the spinodal decomposition produced by isothermal aging for Co10Cu90 ribbons are closely correlated with the giant magnetoresistance (GMR) effect. The MR ratio increases in the constant wavelength regime where the interface area increases. The decomposition occurs by longer aging, accompanying a substantial growth of particles. The MR ratio decreases with the increase in the wavelength 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 of 8.1% is achieved by aging at 673 K for 166 h.