| Giant magnetoresistance(GMR) has been investigated for nano-granular Co_xCu_(100-x)(X = 10, 20, 30) sputtered films. Solid solutions were obtained in a wide range of concentration and the microstructure associated with the spinodal decomposition was observed by after-aging. Guinier radii, which were evaluated by small angle neutron scattering, of Co magnetic particles in the Co_xCu_(100-x)(X = 10, 20, 30) films aged at 773K for 1h were 1.3-1.5 ㎚ and the surface-to-volume ratio of Co magnetic particles increased with increasing Co concentration. The MR ratio of Co-Cu films aged at 773K for 1h has the largest value, 7.6%, in 20 at.% Co concentration and decreases in 30 at.% Co concentration. However, the field dependence in low field increased with increasing Co concentration. These behaviours were investigated in terms of the Co particle size, the surface-to-volume ratio and the inter-distance between the Co particles. |
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