The effect of particle size and surface-to-volume ratio distribution on giant magnetoresistance (GMR) in melt-spun Cu-Co alloys

Giant magnetoresistance (GMR), magnetization and structure of granular Cu90 Co10 alloy were investigated. The annealed sample is inhomogeneous with res pect to the Go-particle sizes and interparticles distances and, therefore, not all particles behave superparamagnetically. The ob served deviation fro m the expected theoretically quadratic dependence of GMR on magnetization c an be attributed to differentiated surface-to-volume ratio of superparamagn etic particles as well as to the presence of a small amount of ferromagneti c phase which is created by relatively large Go-rich regions. (C) 1999 Else vier Science B.V. All rights reserved.