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

Abstract

Giant magnetoresistance (GMR), magnetization and structure of granular Cu 90Co 10 alloy were investigated. The annealed sample is inhomogeneous with respect to the Co-particle sizes and interparticles distances and, therefore, not all particles behave superparamagnetically. The observed deviation from the expected theoretically quadratic dependence of GMR on magnetization can be attributed to differentiated surface-to-volume ratio of superparamagnetic particles as well as to the presence of a small amount of ferromagnetic phase which is created by relatively large Co-rich regions.