Giant Magnetoresistance and Microstructure of Melt-Spun Cu₇₀Co₃₀ Ribbons

This paper reports an investigation on the giant magnetoresistance and microstructure evolution in melt-spun Cu₇₀Co₃₀alloy. The results show that the phase separation is inevitable in the course of quenching, leading to the formation of two types of fcc magnetic Co-rich particles but these do not appear to contribute to the magnetoresistance (MR). On annealing, a very fine distribution of Co-rich precipitates forms at temperatures above 573 K which are responsible for the high MR developed in this material.