Effects of rare earth addition on giant magneto-resistance performance of Cu-Co-Ni alloys

The effects of microalloying with rare earth elements on giant magnetoresistance (GMR) of melt spun Cu-Co-Ni ribbons were investigated. The results show that light rare earth, such as Ce, La and Nd can improve GMR performance of melt spun Cu80Co15Ni5 ribbons when the mass fractions are between 0.05%-0.07%, especially for Ce. On the contrary, The additions of heavy rare earth Dy and Tb would weaken GMR ratio. However, when the addition mass fractions of light rare earth are more than 0.1%, GMR ratio can be decreased. In GMR the Re addition plays a significant role for purifying melt, promoting precipitates process and increasing the volume fractions of the fine Co-rich precipitates.