Study of giant magnetoresistance behavior in sputter-deposited CrFe alloy films

Abstract

We report the giant magnetoresistance (MR) behavior in CrFe alloy films and its variation with composition and substrate temperature in conjunction with microstructure observations. The MR observed as a function of Fe concentration shows a maximum around 20 at% Fe at any substrate temperatures. A large difference in the magnitude of MR is observed between the specimens deposited on cooled and heated substrates when the Fe concentrations are lower than 25 at%, while MR values do not depend on the substrate temperature for specimens containing Fe larger than 25 at%. The temperature dependence of the magnetization shows that the magnetization with a zero field cooling exhibits a maximum at a certain temperature ( T p). T p increases gradually as a function of Fe concentration of the specimens, but it starts to increase drastically when the concentration of Fe exceeds 20 at%, where MR shows the maximum value.