Clear correspondence between magnetoresistance and magnetization of epitaxially grown ordered FeRh thin films

Magnetoresistance and magnetization of the CsCl-type ordered FeRh epitaxial thin films grown on MgO(001) substrates are investigated as a function of temperature and film thickness. All the films show a clear first-order magnetic phase transition from the antiferromagnetic state to the ferromagnetic state at around 380 K. A large negative variation in the field-dependent magnetoresistance of the FeRh thin films, which is accompanied by the field-induced magnetic phase transition, is found to be well scaled with the magnetization squared M². The results indicate that the magnetoresistance primarily arises from spin-dependent scattering through the s-d exchange interactions between conduction electrons and the localized magnetic moments.