Giant magnetoresistance in magnetically inhomogeneous thin films

Abstract

Giant magnetoresistance (GMR) has been observed in thin films of Fe and Co in Ag. The best results were obtained in the Ag-rich samples with a maximum value of 25% in Co20Ag80 at 30 K. The GMR values are slightly increased upon annealing. Magnetic data show a magnetic transition below room temperature which may be due to spin-glass type of behavior. These results are consistent with the microstructure studies which showed a single face centered cubic phase, with very fine grains. Upon annealing separation of the two components is achieved with substantial grain growth.