GIANT MAGNETORESISTANCE IN FE0.95CR0.05/CR MULTILAYER FILMS

We have studied the effect of Cr alloying addition to the Fe layers on the magnetoresistance behavior of the Fe/Cr superlattice films [Fe(15 angstrom)/Cr(8-20 angstrom)]30. The alloyed superlattice films Fe0.95Cr0.05/Cr exhibited significantly improved giant magnetoresistance effect (DELTAR/R approximately 12.2 % at 4.2 K), as compared to the unalloyed Fe/Cr multilayer films (DELTAR/R approximately 6.9%). The M-H loops indicate that antiferromagnetic coupling exists in both films, which is believed to be responsible for the observed giant magnetoresistance. The improvement in DELTAR/R in the Cr-alloyed superlattice films is attributed to the stronger spin-dependent scattering of conduction electrons caused by the introduction of Cr impurities in the ferromagnetic layers. The alloyed superlattice films also exhibit reduced coercivity and saturation magnetization.