Current-perpendicular-to-the-plane giant magnetoresistance of an all-metal spin valve structure with Co_(40)Fe_(40)B_(20) magnetic layer

摘要

A current-perpehdicular-to-the-plane giant magnetoresistance is demonstrated at room temperature by using Co_(40)Fe_(40)B_(20) alloy with an exchange biased stack of IrMn/CoFeB/Cu/CoFeB. The GMR effect is significantly enhanced by inserting a Co_(75)Fe_(25) layer between CoFeB and Cu spacer to adjust the interfacial resistance and improve the interfacial asymmetric spin scattering at the interfaces with spacer. Microstructure observation shows that boron of the top CoFeB layer prefers to be enriched at the interface with Ru capping layer after annealing.