CPP giant magnetoresistance of NiFeCo/Cu/CoFe/Cu multilayers

CPP (Current perpendicular-to-plane) magnetotransport measurements have been performed on lithographically patterned magnetic multilayers of NiFeCo/Cu/CoFe/Cu. We implement chemical-mechanical polishing to produce very low Cu-Cu interface resistance that allows accurate, intrinsic giant magnetoresistance (GMR) values to be obtained. Measured GMR is found to be dependent on device size but can be interpreted as the change in the resistivity of the magnetic multilayer and the effects of non-uniform current distribution. Computer simulations account for the non-uniform current distribution and allow us to determine the intrinsic CPP GMR and verify the negligible contact resistance in these structures.