Current-induced magnetization reversal in NiFe/Cu/Co/Au notched mesoscopic bars

In-plane current-induced and field-induced magnetization reversal in notched 2.1 mu m longx270 nm wide pseudo-spin-valve NiFe/Cu/Co/Au thin-film bars has been characterized and compared with the results of a three-dimensional micromagnetic model. The reversal of the soft NiFe layer is influenced by the magnetostatic fields of the hard Co layer, which can initiate switching of the NiFe layer from both ends of the bars, allowing for the existence of field-induced magnetic configurations containing one or two domain walls positioned at different notches. Current-induced reversal of both the NiFe and Co layers occurred for both directions of current flow in the presence of a bias field, and the reversal process differed from that found for field-induced reversal. Micromagnetic simulations including the Oersted field distribution created by the current pulses show that this term alone can account for the current-induced reversal.