Self-excited giant magnetoresistance in Ag/Co and Fe/W multilayers

Giani magnetoresistance (GMR) in multilayered (ML) structures under current loading is reported herein. Agleo and WIFe MLs with 2 or 3 bilayers and an additional bottom Co or Fe layer, respectively, were e-beam deposited The GMR response was measured in dynamic conditions using ac driving current (50 Hz). The same current created the internal magnetic field Hac for the excitation of the GMR. Experimental MLs were characterized using XRR and XRD. The third harmonic of the driving current was dominating frequency component in the MR signal. The GMR ratio was 1.5 %for WIFe MIs and 0.4 % for AglCo MLs with 3 hilayers at the driving current of 70 mAo The formation of 3M harmonic is explained by temporal and spacial redistributions of current in ferromagnetic and spacer layers.