Magnetoresistance and galvanomagnetics in bias sputtered Co/Cu multilayers

Co/Cu multilayers have been prepared on glass substrates by sputtering with negative substrate bias voltage. In zero biased films, the magnetoresistance (MR) increases monotonically with the Cu layer thickness (d/sub Cu/) up to 40 AA, resulting from decoupling between the ferromagnetic layers. On the other hand, for -30-V biased films, three oscillation peaks with a period of about 12 AA appear in the d/sub Cu/ dependence of the MR ratio because of the RKKY-like interlayer coupling. In the oscillation peak at d/sub Cu/=24 AA, a sharp MR change occurs at low applied magnetic field, owing to a very small coupling constant of J=0.008 erg/cm/sup 2/. The Hall resistivity and the planar Hall effect have been also measured.<
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