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 (OV) films, the magnetoresistance (MR) increases monotonically with the Cu layer thickness (d(Cu)) up to 40 angstrom resulting from decoupling between the ferromagnetic layers. On the other hand, for -30V biased films, three oscillation peaks with the period of about 12 angstrom appear in the d(Cu) dependence of MR ratio because of the RKKY like interlayer coupling. In the oscillation peak at d(Cu)=24 angstrom, a sharp MR change occurs at low applied magnetic field, owing to a very small coupling constant of J=0.008 erg/cm2. The Hall resistivity and the planar Hall effect have been also measured.