Giant Magnetoresistance in NiFeCo/Cu Multilayers.

NiFeCo/Cu multilayers with NiFeCo buffer layers prepared by RF magnetron sputtering show the giant magnetoresistance (MR) effect with oscillations as a function of Cu thickness. At the second peak of the oscillation, the multilayers show an MR ratio of 12% in a field as low as 50 Oe. The structure and the MR properties are stable against annealing up to about 300°C. A field sensitivity of about 0.4%/Oe is obtained for the minor loop of the MR curve measured in a field along the hard axis. The fieid sensitivity is almost constant in the frequency range up to 1 MHz.