Giant magnetoresistance of hysteresis-free Cu/Co-based multilayers

It has been demonstrated that hysteresis-free multilayers based on {Cu/Co} and {Cu/Ni57Co43} can be experimentally realized obtaining room temperature GMR effect amplitudes from 6.5% up to 20%. A critical window for the layer thickness for hysteresis-free GMR curves can be achieved for both systems, ranging from 0.38 to 0.45 nm and 0.59 to 0.7 nm, respectively. The corresp onding sensitivities range from 0.075 up to 0.114%/Oe, but are still below that of normal {Cu/Co} multilayers. Hysteresis-free multilayers based on th ese systems are stable up to 180 degreesC upon isochronal annealing. It is shown that hysteresis-free. {Cu/Co or Ni57Co43}-multilayers are neither a s olution to achieve good temperature stability nor a higher sensitivity comp ared with normal ones and hence are not candidates for application. (C) 200 1 Elsevier Science B.V. All rights reserved.