Giant magnetoresistance in Co/Cu multilayers with very thin Co layers: Reduced hysteresis at the second antiferromagnetic maximum

We describe the dependence of magnetoresistance and magnetoresistive hysteresis upon the Co layer thickness in Co/Cu multilayers with Cu layer thickness equal to 20 Angstrom, i.e., at the second antiferromagnetic maximum. When the Co layer thickness is reduced to 3 Angstrom the magnetoresistive hysteresis disappears. The elimination of hysteresis is accompanied by a decrease of magnetoresistance, but the sensitivity to changes in the magnetic field is only reduced by a factor of 2. This result makes available the larger sensitivity of the second antiferromagnetic maximum to applications that are adversely affected by hysteresis. (C) 1996 American Institute of Physics.