GMR OF CO CU MULTILAYERS WITH REDUCED HYSTERESIS AND LOW-FIELD RESPONSE/

We present the results of a systematic study on optimization of the gi ant magnetoresistance (GMR) response in Co/Cu multilayers (MLs) for Cu layer thickness near the second oscillatory peak. Co/Cu MLs with alte rnating thick (t(Co)((1))) and thin (t(Co)((2))) Co layers have been p repared in the form of [Cot(Co)((1))Angstrom/Cu20 Angstrom/Cot(Co)((2) )Angstrom/Cu20 Angstrom](15). We have found that the magnetoresistive hysteresis of these MLs is reduced with decreasing t(Co)((2)) and has disappeared when t(Co)((2)) < 4.5 Angstrom. We have obtained an optima l GMR response with a field sensitivity of 0.13%/Oe over a field regio n of similar to 60 Oe centered at similar to 50 Oe. This architecture may enable the use of Cu/Co MLs in low-field magnetic sensor applicati ons.