Anomalous Pressure Dependence Of The Giant Magnetoresistance For Co/Cu Magnetic Multilayers

The effect of pressure of up to 2.2 GPa on the giant magnetoresistance (GMR) has been investigated for sputtered [Co(10.8 A)/Cu( t Cu A)] 15 magnetic multilayers with various Cu-layer thicknesses, t Cu . It was found that the MR ratio, Δρ/ρ s , showing oscillatory behavior with t Cu , is strongly affected by the application of pressure at 4.2 K for the samples near the first peak ( t Cu =9.8 and 11.7 A): Δρ/ρ s for t Cu =9.8 decreases with increasing pressure, while Δρ/ρ s for t Cu =11.7 increases with increasing pressure. On the other hand, the pressure effect on Δρ/ρ s for the samples near the second peak ( t Cu =21.5 and 23.4 A) is much smaller than that near the first peak.