EFFECT OF RESIDUAL WATER ON GIANT MAGNETORESISTANCE IN CO CU SUPERLATTICES/

We have studied the effects of residual water during the deposition pr ocess and the deposition rate on the giant magnetoresistance (GMR) in Co/Cu superlattices prepared by sputtering. The magnetoresistance (MR) ratio decreases drastically with an increase in the amount of residua l water and a decrease in the deposition rate. In order to understand these results, we introduce the residual water to deposition rate rati o parameter, xi, which is proportional to the exposure of the surface of the sample to residual water. It has been found that the MR and mag netic properties of the superlattices are universally expressed in ter ms of xi.