Ion beam sputtering of magnetoresistive multilayers: Co/Cu and Co-modified Ni/sub 81/Fe/sub 19//Cu systems

The ion beam sputtering method was applied to the preparation of Co/Cu and related multilayers. Improvements were obtained by changing the sputtering gas from Ar to Xe and by increasing the growth rate. By these means we achieved a magnetoresistance effect of 51% at room temperature in Co/Cu multilayers of only 16 periods. With these optimized working conditions Ni/sub 81/Fe/sub 19//Cu multilayers with cobalt interfaces of various thicknesses were prepared. A linear correlation between the magnetoresistance ratio and the antiferromagnetically coupled volume fraction is found indicating a predominant interface contribution to the magnetoresistance effect. On the other hand, cobalt was found to degrade the coupling quality and to enhance the coercivity.