Ion Beam Sputtering Of Magnetoresistive Multilayers: Co/Cu And Co-Modified Ni81fe19/Gu 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 Ni81Fe19/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.