Evidence for the spin polarization of copper in Co /Cu and Fe /Cu multilayers

Magnetic circular x-ray dichroism on Co /Cu and Fe /Cu multilayers at the K edge of copper shows (i) that the p band of copper is significantly spin polarized by the adjacent Co or Fe atoms, (ii) that the spin polarization of the copper layers strongly depends on the adjacent magnetic layer, and (iii) that the magnetic polarization is not restricted to the interface layer, i.e., it departs from a simple 1/tCu dependence.