Enhanced orbital magnetism at the nanostructured Co/Cu(1 1 13) surface

Epitaxial growth of cobalt on a stepped copper surface leads to thin films displaying unusual electronic and magnetic properties. Strong changes in 3d electron localization near the surface of the Co film augment the ground-state energy compared to the bulk of the film. The Co orbital magnetic moment per spin is separated into bulk and surface contributions using magnetic circular x-ray dichroism. Symmetry breaking due to finite size effects results in an increase (200%) of the orbital moment near the surface.