ENHANCEMENT OF ORBITAL MAGNETISM AT SURFACES - CO ON CU(100)

By combining magnetic circular x-ray dichroism experiments with first principles electronic structure calculations, we demonstrate that the orbital contribution to magnetism can be strongly enhanced at surfaces . This effect is illustrated for Co grown on a Cu(100) surface, where the first layer of Co shows an enhancement of the orbital moment (0.26 mu(B)) by a factor of 2 as compared to the bulk. The lowering of the symmetry at the surface, the enhanced spin moment, and the increased v alue of the density of states at the Fermi level are factors that gene rally give the observed enhancements.