Coordination dependence of hyperfine fields of 5sp impurities on Ni surfaces

Abstract

We present first-principles calculations of the magnetic hyperfine fieldsHhf of 5sp impurities on the (001), (111), and (110) surfaces of Ni. We examine the dependence ofHhf on the coordination number by placing the impurity in the surfaces, on top of them at theadatom positions, and in the bulk. We find a strong coordination dependence ofHhf,different and characteristic for each impurity. The behaviour is explained in terms of theon-site s–p hybridization as the symmetry is reduced at the surface. Our results are inagreement with recent experimental findings.