Spin and orbital magnetic moments of $3d$ and $4d$ impurities in and on the (001) surface of bcc Fe

Results of ab initio calculations of the magnetic moments of $3d$ and $4d$ transition metal impurities in and on the (001) surface of bcc Fe are presented. These investigations were performed using the spin-polarized relativistic version of the Korringa-Kohn-Rostoker Green’s-function method giving access to the spin as well as the orbital magnetic moments induced by spin-orbit coupling. For the spin magnetic moment only small changes are found compared to a previous scalar-relativistic calculation for the investigated surface impurity systems. In most cases the orbital magnetic moment turned out to be somewhat enlarged compared to that of the impurity dissolved in bulk Fe. A rather simple explanation for the variation of these spin-orbit-induced moments with atomic number of the impurity atom could be given on the basis of perturbation theory.