Unoccupied spin-split surface state on Co(0001): experiment and theory

We report on spin-resolved inverse photoemission data from Co(0001). In par ticular, we identified an unoccupied crystal-induced surface state located at <(<Gamma>)over bar> in the surface Brillouin zone. The surface state exh ibits an exchange splitting of 0.66 +/- 0.03 eV with both majority and mino rity parts located in energy above the Fermi level. The experimental data a re compared with bandstructure and spin-polarized inverse-photoemission cal culations, which we obtained in the framework of a fully relativistic one-s tep theory developed for ferromagnetic materials. Both experiment and theor y agree in locating the minority as well as the majority components of the surface state above the Fermi level. (C) 2001 Elsevier Science B.V. All rig hts reserved.