SPIN-POLARIZED SURFACE-STATES OF FE(100)

Spin- and angle-resolved photoemission has been used to reinvestigate the origin of some prominent surface-related features of the Fe(100) s pectra. In agreement with earlier studies the spin-integrated spectra show intense surface emission near the Fermi level from states at the center of the surface Brillouin zone. The spin-polarization measuremen ts show that this surface emission is of majority-spin character, in c ontrast with the previous interpretations. By exposing the clean surfa ce to 0.1-0.4 langmuir O2 the intensity of the majority-spin surface-r elated feature is strongly reduced, whereas an oxygen-induced minority -spin state develops with increasing exposures at a binding energy of 1.4 eV.