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) spectra. 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 measurements show that this surface emission is of majority-spin character, in contrast with the previous interpretations. By exposing the clean surface to 0.1--0.4 langmuir O₂ the intensity of the majority-spin surface-related feature is strongly reduced, whereas an oxygen-induced minority-spin state develops with increasing exposures at a binding energy of 1.4 eV.