Surface energy bands of p(1×1)Cr(100) and p(1×1)O/Cr(100)

Angle resolved photoemission spectra have been measured on clean p(1 × 1)/Cr(1 0 0) and p(1 × 1)O/Cr(1 0 0) using a He discharge lamp as an excitation source. The dispersion curves of surface energy bands have been obtained. The results are compared with reported results of the energy band calculation. The measured energy band dispersion curves for the surface states of a clean sample agree well with the calculated bands for the surface state with aligned spins. Some parts of the dispersion curves of the surface bands agree with those of the bulk band. The energy bands observed here appear to be favourable to the surface ferromagnetic state. In case of the sample with adsorbed oxygen, the band dispersion obtained here for the deep band region coincides with the reported data. The bands with binding energies larger than 5 eV are attributed to the O 2p state forming the surface band. The bands within a binding energy of 4 eV from the Fermi level, are ascribed to the bands caused by Cr atoms in the first sub-layer forming the O Cr bond.