Angle-resolved resonant photoemission of Ni(100) and Ni(110) single crystals

We have studied the valence band photoemission spectra of Ni(100) and Ni(110) single crystals near the excitation threshold for 3p core electrons. The resonant behavior of the 6 eV satellite does not depend on both the surface orientation and the polarization of the electric vector of an incident light for excitation. These results indicate that the 6 eV satellite should be under little influence of spatial symmetry of the valence band. In the angle-resolved photoemission spectra of Ni(100), we have observed another broad feature near the 6 eV satellite. It shows the large energy dispersion and is interpreted as due to the interband transition. In Ni(110), we have observed the weak valence band satellites at binding energies of about 9.3 eV and 13.4 eV. They do not show well-defined resonance around the 3p threshold.