Electronic energy bands of lead: Angle-resolved photoemission and band-structure calculations

Abstract

Angle-resolved photoemission with synchrotron radiation was applied to Pb(111) in order to determine the electronic band structure of Pb. The L direction was mapped out by recording normal-emission photoelectron spectra. Band energies at several symmetry points in the Brillouin zone were obtained by evaluation of off-normal spectra. An adjusted free-electron parabola describes the empty bands well when compared with the critical points resulting from our band-structure calculation using the self-consistent linear rigorous cellular method. The occupied bands close to the Fermi energy agree well with theory, particularly with respect to the magnitude of the spin-orbit splitting, whereas there are discrepancies for the lowest occupied valence band. Inelastic scattering of photoelectrons gives rise to additional peaks in the spectra which cannot be attributed to direct transitions. No surface state was observed in the s-p band gap. © 1984 The American Physical Society.