Measurements were made of the k-resolved inverse photo-emission spectra of (001) in order to study unoccupied surface states. Surface states were observed near to the Fermi level and at 6.8eV above Fermi level, which originated from La 5d and La 4f states, respectively. The surface state near to the Fermi level exhibited energy dispersion along the Γ-M direction of the surface Brillouin zone, which did not agree with that of a theoretical calculation. It was deduced that, at a (001) surface, electrons were transferred from the sub-surface to the topmost La layer. This charge redistribution could reduce surface dipole moments.

Unoccupied Surface States of LaB6 (001) Studied by k-Resolved Inverse Photoemission. Morimoto, O., Kunii, S., Kakizaki, A.: Physical Review B, 2006, 73[24], 245423