Evidence for an Alkalilike Conduction Band in Alkali Graphite Intercalation Compounds

Abstract

The valence bands of pure graphite and several alkali graphite intercalation compounds were studied by ultraviolet photoelectron spectroscopy ($h\ensuremath{\nu}=21.2$ eV). The most significant observation is an intensity peak at the Fermi energy ${E}_{\mathrm{F}}$ in the intercalation compounds. This peak is mainly due to alkalilike $s$ states. The density of states at ${E}_{\mathrm{F}}$ is enhanced by a factor of 30 compared with pure graphite. The alkalilike conduction bands in the first stage alkali graphite interclation compounds are similar to those of pure alkali metals.