Investigation of epitaxial arrangement and electronic structure of a La@ C-82 film grown on an MoS2 surface

Molecular arrangement and electronic structure of a La@C-82 film epitaxiall y grown on an MoS2 surface have been studied using reflection high-energy e lectron diffraction and electron energy-loss spectroscopy (EELS). It was re vealed that La@C-82 molecules form a close-packed hexagonal lattice on a cl eaved face of MoS2 with the intermolecular distance of 1.13+/-0.03 nm. EELS of the La@C-82 film in the valence excitation region indicated seven peaks coming from pi-->pi* transitions together with the pi-plasmon excitation. The absence of a distinct band gap means that the La@C-82 epitaxial him is not semiconducting, but metallic or semimetallic. From the EELS result, we propose an electronic structure diagram of the La@C-82 epitaxial film.