Modification of the electronic structure of graphite by intercalation, chlorination and ion etching

Intercalation of graphite with metal chlorides, treatment of graphite with chlorine gas and argon ion etching modify the electronic structure of HOPG graphite. Using both core level and valence band photoelectron spectroscopy significant changes near the Fermi energy were detected. Charge transfer effects in intercalated graphites can be distinguished from irreversible effects arising in all three modifications from the creation of sp3-hybridised carbon atoms. The formation of insulating surface structures is discussed.