Scanning tunneling spectroscopy study of the edge surface states on oxygen-etched graphite surface with the presence of liquid crystal steps

Scanning tunnelling microscopy and spectroscopy are used to study electronic states at the edges of the monolayer graphite pits and liquid crystal steps. The graphite edge surface state exhibits a maximum in the local density of states in the energy range of 0.02 - 0.15 eV above the Fermi level. The edge state on the liquid crystal steps is not seen by tunnelling spectroscopy measurements. It is caused by the lack of the carbon zigzag regions leading to specific topology of the pi electron networks. (C) 2001 Elsevier Science Ltd. All rights reserved.