Analysis of phonons in graphene sheets by means of HREELS measurement and ab initio calculation

We have grown epitaxial thin sheets of graphene on BC3/NbB2(0001) and measured phonon dispersion curves of the graphene sheets by means of high-resolution electron energy-loss spectroscopy (HREELS). The phonon dispersion curves have been calculated on the basis of ab initio calculations. The observed curves were in good agreement with theoretical curves. The quality of crystallinity of the grapheme layers was high compared-with the bulk graphite crystals. In this paper, we demonstrate that the combination of HREELS measurement and ab initio calculations is extremely effective for investigation of honeycomb-structured materials. Copyright (C) 2005 John Wiley Sons, Ltd.