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We have grown epitaxial thin sheets of graphene on BC 3 /NbB 2 (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 graphene 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.

The entire phonon-dispersion curves along the Gamma-M direction of a BC3 honeycomb sheet have been determined both experimentally and theoretically for the first time. Most of the observed curves agreed with the theoretical ones calculated on the basis of ab initio theory. From the stretching force constants of the nearest-neighbor C-C and B-C bonds, together with that of the B-B bond, we clarified the characteristic feature of the C-C and B-C bonds. From the experimental and theoretical results, we discussed the possibility of high T(c).

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We report a versatile method based on low vacuum annealing of cellulose acetate on nickel (Ni) surface for rapid fabrication of graphene and carbon nanotube (CNT)-graphene hybrid films with tunable properties. Uniform films mainly composed of tri-layer graphene can be achieved via a surface precipitation of dissociated carbon at 800 °C for 30 seconds under vacuum conditions of ∼0.6 Pa. The surface precipitation process is further found to be efficient for joining the precipitated graphene with pre-coated CNTs on the Ni surface, consequently, generating the hybrid films. As expected, the hybrid films exhibit substantial opto-electrical and field electron emission properties superior to their individual counterparts. The finding suggests a promising route to hybridize the graphene with diverse nanomaterials for constructing novel hybrid materials with improved performances.