Structural characterization of carbon nanofibers obtained by hydrocarbon pyrolysis

Carbon nanofibers with diameters of 80–100 nm were obtained by the pyrolytic method when a benzene solution containing ferrocene was used as a feedstock. A higher flow rate of carrier gas induced variations in the macro-morphology and also in the microstructure. The characteristics of these fibers were bundle formation, such as a macro-fibril, with a different tip morphology as compared with that of submicron vapor-grown carbon fibers (VGCFs), a small size of the hollow core, and a highly crystalline property in the as-grown state. Any amorphous carbon that was present was almost completely removed through an oxidization process. The sharp curvature caused by the small diameter prohibited perfect three-dimensional graphene stacking during the graphitization process. Even though this fiber has a similar distribution of diameters to that of submicron VGCFs, its crystalline property is very similar to that of carbon nanotubes.