Structural characterization of carbon nanofibers obtained by hydrocarbon pyrolysis

Carbon nanofibers with diameters of 80-100 nm were obtained by the pyrolyti c method when a benzene solution containing ferrocene was used as a feedsto ck. A higher flow rate of carrier gas induced variations in the macro-morph ology and also in the microstructure. The characteristics of these fibers w ere bundle formation, such as a macro-fibril, with a different tip morpholo gy 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 re moved through an oxidization process. The sharp curvature caused by the sma ll diameter prohibited perfect three-dimensional graphene stacking during t he graphitization process. Even though this fiber has a similar distributio n of diameters to that of submicron VGCFs, its crystalline property is very similar to that of carbon nanotubes. (C) 2001 Elsevier Science Ltd. All ri ghts reserved.