Synthesis and characterization of iron-included onion-like fullerenes

Iron-included Onion-like Fullerenes(OLFs) were formed by pyrolysis ferrocene and C,H, in H, and Ar streams through a cylindrical furnace with a temperature at 950 degrees C in their center. The resulting carbon structure morphology was influenced by different carrying gases. When proper hydrogen flow was used in the carring gas, the graphitic carbon on the surface of metal catalysts can be easily eached. This etching rate and the catalytic efficiency of metal are two competitive mechanisms in the graphitization processes, that is, when the etching rate of graphitic sheets dominates, iron-included OLFs are apparently the end product. XRD showed that the presenting metal particle is iron carbide. XRD patterns show that the presented metal particle is iron carbide. Raman scattering spectra show that the G peak of iron-included OLFs has slightly upshift from the position 1 582 cm(-1)(known for a pure graphite), which was interpreted as an influence of shell curvature. Hollow core OLFs can be obtained after the iron carbide particals were removed by annealing iron-included OLFs at 1 900 degrees C for 4 h.