FeCl2-CVD production of carbon fibres with graphene layers nearly perpendicular to axis

We decomposed acetylene by chemical vapour deposition in presence of FeCl2 vapours, which react with carbon radicals without thermal decomposition (500 °C). This produced a large volume of wool-like product around the FeCl2 reservoir, composed of semi-crystalline carbon fibres, with high conversion rate (40 mass%). Fibres showed remarkable morphology, with iron nano-rings belting their centres and mirror symmetry. Fibres were mono or multi filament (each filament belted with metal). Semi-crystalline fibres were readily transformed by thermal treatment into a large-angle conical structure with turbostratic piling along fibre axis. These observations suggest a catalytic growth on the inner wall of iron rings.