Vapor-grown carbon nanofibers synthesized from a Fe2O3–Al2O3 composite catalyst

Vapor-grown carbon nanofibers (CNFs) were synthesized from a Fe2O3-Al2O3 composite ceramic catalyst. It was revealed that the CNF constructions and structures depended on the catalyst phase. Fe2O3 solid solution and FeAlO3 catalysts synthesized fine CNFs with diameter of 10–15 nm. These CNF structures were similar to those of MW-CNTs. Notably, the FeAlO3 catalyst could synthesize aligned CNF structures. The secondary phase precipitated from FeAlO3 in the specific crystal direction and this precipitation induced the cleavage fracture of FeAlO3 grain during CNF synthesis. As a result, CNFs grew on the specific plane and aligned in one direction.