CVD synthesis of coal-gas-derived carbon nanotubes and nanocapsules containing magnetic iron carbide and oxide

Iron carbide–oxide filled carbon nanotubes and nanocapsules (CNCs) are separately synthesized by catalytic chemical vapor deposition of coal gas at 950 °C with ferrocene as catalyst. The products are examined using transmission electron microscopy and XRD techniques, showing that nanosized iron carbide–oxide particles are encapsulated by well ordered carbon layers. Magnetic moment measurement reveals that these carbon encapsulated iron carbide–oxides exhibit large magnetic coercivity at room temperature. It has been found that the filled CNCs are corrosion-proof and stable in hydrochloric acid. The effect and interaction between different gaseous components in the coal-gas during the formation of magnetic iron carbide–oxide filled carbon nanostructures are discussed.