Synthesis of carbon nanotubes and iron oxide nanoparticles in MW plasma torch with Fe(CO)5 in gas feed

The MW plasma torch (2.45 GHz) in the mixture of CH4/H2/Ar (42/430/1540 sccm) with added Fe(CO)5vapors was used for the synthesis of iron oxide nanoparticles and carbon nanotubes. The particles with well-defined facets consisting of Fe3O4 and image-Fe2O3 and self-assembled into long chains were produced at the power of 360 W. At higher power of 440–460 W the deposit contained significant amount of multi-walled carbon nanotubes covered by iron oxide nanoparticles. The diameter of CNTs was 8–20 nm. The particles had Fe3O4 and/or image-Fe2O3 cores of spherical shape covered by a thin layer of carbon.