Acetylene 2 Acetylene decomposition Amorphous carbon 2 Carbon nanotubes 2 Catalysts 2 Chemical vapor deposition 2 Compact coatings 2 Decomposition 2 Flow rate 2 Gas compositions 2 Iron catalysts 2 Multi-walled carbon nanotubes (MWCNTs) 2 Nanoparticles 2 Scanning and transmission electron microscopy 2 Scanning electron microscopy 2 Thermal analysis 2 Thermoanalysis 2 X ray diffraction 2 X-ray diffraction 2