Abstract
Multiwall and singlewall carbon nanotubes were synthesized on Fe-Co/CaCO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> and a Fe-Co/MgO catalyst systems, respectively, by using two different catalytic chemical vapor deposition methods, external furnace (EF) heating and radio frequency (RF) excitation. The carbon nanotubes synthesized with radio frequency excitation have a smaller outer diameter, fewer layers (smaller outer/inner diameter ratio), and better crystalline properties, compared to the nanotubes grown with external furnace heating. The radio frequency process was found to be responsible for a faster growth rate of the carbon nanotubes over longer periods of time due to a higher localized heating. These findings can be explained by the skin currents induced in the metallic catalytic clusters, which keep the catalysts active for longer periods of time and diminishes the amount of non-crystalline carbon formed in the synthesis process. A direct correlation between the frequency of the electromagnetic field and the morphology of the nanotubes was also found.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.