Abstract
This study reports a novel, cost-effective and reproducible method of densifying carbon nanotubes into bundles during growth stage. This is achieved by utilizing Fe3O4 catalyst nanoparticles and microwave plasma-enhanced chemical vapor deposition. The grown CNTs were characterized using TEM, SEM and Raman spectrometer. The achieved site density of bundles is 5 x 10(9) m(-2), with an inter-bundle distance of 14 mu m and bundle height of 17 mu m. A qualitative investigation was carried out, and a possible densification mechanism was proposed.