This paper reports the growth of carbon nanotubes by catalytically cracking ethylene in the presence of the supported catalyst doped with rare earth oxide. The addition of rare earth composition noticeably affects the morphology and the yield of carbon nanotubes. Comparative results of the carbon nanotubes synthesized with or without rare earth additions indicate that the addition of rare earth effectively increases the yield of carbon nanotubes of about 250% and decreases its formation temperature. The diameter of carbon nanotubes...
