High-density growth of vertically aligned carbon nanotubes with high linearity by catalyst preheating in acetylene atmosphere

Abstract

Vertically aligned carbon nanotubes (CNTs) with a high number density of 2 × 1011 cm-2 were successfully synthesized by catalyst-assisted thermal chemical vapor deposition using catalyst preheated in C2H2 atmosphere. The synthesized CNTs were found to possess high linearity and good crystallinity. The catalyst nanoparticles with a high number density and a narrow size distribution were efficiently formed by preheating in C2H2 as compared with those treated in H2 and He. The obtained results can be attributed to the decrease in the migration length of Fe catalyst due to the incorporation of carbon during the preheating process. © 2008 The Japan Society of Applied Physics.