Temperature effect on the growth of carbon nanotubes using thermal chemical vapor deposition

Vertically aligned carbon nanotubes (CNTs) are grown on iron-deposited silicon oxide substrates by thermal chemical vapor deposition (CVD) of acetylene gas at the temperature range 750-950°C. As the growth temperature increases from 750°C to 950°C, the growth rate increases by four times and the average diameter also increases from 30 nm to 130 nm while the density decreases by a factor of about two. The relative amount of crystalline graphitic sheets increases progressively with the growth temperature and a higher degree of crystalline perfection can be achieved at 950°C. This result demonstrates that the growth rate, diameter, density, and crystallinity of CNT can be controlled with the growth temperature.