Effect of the Growth Temperature on the Diameter Distribution and Chirality of Single-Wall Carbon Nanotubes

Pulsed laser vaporization of a heated, Fe/Ni or Co/Ni catalyzed, carbon target in argon gas has been used to synthesize single-wall carbon nanotubes (SWNTs). Electron microscopy, x-ray diffraction, and Raman spectroscopy were all used to study the effect of the catalyst on the tube yield, and the evolution of the tube diameter distribution with increasing growth environment temperature $T$. By controlling the temperature in the range $780<T<1050\ifmmode^\circ\else\textdegree\fi{}\mathrm{C}$, we have been able to tune the diameter of the tubules from $\ensuremath{\sim}0.81$ to $\ensuremath{\sim}1.51\mathrm{nm}$. The threshold temperature for significant SWNT production was found to be $\ensuremath{\sim}850\ifmmode^\circ\else\textdegree\fi{}\mathrm{C}$.