The properties and formation of nanotubes have been extensively studied, bu
t very few deal with the catalytic production mechanism of nanotubes. Two d
ifferent techniques, thermogravimetric analysis and UV-Raman, have been app
lied to analyse the carbon deposition by catalysed decomposition of acetyle
ne over an iron-based catalyst. The nature of the produced carbon materials
depends on reaction temperature. Also, TEM allows identification of carbon
nanotubes, encapsulated particles, and other nanostructures, while UV-Rama
n confirms its graphitic and graphite-like nature. (C) 2000 Elsevier Scienc
e Ltd. All rights reserved.