Synthesis of carbon tubule nanocoils in high yield using iron-coated indium tin oxide as catalyst

We have synthesized carbon coils of nanometer-scale size by catalytic thermal chemical vapor deposition. The catalyst used is iron-coated indium tin oxide and the carbon source is acetylene. The yield of carbon coils is over 95% at a growth temperature of 700 degreesC. The carbon coil usually consists of two or more carbon tubules and each of them grows with its own diameter and pitch. The external diameters of the coils are from several tens to several hundreds of nanometers. It is found that iron plays an important role in the growth of carbon nanotubes, while indium, tin, oxygen, and/or their alloys are necessary in the formation of the coils.