Comparative study of the carbon nanotubes grown over metallic wire by cold plasma assisted technique

Carbon nanotubes were grown on metallic wire by a very simple technique called as cold plasma chemical vapor deposition. In this technique carbon nanotubes were grown directly over the catalyst-supported wire by resistive heating in hydrocarbon atmosphere at above 700 °C. The comparative studies of the properties of the nanotube were carried out by varying different parameters like: growth time, growth temperature, growth pressure, catalyst and its concentrations. The effect of plasma created by applying additional bias is also discussed. The growth time has the influence on the density of the nanotube films but the length and diameter of the nanotubes also changes at low growth time region. With the increase of growth temperature, nanotube diameter and periodicity of the spiral nanotube increases. The growth pressure and catalyst concentrations have only influence on the density of the nanotube. Additional plasma creations around the wire by applying bias reduce the density of the spiral structures and if exists its periodicity increases.