| Abstract
| - Nitrogen-doped carbon nanotubes were grown vertically aligned on the iron nanoparticles deposited on siliconsubstrates, by thermal chemical vapor deposition of methane/ammonia and acetylene/ammonia mixtures inthe temperature range 900−1100 °C. The concentration of the nitrogen atoms has been controlled in therange 2−6 atomic %, by the flow rate of ammonia. All nanotubes exhibit a bamboo-like structure over thistemperature range. The growth rate is insensitive to this nitrogen content, but the structure is strongly dependenton it. As the nitrogen content increases, the thicker compartment layers form uniformly at a regular distanceand the relative amount of crystalline graphitic sheets is notably reduced. Electron energy-loss spectroscopyreveals the higher nitrogen concentration and the lower crystallinity for the compartment layers compared tothe wall. The growth of nitrogen-doped carbon nanotubes has been explained using a base growth mechanismproposed for carbon nanotubes. We suggest that the nitrogen doping would produce more flexible compartmentlayers connecting the wall under a less strain.
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