Preparation of carbon nanotubes with different morphology by microwave plasma enhanced chemical vapour deposition

In this work we present a part of our results about the preparation of carbon nanotube with different morphologies by using microwave plasma enhanced chemical vapour deposition MPECVD. Well aligned, curly, carbon nanosheets, coiled carbon sheets and carbon microcoils have been prepared. We have investigated the effect of the different growth condition parameters such as the growth temperature, pressure and the hydrogen to methane flow rate ratio on the morphology of the carbon nanotubes. The results showed that there is a great dependence of the morphology of carbon nanotubes on these parameters. The yield of the carbon microcoils was high when the growth temprature was 700 degrees C. There is a linear relation between the growth rate and the methane to hydrogen ratio. The effect of the gas pressure on the CNTs was also studied. Our samples were investigated by scanning electron microscope and Raman spectroscopy. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim