Chemical vapour deposition - a promising method for production of different kinds of carbon nanotubes

Carbon nanostructures (fibres, multi and single walled tubes) have been syn thesized by catalytic chemical vapour deposition. The catalyst material, de position temperature and the used hydrocarbon are the main parameters respo nsible for the formation of the desired structure. In dependence on these p arameters and by optimising the deposition process nanofibres with herringb one structure and tubular multiwalled nanotubes were deposited in large amo unts and high purity. In the case of single wall nanotubes synthesis an aft ertreatment and process is absolutely necessary to obtain material with hig h percentage of tubes. Layers of disordered and aligned multiwalled nanotub es were deposited on oxidised silicon substrates coated with thin sputtered metal layers (Co, permalloy) by using the micro-wave assisted plasma CVD p rocess or the bias supported hot filament CVD method. The latter method all ows relatively low deposition temperatures (550 - 750 degreesC). The obtained carbon modifications were characterised by scanning and transm ission electron microscopy. Furthermore, the electron field emission of the CNT's layers were investigated.