Carbon nanotubes, nanofilaments and nanobeads by thermal chemical vapor deposition process

From commercial kerosene, straight and coiled nanotubes, nanofilaments and nanobeads are grown by suitably adjusting pyrolysis temperature and catalysts by the thermal chemical vapor deposition (CVD) technique. Nickel and iron facilitate the growth of straight and coiled nanotubes, respectively, at a temperature of 1000 degreesC. With an increase of pyrolysis temperature to 1100 degreesC, carbon nanobeads resulted in the presence of both the catalysts. Although, coiled nanotubes are formed at 900 degreesC in the presence of iron catalysts but nickel gives nanofilaments of diameter in the range 80-100 nm at the same temperature. The crystallinity and thermal properties are studied. (C) 2002 Elsevier Science B.V. All rights reserved.