| This thesis covers the controlled growth of carbon nanotubes/nanofibers using two different Chemical Vapor Deposition (CVD) methods employing various substrates. Thin metal films and metal based solution were used as catalyst to grow the Carbon Nano Tubes (CNTs) on various substrate surfaces. The subsequent studies of the morphology of the carbon structures grown by CVD methods revealed an influence of the deposition temperature and the catalyst material on the properties of the carbon structures. Scanning electron microscopy and Raman spectroscopy were used to investigate the structures in details.; It was found that the increase in substrate (heater) temperature and CVD run time in hot filament CVD lead to the higher growth yield and new morphologies (coiled nanotubes, vertically aligned CNTs). Use of Co and Fe(NO3) 3 as catalytic on silicon and quartz substrates for atmospheric pressure CVD growth resulted in formation of Y-junction and multiple Y-junction carbon nanotubes. Different confined geometries, such as quartz substrate with microchannel, fused silica (FS) tube and anodized alumina membrane (AAO) have been tested for the growth of carbon nanostructures. |
