Transition between 'base' and 'tip' carbon nanofiber growth modes

Carbon nanofibers (CNFs) have been synthesized by catalytically controlled dc glow discharge plasma-enhanced chemical vapor deposition (PECVD). Both base-type and tip-type nanofibers have been produced on identical substrates. We have observed a sharp transition between these two growth modes by controlling the kinetics of the growth process without changing the substrate and catalyst materials. This transition is brought about by changing the parameters used in the deposition process such as the flow ratio of the carbonaceous and etchant gasses and others, This study of the initial growth stages as a function of time for both regimes provides a basis for a model of the growth mode transition. (C) 2002 Published by Elsevier Science B.V.