Growth of aligned carbon nanotubes with controlled site density

Pulse-current electrochemical deposition has been used to prepare Ni nanoparticles that are used as the catalysts for the growth of aligned carbon nanotubes. The nucleation site density of the Ni nanoparticles was controlled by changing the magnitude and duration of the pulse current. The aligned carbon nanotubes from the nickel nanoparticles were grown by plasma enhanced hot filament chemical vapor deposition. The site density of the aligned carbon nanotubes varied from 10(5) to 10(8) cm(-2). The achievement of controlling the site density is significant for applications of carbon nanotubes as field emitters, nanoelectrodes array, etc. (C) 2002 American Institute of Physics.