Control of carbon nanotubes density through Ni nanoparticle formation using thermal and NH3 plasma treatment

We controlled the size and distribution of catalytic Ni nanoparticles to control the density and diameter of carbon nanotubes (CNTs). With an increase in plasma power from 30 to 90 W for Ni layer of 30 Angstrom, the average diameter of particles decreased from 157 to 58 nm due to an enhanced etching effect. Size and distribution of Ni nanoparticles varied by plasma power, pretreatment time and thickness of catalytic layer, resulting in the change in the density of grown CNTs. Density of CNTs reduced from I X 10(9) to 8 X 10(6) cm(-2), depending on the pre-treatment condition. (C) 2002 Elsevier Science B.V. All rights reserved.