Carbon nanotubes growth by chemical vapor deposition using thin film nickel catalyst

The results of a study of multi-walled carbon nanotubes (CNTs) growth using two different chemical vapor deposition (CVD) techniques (low pressure plasma enhanced and atmospheric pressure thermal CVD) are presented. Thin films of Ni were used as a catalyst. The process of nickel nanoparticles formation during thermal pre-treatment of the catalyst was studied using AFM in a non-contact mode. The effect of different gases used for the catalyst surface pre-treatment (N-2, H-2 or NH3) was also analyzed. Higher density of nucleation and growth was obtained using hydrogen and ammonia. The results show the critical importance of the initial stage of nanotubes nucleation. (C) 2004 Elsevier B.V. All rights reserved.