Aligned Carbon Nanotubes growth on various .nanostructured tantalum nitride films deposited by high power pulsed magnetron sputtering

摘要

Because of their unique structure, carbon nanotubes CNT are expected to bring significant breakthroughs in the electronic and mechanical engineering of materials. In the latest years important scientific advances have taken place .in the fabrication of aligned multiwall CNTs by chemical vapor deposition. Numerous studies have been done for the understanding of the CNTs growth by CCVD. The models nowadays adopted decompose the growth in 3 stages: the decomposition of the carbon precursor on the catalytic nanoparticles, the diffusion of C atoms inside this particle or just at the surface of the metallic particle, and finally a phase separation in which graphene cylinders precipitate at the surface of the catalytic particle [ 1 ]. The catalytic particle nature then depends on exchanges between the atoms of the substrate (Si, SiOx, buffer, carbon from the fiber...) and the miscibility of carbon in that particle; in particular, the growth of CNTs by CCVD at medium range temperature (600-900°C) has been tested on various materials, and has been shown unfavorable on metals, glass, ceramic or carbon fibers. The current option is to uniformly coat the fiber or metal before the CCVD process.The control of the growth on specific substrate may be resolved by using a mastered barrier layer (composition, nanostructure, roughness....) between the substrate and the CNTs, which interact with the catalyst.