title: Effect of deposition pressure on the morphology and structural properties of carbon nanotubes synthesized by hot-filament chemical vapor deposition.
abstract: Hot-filament chemical vapor deposition has developed into an attractive method for the synthesis of various carbon nanostructures, including carbon nanotubes. This is primarily due to its versatility, low cost, repeatability, up-scalability, and ease of production. The resulting nano-material synthesized by this technique is dependent on the deposition conditions which can be easily controlled. In this paper we report on the effect of the deposition pressure on the structural properties and morphology of carbon nanotubes synthesized by hot-filament chemical vapor deposition, using Raman spectroscopy and high-resolution scanning electron microscopy, respectively. A 10 nm-thick Ni layer, deposited on a SiO2/Si substrate, was used as catalyst for carbon nanotube growth. Multi-walled carbon nanotubes with diameters ranging from 20-100 nm were synthesized at 500 degrees C with high structural perfection at deposition pressures between 150 and 200 Torr. Raman spectroscopy measurements confirm that the carbon nanotube deposit is homogeneous across the entire substrate area.
authors.affiliation: National Centre for Nanostructured Materials, Council for Scientific and Industrial Research, P.0. Box 395, Pretoria 0001, South Africa.
authors.forename: C J
authors.initials: CJ
authors.lastname: Arendse
authors.forename: G F
authors.initials: GF
authors.lastname: Malgas
authors.forename: M R
authors.initials: MR
authors.lastname: Scriba
authors.forename: F R
authors.initials: FR
authors.lastname: Cummings
authors.forename: D
authors.initials: D
authors.lastname: Knoesen
mesh_terms: D003460:Crystallization / Q000379:methods*; D005740:Gases / Q000737:chemistry; D006358:Hot Temperature; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D036103:Nanotechnology / Q000379:methods*; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D011312:Pressure; D013499:Surface Properties
chemical_list: D005740:Gases; D046911:Macromolecular Substances; D037742:Nanotubes, Carbon