Vapor-deposited carbon, mechanical

Table 2.57 Representative Mechanical Properties of LTI, Glassy, and Vapor-Deposited Carbons (3)...

Figure 8.14 Mechanism of fiber growth. (1) Solid catalyst particle. (2) Short filament having grown on a solid particle. (3) Short filament on the liquid particle. (4) Rapid lengthening. (5) Fiber. Source Reprinted with permission from Gadelle P, The growth of vapor-deposited carbon fibres, Cartoon Fibers Filaments and Composites, Figueiredo JL, Bernardo CA, Baker RTK, Hiittinger KJ eds., Kluwer, Dordrecht, 115, 1990. Copyright 1990, Springer.

Popov, C., Zambov, L. M., Plass, M. R, and Kulisch, W., Optical, Electrical and Mechanical Properties of Nitrogen-rich Carbon Nitride Films Deposited by Inductively Coupled Plasma Chemical Vapor Deposition," Thin Solid Films, Vol. 377-378,2000, pp. 156-162. 

Figure 3.16 Different steps in the fabrication of MWNT nanoelectrode arrays, (a) metal film deposition, (b) catalyst deposition, (c) plasma-enhanced chemical vapor deposition for CNT growth, (d) dielectric encapsulation with Si02, (e) planarization with a chemical mechanical polishing to expose the ends of the carbon nanotubes, (f) electrochemical characterization. Readapted from Ref [6].

The mechanism of nanotube formation in chemical vapor deposition features characteristics rather distinct from those found for the synthesis by arc discharge or laser ablation. Contrary to the latter, a solution of small carbon clusters in and subsequent diffusion through catalyst particles play a minor role in the deposition from the gas phase. The employed hydrocarbons decompose directly on the surface of the catalytic particle. The carbon, therefore, becomes immediately available for nanotube growth. 

To address this problem, Monte Carlo simulations [32] and MD smdies [33-37] have been carried out before, aU of them using reactive empirical bond-order (REBO) Tersoff-type [38,39] interatomic carbon-carbon potentials developed originally for studying the vapor deposition of diamond [40,41]. Unlike traditional molecular mechanics force fields, the REBO potential allows for the formation and dissociation of covalent chemical bonds by determination of next neighbors and on-the-fly switching... 

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