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NUE 2003-2004

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NSF NSE

Thermal Chemical Vapor Deposition of Carbon Nanotubes

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Catalyst surface melting

Multiwalled Nanotubes - Tip Growth Model

Thermal Chemical Vapor Deposition: The growth species is generated by dissociative adsorption of hydrocarbon on catalyst surface. Nanotubes are formed via the Vapor-Liquid-Solid (VLS) mechanism.

  • Substrate with catalyst thin film
  • Substrate pretreatment induces formation of nanoparticle catalyst
  • Catalyst surface melting on a high temperature substrate. We propose a solid core model.
Adsorption of hydrocarbon molecules
  • Adsorption of hydrocarbon molecules (C2H2 in this case) on the catalyst surface.
  • Dissociation of H atoms from the hydrocarbon molecules (dissociative adsorption).
Diffusion of carbon into catalyst
  • Diffusion of carbon into the catalyst and readsorption of the hydrocarbon on the catalyst surface.
  • Saturation of carbon in catalyst particle.
Formation of carbon nanotubes

Segregation of carbon to form carbon nanotubes.

Hollow nanotube is formed

No segregation directly under the core. A hollow nanotube is formed.

About This Animation

Investigator:

Dr. Yoke Khin Yap
Department of Physics, Michigan Technological University
Houghton, Michigan

Animator:

Dr. Susan E. Hill

© 2004 Michigan Technological University

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