The radial breathing mode of carbon nanotubes

Abstract

We report an extensive set of results for the radial breathing modes (RBM) of infinite and finite length single walled carbon nanotubes using the second generation reactive empirical bond order potential (REBO) developed by Brenner et al. As expected, the frequency, ν of the RBM is inversely proportional to the nanotube radius, R ₀, \nu = \alpha /R_{0}. We find two different linear fits to the data, one for zigzag tubes (3.25 THz nm) and one for armchair tubes {\rm ( \alpha = 3.18 \hspace{0.167em} THz \hspace{0.167em} nm).} For finite tubes, the RBM rapidly approaches the infinite length value for nanotubes greater than 5 nm in length.

Keywords:

• Reactive empirical bond order potential
• Radial breathing mode

Acknowledgements

M J Longhurst thanks the National Physical Laboratory, Teddington UK for a CASE award.

Notes

moldsim is a molecular dynamics simulation package written in C++ by Matthew Longhurst, Imperial College. For more information see www.MOLDSIM.com.

VMD is a free molecular visualisation program developed by the Theoretical and computational Biophysics group of the University of Illinois—http://www.ks.uiuc.edu/Research/vmd/.

POV-Ray is a free ray tracing tool—www.povray.org.