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Electro-mechanical Properties of Carbon Nanotubes: Effect of Small Tensile and Torsional StrainsWe present a simple picture to calculate the bandgap ($E_g$) of carbon nanotubes (CNT) in the presence of uniform torsional and tensile strain ($\sigma$). We find that under tensile strain, $ absolute value of dE_g/d\sigma$ of zig-zag tubes is approximately equal to $3t_0$, where $t_0$ is the hopping parameter. Further, $ absolute value of dE_g/d\sigma$ decreases as the chirality changes to armchair, where it takes the value zero. The sign of $dE_g/d\sigma$ follows the $(N_x-N_y) *mod 3$(equal to - 1, 0 and +1) rule. In contrast to the above, we show that under torsional strain, $absolute value of dE_g/d\sigma$ of armchair tubes is approximately equal to $3t_0$ and continually decreases as the chirality changes to zig-zag, where is takes a small value. The sign of $dE_g/d\sigma$ again follows the $(N_x-N_y)*mod 3$ rule. Finally, we predict a change in the sign of $dE_g/d\sigma$ as function of strain, corresponding to a change in the value of $q$ that corresponds to the bandgap minimum.
Document ID
20020070285
Acquisition Source
Ames Research Center
Document Type
Conference Paper
Authors
Anantram, M. P.
(NASA Ames Research Center Moffett Field, CA United States)
Yang, Liu
(NASA Ames Research Center Moffett Field, CA United States)
Han, Jie
(NASA Ames Research Center Moffett Field, CA United States)
Liu, J. P.
(NASA Ames Research Center Moffett Field, CA United States)
Saini, Subhash
Date Acquired
August 20, 2013
Publication Date
January 1, 1999
Subject Category
Solid-State Physics
Meeting Information
Meeting: American Physical Society Meeting
Location: Atlanta, GA
Country: United States
Start Date: March 20, 1999
End Date: March 26, 1999
Funding Number(s)
CONTRACT_GRANT: NAS2-14303
PROJECT: RTOP 519-40-12
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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