Log Number: 70
Abstract Submitted to the NT-99-Logo NANOTUBE-99 Workshop:

Mechanical Properties and Transport in Carbon Nanotubes

J. Bernholc, M. Buongiorno Nardelli, J.-L. Fattebert, D. Orlikowski, R. Roland and Q. Zhao

NC State University, Raleigh, NC 27695-8202
Contact e-mail: bernholc@ncsu.edu

High strain conditions can lead to a variety of atomic transformations, often occurring via successive bond rotations. The barrier for the rotation is dramatically lowered by strain, and ab initio results for its strain dependence will be presented. While very high strain rates must lead to breakage, (n,m) nanotubes with n, m < 14 can display plastic flow under suitable conditions. This occurs through the formation of a 5-7-7-5 defect, which then splits into two 5-7 pairs. The index of the tube changes between the 5-7 pairs, potentially leading to metal-semiconductor junctions. A different way to induce transformations is through addimers, which can help form metallic quantum dots in a semiconducting nanotube.

We have also computed quantum conductances of strained tubes, defects, and nanotube junctions. The results show that the defect density and the contacts play key roles in reducing the conductance at the Fermi energy, while bending and mechanical deformations affect differently the conductance of achiral and chiral nanotubes. Our results are in good agreement with recent experimental data.

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Last modification:   1999.07.15 (Thursday) 11:31:07 EDT