Electromechanical Effects in Carbon Nanotubes
Abstract
We perform ab initio calculations of charged graphene and single-wall carbon nanotubes (CNTs). A wealth of electromechanical behaviors is obtained: (1) Both nanotubes and graphene expand upon electron injection. (2) Upon hole injection, metallic nanotubes and graphene display a non-monotonic behavior: Upon increasing hole densities, the lattice constant initially contracts, reaches a minimum, and then starts to expand. The hole densities at minimum lattice constants are 0.3 |e|/atom for graphene and between 0.1 and 0.3 |e|/atom for the metallic nanotubes studied. (3)Semiconducting CNTs with small diameters (d <~ 20 A) always expand upon hole injection; (4) Semiconducting CNTs with large diameters (d >~ 20 A) display a behavior intermediate between those of metallic and large-gap CNTs. (5) The strain versus extra charge displays a linear plus power-law behavior, with characteristic exponents for graphene, metallic, and semiconducting CNTs. All these features are physically understood within a simple tight-binding total-energy model.
Keywords
Cite
@article{arxiv.cond-mat/0211381,
title = {Electromechanical Effects in Carbon Nanotubes},
author = {M. Verissimo-Alves and Belita Koiller and H. Chacham and R. B. Capaz},
journal= {arXiv preprint arXiv:cond-mat/0211381},
year = {2009}
}
Comments
Submitted to Physical Review Letters on May 23rd 2002