Electromechanical effects in carbon nanotubes:Ab initioand analytical tight-binding calculations
Year: 2003
Type: article
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 nonmonotonic 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 $|e|/\mathrm{atom}$ for graphene and between 0.1 and $0.3|e|/\mathrm{atom}$ for the metallic nanotubes studied. (3) Semiconducting CNT's with small diameters $(d\ensuremath{\lesssim}20\mathrm{\AA{}})$ always expand upon hole injection. (4) Semiconducting CNT's with large diameters $(d\ensuremath{\gtrsim}20\mathrm{\AA{}})$ display a behavior intermediate between those of metallic and large-gap CNT's. (5) The strain versus extra charge displays a linear plus power-law behavior, with characteristic exponents for graphene, metallic, and semiconducting CNT's. All these features are physically understood within a simple tight-binding total-energy model.
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W3141239301