Mechanical and electronic properties of a C/BN nanocable under tensile deformation

摘要

Atomistic simulations are performed to investigate the structural, mechanical and electronic properties of a coaxial C/BN nanocable under axial elongation using molecular dynamics. Our results show that the mechanism of the breaking process essentially differs from those for initial single-walled carbon and BN nanotubes. The formation of a carbon as well as a -C-B-N- atomic chain connecting two cable fragments before fracture is obtained, and due to such bridges the cable can be stretched until complete rupture up to epsilon(max) similar to 29% as compared with epsilon(max) similar to 23% for a single-walled carbon nanotube. After breakage the opposite tips of cable fragments form different individual atomic morphologies and compositions and can have promising potential as electron emitters. The Young moduli of the C/BN cable and C-NT are comparable. An analysis of the electronic structure shows that during tensile deformation the C/BN cable retains the basic electronic characteristics (metallic-like for the inner carbon nanotube and dielectric for the outer BN tube); however, the bandgap between the highest occupied N 2p and lowest unoccupied B 2p states decreases from 4.0 to 1.2 eV.