Structural, elastic, and electronic properties of deformed carbon nanotubes under uniaxial strain

We report structural, elastic, and electronic properties of selected, deformed, single-wall carbon nanotubes under uniaxial strain. We utilized a generalized gradient approximation potential of density functional theory and the linear combination of atomic orbital formalism. We discuss bond-lengths, tubule radii, and the band gaps as functions of tension and compression strain for carbon nanotubes (10, 0), (8, 4), and (10, 10) which have chiral angles of 0, 19.1, and $30\mathrm{deg}$ relative to the zigzag direction. We also calculated the Young’s modulus and the in-plane stiffness for each of these three nanotubes as representatives of zigzag, chiral, and armchair nanotubes, respectively. We found that these carbon nanotubes have unique structural properties consisting of a strong tendency to retain their tubule radii under large tension and compression strains.

Figure 1

Bond lengths and tube radius as functions of compression and tension strain $\epsilon$ for (10,0) nanotube. Each length is scaled to its unstrained length.

Figure 2

Bond lengths and tube radius as functions of tension strain and compression strain $\epsilon$ for (8,4) nanotube. Each length is scaled to its unstrained length.

Figure 3

Band gaps of indicated carbon nanotubes as functions of compression and tensile strain.