First-principles study of the (2,2) carbon nanotube

Body‐Centered Tetragonal C16: A Novel Topological Node‐Line Semimetallic Carbon Composed of Tetrarings

“…This is caused by the higher ring strain in tetrarings . We also note that bct‐C 16 is not only more stable than some theoretically predicted carbon allotropes (e.g., T‐carbon and penta‐graphene), but also energetically more favorable than some experimentally synthesized carbon phases (e.g., C 20 fullerene and the smallest carbon nanotube CNT(2,2)), implying that the bct‐C 16 could be synthesized. Figure b displays the phonon spectra of bct‐C 16 at zero pressure, where the absence of imaginary frequencies throughout the entire BZ implies that bct‐C 16 is dynamically stable.…”

Self-assembled ultrathin nanotubes on diamond (100) surface

“…This elongation is the result of the small radius of the tube: geometric constraints lead to excessively bent sp 2 hybridization. Tube radius increases in the series of arrays from TA1 to TA3, with a single tube in TA3 resembling an isolated (2,2) CNT 27 (Fig. 1d), the smallest nanotube yet observed.…”

Electronic and structural properties of carbon nanotubes modulated by external strain

“…23,24 Recently, ultra small (2, 2) and (3, 0) CNTs were verified to exist with stable mechanical structures as a SWCNT or being formed inside a multiwalled carbon nanotubes (MWCNTs) at room temperature. [25][26][27][28] Relative to CNTs of a large tube diameter, these ultra small nanotubes exhibit the unusual characteristic of excellent field emission properties due to their large curvature effect. Moreover, since the mechanical deformations are notable during the process of building CNT-based devices, it is of interest and important to understand the electronic properties of strained CNTs in order to have a complete understanding of how individual CNTs behave under uniaxial strain.…”