Temperature-dependent brittle-ductile transition of α-graphyne nanotubes under uniaxial tension

As a novel one-dimensional full-carbon allotrope, the tensile property of α-graphyne nanotubes (α-GNTs) under different temperatures was studied with reactive molecular dynamics method. A very interesting phenomenon temperature-dependent brittle-ductile transition for carbon nanomaterials found no matter what chirality α-GNT is. The shows brittle behavior an ultimate strain ~0.2 at relatively low temperatures. When temperature is higher than critical temperature, it exhibits ductile ~0.4. first decreases and then increases increase temperature. fundamental mechanism such revealed, which mainly due to thermal activation energy-controlled microstructure evolution. Beyond atomic structures around some hexagonal corners in α-GNTs would recombine through continuous formation annihilation new triangular structures. Such totally from Stone-Wales defect-induced (Nardelli et al, Phys. Rev. Lett, 1998, 81(21): 4656). influence on other physical parameters α-GNTs, as Young’s modulus, yield strength, stress, also systematically studied. results this paper, especially mechanism, be great help subsequent study application α-GNTs.