Electronic properties of a silicon carbide nanotube under uniaxial tensile strain: a density function theory study

The electronic properties of an armchair (4,4) single-walled silicon carbide nanotube (SWSiCNT) with the length and diameter of 22.4 and 6.93 A, respectively under different tensile strains are investigated by density functional theory (DFT) calculation. The change of highest occupied molecular orbital and lowest unoccupied molecular orbital (HOMO–LUMO) gap of the nanotube has been observed during the elongation process. Our results show that the gap will significantly decrease linearly with the increase of axial strain. Two different slopes are found before and after an 11% strain in the profiles of the HOMO–LUMO gap. The radial buckling has been performed to investigate the radial geometry of nanotube. The partial density of states (PDOS) of two neighboring Si and C atoms of the nanotube are further studied to demonstrate the strain effect on the electronic structure of SiC nanotube. The PDOS results exhibit that the occupied states of Si atom and the unoccupied states of C atom are red-shifted and blue-shifted under stretching, respectively. Mulliken charge analysis reveals that Si and C atoms will become less ionic under the larger strain. The electron differences of silicon carbide nanotube (SiCNT) on tensile loading are also studied.