A theoretical analysis of the effect of a Stone-Thrower-Wales defect on the stability of carbon nanotube-based nanorings

Molecular dynamics simulations are performed to study the effect of the presence of the Stone-Thrower-Wales defect on the stability of carbon nanorings. It is found that nanoring stability can be enhanced or worsened depending on the defect position and configuration as a result of the coupling between the defect strain field and the nanoring bending strain field. The nanoring stability deteriorates if the defect compression (tension) strain superimposes the nanoring bending compression (tension) strain, while the stability may be enhanced if the defect compression (tension) strain alleviates the nanoring bending tension (compression) strain. For certain defect positions and configurations, a zigzag nanoring is able to spontaneously rotate along its own tubular axis, allowing the defect compression (tension) strain to reduce the nanoring bending tension (compression) strain, thus enhancing the stability. However, an armchair nanoring does not exhibit this rotation.