Molecular Dynamics Simulation of Damage to Coiled Carbon Nanotubes under C Ion Irradiation

The stability of coiled carbon nanotubes under C ion irradiation is investigated by molecular dynamics simulations.The defect statistics shows that small curvature coiled carbon nanotubes have better radiation tolerance than normal straight carbon nanotubes.To understand the effect of the curvature on defect production,the threshold displacement energies for the upper and lower walls,as well as those for the side parts,are calculated.The results show that the lower wall has better radiation tolerance than the upper wall.For the upper wall,a small increase in the curvature of nanotube axis gives rise to an increase in the radiation tolerance and then a decrease with the curvature becomes larger.However,for the lower wall,as the curvature of the nanotube axis increases,the radiation tolerance increases as the bonds compressed slightly in our simulation.