Tensile behaviors investigation of SWCNT-Ni with vacancies

In this work, the second-generation Brenner reactive empirical bond-order potential is adopted in a series of molecular dynamics simulation which investigate the mechanical properties under tensile loading of (6,6) armchair single-walled carbon nanotube(SWCNT) and single-walled carbon nanotube coated with nickel atoms(SWCNT-Ni). To assess the influence of temperature upon the mechanical properties of and SWCNT and SWCNT-Ni, the simulation process is repeated at a range of temperature at 300K, 500K and 700K, and the stress-strain curves are derived. At the same time, different scale vacancies of SWCNT-Ni including 0%, 0.42% and 0.83%, correspond to 0, 2 and 4 vacancies respectively, at 300K, 500K and 700K are also considered. Mechanical properties of SWCNT-Ni with vacancies including tensile strength and tensile failure strain are obtained. Meanwhile the failure stress and failure strain of SWCNT-Ni and SWCNT are compared at 300K, 500K and 700K. The results verify that tensile strength and tensile failure of all the three models would decrease with the temperature rising. When SWCNT is coated with nickel atoms, failure stress and failure strain would be reduced greatly. The vacancies would degrade the mechanical properties. In short, the mechanical properties are mainly dominated by three factors: the thermal fluctuation, the activity of carbon atoms with dangling bond and C-Ni interactions.