In-Situ Investigation on Structure Transformation of Single-walled Carbon Nanotubes

The in-situ structure transformations by high-temperature energy beam in single-walled carbon nanotubes (SWCNTs) in real-time are investigated by experiment and molecular dynamics (MD) simulation. Experimental results showed that electron beam irradiation dramatically changed the size and structure of SWCNTs, leading defects, fracture, fusion, amorphization, evaporation and so on. The mechanism that causes these phenomena in experiments are explored and explained by using MD simulation. Thermodynamic and energy properties such as Lindeman index, potential energy plots and radial distribution function obtained by MD simulations revealed that 4200 K (+/- 100 K) is the critical temperature for the damage or premetling of (6,6) SWCNTs, which are in solid-liquid coexistence stage between 4200 K and 4800 K. Once the temperature exceeded 4800 K, the SWCNTs will be dismembered and vaporized. This work is significant to establish a link between SWCNTs transformations and its temperature and provides a support for welding between SWCNTs and manufacturing SWCNT-based devices.