Defect-driven room-temperature coalescence of double-walled carbon nanotubes

Room-temperature (RT) coalescence of double-walled carbon nanotubes has been observed for the first time. A combined pre-treatment of localized electron irradiation, Joule heating, and electromigration leads to the formation of large vacancy clusters, which can survive for tens of seconds during surface reconstruction. The dangling bonds of the edge atoms are highly reactive and thus promote the coalescence even at RT.