Room-temperature coalescence of double-walled carbon nanotubes was observed for the first time. A combined pre-treatment of localized electron irradiation, Joule heating, and electromigration led to the formation of large vacancy clusters, which could survive for tens of seconds during surface reconstruction. The dangling bonds of the edge atoms were highly reactive and thus promote the coalescence even at room temperature.

Defect-Driven Room-Temperature Coalescence of Double-Walled Carbon Nanotubes. A.Nie, P.Wang, H.Wang, S.X.Mao: Nanotechnology, 2010, 21[24], 245302