2014 Volume 55 Issue 3 Pages 461-465
The behavior of gold chloride (AuClx) encapsulated within the inner space of a single-wall carbon nanotube (SWCNT) was investigated under electron beam (e-beam) irradiation and high temperatures. Analysis of the pristine specimen by transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), and Raman spectroscopy show that AuClx is encapsulated within the SWCNTs as a dilute disordered structure. In situ TEM observation of the specimen under e-beam irradiation shows that, within the SWCNTs, AuClx is reduced to a crystalline Au nanowire (AuNW). The AuNW drifts significantly within the SWCNT during the reduction. At high temperatures (>673 K), in situ TEM shows that the AuNW oscillates intermittently at a frequency of ∼1.1 s−1 and amplitude of ∼60 nm. Raman spectroscopy and EDX suggest that these phenomena are caused by an increase in the internal gas pressure in the SWCNTs because the decomposition of AuClx by e-beam irradiation or heat treatment produced chlorine (Cl2) gas.