In situ transmission electron microscopy of field-emitting bundles of double-wall carbon nanotubes

The dynamic behavior and degradation of carbon nanotube field emitters were studied by in situ transmission electron microscopy. The carbon nanotube, emitters used for the study were double-wall nanotubes (DWNTs) produced by arc discharge. The DWNTs formed bundles, each of which contained about seven DWNTs. The splitting of a bundle into two branches, forming a Y shape, accompanied by an abrupt increase of emission current, was observed in real time. The shortening of bundles, presumably due to Joule heating, was also observed. The maximum emission current from a bundle just before its sublimation was at least 10 mu A, which corresponds to 1.4 mu A per single DWNT.