Experimental studies of the cap structure of single-walled carbon nanotubes

Carbon atoms forming the cap of a carbon nanotube are selectively removed through a technique that causes field evaporation during field emission. The resulting changes in the spatially resolved electronic structure are imaged in real time using field emission microscopy. We demonstrate that through repetitive field evaporation cycles, a variety of cap states can be produced on the same nanotube. We measure differences in the electrical properties due to the presence of different cap states. (C) 2003 American Vacuum Society. [DOI: 10.1116/1.155917].