Characterization of fullerenes and carbon nanoparticles generated with a laser-furnace technique

Laser ablation of a graphite rod and in situ separation of carbon soot by a temperature-gradient sublimation was systematically investigated using a laser-furnace apparatus. LD-TOF (laser desorption time-of-flight) mass spectra for the carbon deposits after separation show characteristic features of mass distributions mostly caused by the differences in size and structure. It was also found that some portions of the carbon deposits were strongly influenced by the experimental conditions such as the ambient temperature of an electric furnace. Laser Raman spectroscopy was also applied to deduce structural information of the carbon deposits. Furthermore, in order to characterize the laser ablation processes under exactly the same condition used for generating a high yield of fullerenes, we performed emission spectroscopic experiments by use of a high-speed video camera under several different conditions. Based on these experimental findings, the formation processes of carbon nanoparticles including fullerenes are discussed.