Irradiation of CW-CO2 laser on a powder target. Formation of fullerene film from graphite powder

Extracts of impact breccia samples from Sudbury, Gardnos, and Ries impact craters and the effects of aggregation on C60 detection

“…The most widely used analytical techniques are high-pressure liquid chromatography (HPLC) and laser desorption mass spectrometry (LDMS). Both have potential drawbacks; HPLC may suffer from misinterpretations caused by compounds with identical retention times (although this effect can be reduced by the use of preseparation or multiple HPLC columns), whereas laser desorption has been shown to create fullerenes under certain circumstances (Kasuya et al, 2001;Kano et al, 2003). In several cases C 60 was detected in samples using LDMS but was not observed with HPLC, even when LDMS results suggest C 60 concentrations well above the level of HPLC detectability and show no evidence of laser-induced fullerene formation (Becker et al, 1994a;Becker et al, 1994b;Heymann, 1995;Heymann, 1997;Heymann et al, 1999).…”

Anticorrelated formation of fullerenes and polyynes upon laser ablation of graphite under various concentrations of hydrogen sources

“…Indeed, irradiation with much stronger lasers, a long-pulse (500 ms, 1 Hz) CO 2 laser of 20 kW/ cm 2 and a 4.5-kW CW CO 2 laser, succeeded in forming fullerenes. In these cases, the laser heating of the reaction field was considered to be essential [16,17]. Although the laser power used in the present study was much lower, surface temperature was an important factor.…”