Laser nanoablation of graphite in argon atmosphere

The results of comparative studies of laser ablation of highly oriented pyrolytic graphite in air and in an inert medium upon exposure to nanosecond pulsed laser irradiation with an energy density in the range E = 0.4 − 3 J/cm2 are presented. It is found that the nanoablation mode is established below the evaporative ablation threshold (E < Ea ≈ 1 J/cm2) in both cases (the average ablation rate is lower than 10−3 nm/pulse); in this case, the nanoablation rate in argon is lower than in air by a factor to 6. The experimental data count in favor of the oxidation mechanism of graphite nanoablation.