Real-time Raman measurements of graphite under Ar+ irradiation

Abstract
The time dependence of the Raman spectra of graphite is measured under 3‐keV Ar+‐ion irradiation by developing a real‐time Raman measurement apparatus. An ion flux of 3×1011 ions/cm2 s is used and the time resolution of the Raman measurement is about 6 s. The lattice damage of graphite is evaluated by the relative intensity of the disorder‐induced peak (∼1360 cm−1) with respect to the Raman active E2g2 mode peak (∼1580 cm−1). An initial steep rise and a successive slow increase to saturation of the relative intensity ratio are observed.