REAL-TIME RAMAN MEASUREMENTS OF GRAPHITE UNDER AR+ IRRADIATION

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 X 10(11) 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 (approximately 1360 cm-1) with respect to the Raman active E2g2 mode peak (approximately 1580 cm-1). An initial steep rise and a successive slow increase to saturation of the relative intensity ratio are observed.