ION-BEAM-INDUCED COMPACTION IN GLASSY-CARBON

Cross-sectional transmission electron microscopy has been used to investigate the implanted layer in glassy carbon irradiated with 50 keV C ions to a dose of 5 X 10(16) ions/cm2. It was found that in addition to the formation of an amorphous surface layer approximately 100 nm deep, the ion-beam modified layer was compacted from the unirradiated density of 1.5 to 2.4+/-0.2 g/cm3. Ion implantation was also found to increase the refractive index of glassy carbon from 1.8+/-0.1 to 2.4+/-0.1 which is also consistent with the proposition that an increase in the density of the implanted layer has occurred. The formation of a dense, amorphous carbon surface layer could explain the observed increase in wear resistance of glassy carbon following ion implantation.