Chemical sputtering of sintered diamond compacts and diamond film

The chemical sputtering of sintered diamond compacts and diamond film have been measured as a function of target temperature and incident energy of protons. The C₂ hydrocarbon production yields were 25%–55% smaller for the diamond compacts and the diamond film as well as the CH₄ production yields 12%–14% smaller for the diamond compacts than for graphite, depending on incident energy, whereas the diamond film had the similar CH₄ yields of graphite. The Raman spectroscopy shows that the bombarded surfaces of diamond compacts and film still had sp³ configuration of diamond structure even though they were irradiated up to a high fluence of more than 10²⁰ H/cm², whereas the bombarded graphite surface changed into microstructure domains. These results are considered to be the reasons why the yields are lower for the diamond compacts and film than for graphite and also why the steady yields of graphites differently fabricated have the similar values after prolonged irradiation.