High-fluence ion-beam modification of a diamond surface at high temperature

The results of experimental investigation into modification of the (111) face of a synthetic diamond crystal under high-fluence 30-keV Ar+ irradiation are presented. It is found that irradiation at a temperature of 400°C leads to the formation of a conductive surface layer, which is detected in the Raman spectra as a broad band with a maximum close to the position characteristic of the G peak of graphite at 1580 cm−1. In addition, the intensity of the narrow peak of diamond at 1332 cm−1 decreases by an order of magnitude. Ion irradiation is accompanied by the suppression of the initial photoluminescence and gives rise to weak photoluminescence with a spectrum characteristic of gem diamonds.