Raman Scattering in a Diamond Crystal Implanted by High-Energy Nickel Ions

Abstract

We have used Raman scattering to study the radiation damage profile in a diamond crystalline matrix and the change in its microstructure as a result of ion implantation at a subthreshold damage level. The measurements were made along the surface of a beveled thin section on natural diamond implanted by 335 MeV nickel ions with fluence ≈ 5⋅1014 cm–2. As a result of radiation damage, the diamond peak (1332 cm–1) in the Raman spectra was reduced in intensity, broadened, and shifted toward lower frequencies. In the range 1350–1820 cm–1, for the first time we identified about 20 narrow bands (width 5–13 cm–1) due to local vibrations of intrinsic defects in the disordered diamond matrix. We observed that over a broad range of radiation damage (along the thin section), the peak intensity of the 1490 cm–1 band is proportional to the intensity of the diamond peak, while the intensity of the 1630 cm–1 band is proportional to the intensity of the 100–1375 cm–1 band due to implantation-induced disordering of the diamond.