Effect of heavy ion irradiation on self-supported diamond sheets

The self-supported diamond sheets were deposited at various deposition pressure (Pd) using HFCVD technique. The sheets were characterized using X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM). XRD shows the growth of cubic diamond. This is confirmed by Raman spectroscopy showing a sharp line at 1332 cm−1 in all the sheets. The sheets deposited at low pressures show clean sharp facets. The sheets were irradiated with high energy Au and Ag ions of varying energy and dose. The energy range was 100–120 MeV and the dose varied between 1×1012 and 3×1013 ions. Raman spectra showed the reduction in the intensity of diamond line (1332 cm−1) as well as non-diamond band at 1550 cm−1 after irradiation. SEM images of irradiated sheets show a phase transformation on the surface of the crystal. A photoluminescence (PL) signal is observed after the irradiation of the sheets at 2.634 eV.© Elsevie