X-RAY-DIFFRACTION STUDIES OF SELF-ION IRRADIATED SYNTHETIC SINGLE-CRYSTAL DIAMOND

Synthetic single crystal diamonds were irradiated with 100 MeV carbon ions up to a fluence of 3.6 x 10(15) ions/cm2 at about 100 K and with 3 MeV electrons up to 1 x 10(19) e/cm2 at 60-degrees-C. Volume changes after irradiation were studied by means of lattice parameter measurements by X-ray diffraction, indicating linear increases of the lattice parameter with fluence. A drastic increase of the integrated intensity of the scattered X-ray was observed after ion irradiation, and a large increase after electron irradiation. The drastic change is due to the so-called ''disappearance of the extinction effects'' in the dynamical diffraction theory, which is associated with the introduction of defects by the irradiation. The integrated scattering intensity in diamond is very sensitive to the amount of defects produced by the irradiation.