SURFACE-STRUCTURE OF O(+)-ION-IMPLANTED SILICA GLASS

The surface structure of 2 MeV O+-ion-implanted silica glass has been investigated by the X-ray diffraction method and the spectroscopic method. It is found that the refractive index and density of the surface layer increases and decreases by 1% and 2.5% with the O+-ion implantation, respectively. It is inferred that silicon ions are coordinated by four oxygen ions in the surface damaged layer of the glass. The Si-O-Si bond angle decreases and the middle range ordering reduces with O+-ion-implantation. It is deduced that the surface structure of the ion-implanted silica glass is similar to that of neutron irradiated silica glass.