Variable Energy Positron Beam Studies of Gold Exposed to Au+ and H+ Implantation

Abstract

The results of Doppler broadening of the annihilation line spectroscopy obtained using a variable energy positron beam for the pure gold samples exposed to 100 keV self-implantation and 250 keV H⁺ implantation are reported. The annihilation characteristics of parameter S as a function of positron energy were determined. Irradiation-induced defects were confirmed in all measured profiles. However, the S parameter distributions were not typical for the ion-implanted materials. No significant changes in the shape of defect profiles for non-defected and self-implanted samples were found. The implanted Au⁺ ions fill the earlier produced vacancies and decrease the overall defect concentration. In the case of 100 keV H⁺ implantation, the distribution does not cover the area with higher S values pointing out the presence of defects. This is caused by the localization of H⁺ inside the produced vacancies. The thicknesses of the damaged layers are smaller compared to those numerically predicted by the SRIM implantation ranges. The long-range effect was not observed.