Damage and deuterium trapping in highly-oriented pyrolytic graphite

Abstract

In this work the buildup of damage due to deuterium implantation in highly‐oriented pyrolytic graphite (HOPG) is investigated. HOPG was implanted with 10–30 keV D₃⁺ at different target temperatures between room temperature and 773 K with fluences from 10¹⁴ to 10¹⁸ D/cm². Subsequently, the damage due to the implantation and the retained deuterium were measured by Rutherford backscattering (RBS) in a channeling direction (RBSc) and by the D(³He, p)α nuclear reaction analysis (NRA), respectively. The damage of selected samples was additionally observed with transmission electron microscopy (TEM). The initial trapping efficiency is unity in the whole temperature and energy range. The maximum retention of the deuterium, however, depends on the temperature and implantation energy. The damage in HOPG measured with RBSc starts to saturate at 5×10¹⁵ D/cm² (295 K) and 1.3×10¹⁷ D/cm² (773 K). Both fluences are well below the fluence at which amorphization is observed in TEM.