Carbon effect on retention and release of deuterium implanted in Mo

Retention and release behavior of deuterium in carbon deposited Mo single crystals were studied during and after 10 keV D⁺₂ implantation. Concentration profile of implanted D atoms and chemical composition in the near surface layer of Mo were measured by ion beam analysis techniques. The amount of retained deuterium in Mo at room temperature increased with carbon content in the surface layer of Mo. For the layer containing high concentration of carbon as 0.5 C/Mo, the saturation concentration of the implanted deuterium was found to be about 0.3 D/host atoms, and the total amount of deuterium in the surface layer reached 2 × 10²¹ D/m² which was 20 times larger than that in a clean surface of Mo. In comparison with the clean surface of Mo, thermal release of deuterium from the carbon contained Mo surface occurred mainly at lower temperature, and no significant release was observed above 450 K.