Role of Lithium on Chemical States and Retention Behavior of Tritium in Li₂TiO₃

Deuterium ion implantation experiments into Li₂TiO₃ and TiO₂ were performed with various ion fluences to elucidate the role of lithium on deuterium retention behavior in Li₂TiO₃. The experimental results showed that there were four deuterium trapping states in TiO₂; two of them were interacted near the surface and the others were deuterium trapped by E'-center and bound to oxygen with forming TiO-D bond in bulk. For Li₂TiO₃, there were five trapping states; four of them were the same as those in TiO₂ and the other was that bound to oxygen with forming LiO-D bond. The implanted deuterium was preferentially trapped by E'-center with forming hydroxide. LiOD phase was formed as increasing ion fluence. The retention of deuterium trapped by E'-center for Li₂TiO₃ was less than that for TiO₂, indicating that the migration of lithium via irradiation defects during implantation refrains the deuterium retention in Li₂TiO₃.