Study on Chemical Behavior of Energetic Deuterium Implanted into Li₂TiO₃

Deuterium ion implantation and subsequent X-ray Photoelectron Spectroscopy (XPS) and Thermal Desorption Spectroscopy (TDS) experiments were performed with varying implantation temperatures to reveal chemical behavior of tritium produced in Li₂TiO₃. These experimental results showed that there were four deuterium trapping states; two of which were interacted with and without oxygen near the surface, and the other two were interacted with E'-center and with oxygen with the formation of O-D bond in the bulk. These trapping states of deuterium in the bulk were almost the same as those of tritium generated in thermal neutron-irradiated Li₂TiO₃. The total amount of deuterium retention in the bulk was almost constant until O-D bonds formed in the bulk were decomposed, indicating that tritium trapping could proceed under hot atom chemical reactions. It was concluded that E'-center could trap the implanted deuterium more frequently than oxygen with the formation of O-D bonds in the bulk. Annihilations of them due to oxygen recovery could increase the retention of D with the formation of O-D bonds, resulting in the almost constant deuterium retention ratio up to its decomposition temperature of 573 K.