Observation of multiple O–D vibration peaks in Li2O using FT-IR

In order to estimate the stabilities of various O–D states formed in Li2O by 3 keV D2+ irradiation, heating experiments up to 453 K were conducted. The chemical states of O–D bonds were analyzed by FT-IR, and the variation of the intensities of the O–D bonds in various chemical states were studied individually. During the irradiation, two O–D states were mainly formed in the bulk: O–D bond existing as LiOD phase or that without forming the LiOD phase. As sample temperature increased, transition of the latter to the former was observed. The apparent activation energy for the decrease of the O–D bond without forming the LiOD phase was estimated to be 60 kJ/mol over the temperature range 320–362 K, and that existing as the LiOD phase was estimated to be 130 kJ/mol over 403–453 K.