Existence states of deuterium irradiated into LiAlO2

The existence states of deuterium in LiAlO2 were analyzed by in situ IR absorption spectroscopy during irradiation with 3 keV D 2 + at room temperature. Multiple IR absorption peaks that were related to O–D stretching vibrations were observed, mainly at 2650 cm−1 (O–Dα), 2600 cm−1 (O–Dβ), and 2500 cm−1 (O–Dγ). The O–Dα was assigned to the surface O–D. The O–Dβ and O–Dγ were interpreted as two distinct O–D states for three candidates: O–D of substitutional D+ for Li+; O–D of substitutional D+ for Al3+; and O–D of interstitial D+. O–Dβ was the dominant O–D state for deuterium irradiated into LiAlO2, and had higher stability than O–Dγ. Heating after ion irradiation led to the desorption of D2 and an increase in the intensity of O–Dβ, which implies that some of the deuterium irradiated into LiAlO2 exists in non-O–D states, such as D− captured by F centers.