Hydrogen isotope behavior in Li2O at low temperature by FT-IR

The hydrogen isotope behavior in Li2O at low temperature was studied by Fourier transform infrared spectroscopy (FT-IR) to clarify the fundamental behavior of hydrogen isotopes. In the IR spectra obtained under the deuterium ion irradiation at 228 K, three peaks at 2710, 2660 and 2605 cm−1, and a broad peak at a region of 2700–2500 cm−1 were observed, corresponding to the O–D stretching vibrations. The O–D bonds as the broad peak changed to the LiOD phase as the temperature increased. In comparison with the results of irradiation at room temperature, (i) the formation of LiOD phase was restrained, and (ii) the broad peak could be apparently observed only in the low temperature irradiation. Therefore, it was concluded that the chemical states of hydrogen isotopes in Li2O have a dependence on the sample temperature of the deuterium ion irradiation.