Infrared Absorption Spectra of LiOH Films in the 75- to 650-cm—1 Region

The infrared absorption spectrum in the 75- to 650-cm—1 region of an evaporated LiOH film is presented. In addition, the spectra from 225 to 650 cm—1 of LiOD and mixed LiOH, LiOD evaporated films are also presented. From this data it is possible to make wavenumber assignments for the 2Eu and 1A2u infrared active fundamental modes. The spectrum of the mixed LiOH, LiOD film demonstrates that coupling exists between motions of the OH— ions in the LiOH lattice. These results are in agreement with the lattice vibration model proposed for explaining the combination bands observed in the near infrared absorption spectrum.