Infrared absorption and Raman scattering from H2O in Na1−xLix beta aluminas
Abstract Infrared and Raman spectra of Na 1− x Li x beta-alumina single crystals (0⩽×⩽0.9) show bands in the 3000 to 3600 cm −1 region due to vibrations of H 2 O molecules located in the conducting plane. Hydration of Naβ-Al 2 O 3 occurs on exposure to water vapor while hydration of Na 1− x Li x β-Al 2 O 3 occurs primarily during ion exchange. The extent of hydration and stability of these hydrates increases with increasing Li + concentration. Based on a simple model, the completely hydrated state of pure lithium beta-alumina is represented by Li 2.3 O·11Al 2 ) 3 ·5.4H 2 O.