Structure and spectra of H/sub 2/O in hydrated. beta. -alumina

Journal Article · Mon Nov 15 04:00:00 EST 1982 · J. Chem. Phys.; (United States)

OSTI ID:6774307

Bates, J B; Dudney, N J; Brown, G M; Wang, J C; Frech, R

The structure and spectra of hydrated Li and Na ..beta..-alumina were investigated using neutron diffraction, infrared absorption, and Raman scattering. The dimensions of the hexagonal unit cell of a hydrated Li ..beta..-alumina crystal containing 1.55 H/sub 2/O molecules per unit cell are a = 5.591 A and c = 22.715 A. The oxygen atoms of the water molecules are located in the conduction plane between the mO, and the aBR sites; the protons, located above the below the plane, form bent hydrogen bonds with the O(4) oxygen ions. The HOH bond angle of water in Li ..beta..-alumina is 114/sup 0/ and the Vertical BarO--HVertical Bar bond distance is 0.992 A. Based on polarized infrared spectra, H/sub 2/O adopts a similar structure and orientation in Na ..beta..-alumina. Spectra of absorbed H/sub 2/O, D/sub 2/O, and HDO species show that water molecules dissociate in Li ..beta..-alumina to form OH/sup -/ and H(H/sub 2/O)/sup +//sub n/ species. No evidence was found for the dissociation of water in Na ..beta..-alumina. The absorption coefficients determined for OH/sup -/ and H/sub 2/O in Li ..beta..-alumina include local field corrections. A large local field anisotropy at the protons of H/sub 2/O is responsible for the large ratio of the intensities of ..nu../sub 3/ and ..nu../sub 1/ observed for water in Li and Na ..beta..-alumina.

• Research Organization: Solid State and Chemistry Divisions, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830
• OSTI ID: 6774307
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 77:10; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
ALKALI METAL COMPOUNDS
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
BOND ANGLE
BOND LENGTHS
CHALCOGENIDES
COHERENT SCATTERING
CRYSTAL STRUCTURE
DIFFRACTION
DIMENSIONS
ELECTROLYTES
HYDRATES
HYDROGEN COMPOUNDS
INFRARED SPECTRA
LENGTH
LITHIUM COMPOUNDS
NEUTRON DIFFRACTION
OXIDES
OXYGEN COMPOUNDS
RAMAN SPECTRA
SCATTERING
SODIUM COMPOUNDS
SPECTRA
WATER