Structure of LiAl[sub 2](OH)[sub 7][center dot]2H[sub 2]O

Journal Article · Mon Mar 01 04:00:00 EST 1993 · Chemistry of Materials; (United States)

DOI:https://doi.org/10.1021/cm00027a011· OSTI ID:6952348

Thiel, J P; Chiang, C K; Poeppelmeier, K R ^[1]

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1. Northwestern Univ., Evanston, IL (United States)

The room-temperature reaction of lithium hydroxide with aluminum hydroxide (bayerite) in the ratio of 1:2 produces lithium dialuminate, LiAl[sub 2](OH)[sub 7][center dot]2H[sub 2]O. Rietveld refinement of x-ray and neutron powder diffraction patterns indicate that the structure is composed of [LiAl[sub 2]-(OH)[sub 6]][sup +] layers separated by water molecules and hydroxide ions. Disorder in the stacking sequence leads to indexing the diffraction pattern on a hexagonal cell (a = 5.0972(3) [angstrom], c = 7.5524(9) [angstrom] [times] 3n layers); however, the structure is better described by a C-centered monoclinic cell with the contraints the b = a[radical]3 and cos [beta] = -a/3c (a = 5.097 [angstrom], b = 8.829 [angstrom], c = 7.741 [angstrom], and [beta] = 103.0[degree]). The diffraction patterns were refined using a model of up to 54 layers ([approx]400 [angstrom]). The layer stacking vector, which defines the angle between layers, is less than expected based on the position of the diffraction peaks. The structural complexities present in lithium dialuminate have their origins in the conditions of synthesis and the layered nature of the material. 29 refs., 10 figs., 4 tabs.

• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 6952348
• Journal Information: Chemistry of Materials; (United States), Journal Name: Chemistry of Materials; (United States) Vol. 5:3; ISSN CMATEX; ISSN 0897-4756
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360602* -- Other Materials-- Structure & Phase Studies
ALKALI METAL COMPOUNDS
ALUMINIUM COMPOUNDS
ALUMINIUM HYDROXIDES
CHEMICAL PREPARATION
COHERENT SCATTERING
CRYSTAL LATTICES
CRYSTAL STRUCTURE
DIFFRACTION
HYDRATES
HYDROGEN COMPOUNDS
HYDROXIDES
LITHIUM COMPOUNDS
LITHIUM HYDROXIDES
MONOCLINIC LATTICES
NEUTRON DIFFRACTION
OXYGEN COMPOUNDS
SCATTERING
SYNTHESIS
X-RAY DIFFRACTION