Physics and Chemistry of Minerals

, Volume 10, Issue 4, pp 187–191

Structural and IR relations among brucite-like divalent metal hydroxides

  • G. W. Brindley
  • Chih-Chun Kao
Article

DOI: 10.1007/BF00311476

Cite this article as:
Brindley, G.W. & Kao, CC. Phys Chem Minerals (1984) 10: 187. doi:10.1007/BF00311476

Abstract

The a and c unit cell parameters of M(OH)2, brucite-like structures with M=Mg, Ni, Co, Fe, Mn, Cd, and Ca, are considered in relation to M-O distances taken as the sum of the ionic radii, MVI and OIV. The a parameters are related to (M-O) by flattening of the octahedral coordination groups, with a flattening angle α=97.4±0.4°. The c parameters are divided into the octahedral layer thickness, h(oct), and the interlayer spacing h(inter). The latter is related to the (O-H) distances, which decrease as (M-O) increases. Infrared v(O-H) stretching frequencies vary with (M-O) in the same manner as h(inter) varies with (M-O). The values of v(O-H) decrease as h(inter) decreases and the atomic weight of the cations increases. The results are consistent with previous data for cation-substituted talcs. It is suggested that the M2+ ions associated with the O2− ions modify the reduced mass of the O-H vibrations so that v(O-H) decreases with increasing mass of M.

Copyright information

© Springer-Verlag 1984

Authors and Affiliations

  • G. W. Brindley
    • 1
  • Chih-Chun Kao
    • 1
  1. 1.Materials Research LaboratoryThe Pennsylvania State UniversityUniversity ParkUSA