Structural Analysis of Sepiolite by Selected Area Electron Diffraction—Relations with Physico-Chemical Properties

M. Rautureau
1976 Clays and clay minerals  
Abstrac~The electron structural analysis of a Madagascar sepiolite (Ampandrandava) was carried out by selected area electron diffraction obtained from monocristals. Fourier projections, derived from the experimental intensity of Okl, hOl and hkO reflections, show that the Mg 2+ cations on the edges of the sheets are distributed between two sites. Correlatively the water molecules bound to these Mg 2+ occupy two distinct positions. These principal structural differences with the Brauner and
more » ... he Brauner and Preisinger model explain details of the i.r. spectra during the desorption of water or the adsorption of polar molecules. The differences between the two models can be considered as a consequence of treating the mineral in vacuum.
doi:10.1346/ccmn.1976.0240105 fatcat:ucjslxgkm5fppg4ym5hm3n2fmu