Investigations on order and disorder in a range of sodalites

Abstract

This work is centered around analysis of the local atomic structure in synthetic sodalites through spectroscopic and X-ray scattering based analysis. A special focus lies on the application of pair distribution function analysis (PDF) and the determination of PDF data quality from laboratory instruments. The investigated samples were synthesized via hydrothermal synthesis for sodalites with ClO3- as template and AlSiO, GaSiO and AlGeO framework types. Sol gel synthesis was used to synthesize sodalites with H2O as template and ZnPO framework type. ClO3- was incorporated into sodalites with AlSiO, GaSiO and AlGeO framework types. Using PDF Rietveld, the effect of symmetry breaking at the template position on the local structure was described through two Na+ positions, that depend on the orientation of ClO3-. Interactions of ZnPO sodalites with incoporated H2O were analyzed at low temperature. Below 180 K, the disorder of extra-framework Na+ switches from dynamic to static disorder, as could be shown through temperature dependent Raman spectroscopy and PDF based structure optimization of largebox structure models