Ionic conductivity and solid phase transitions in Na2SO4–Cs2SO4 system
- 1 December 1988
- journal article
- Published by Canadian Science Publishing in Canadian Journal of Chemistry
- Vol. 66 (12) , 3132-3136
- https://doi.org/10.1139/v88-483
Abstract
The ac conductivity and DSC calorimetry data reveal interesting solid state interactions and solid phase transition behavior in the Na2SO4–Cs2SO4 binary system. The β → α solid transition of NaCsSO4 is reported for the first time. These data indicate preferential reaction between Cs2SO4 and the high temperature phase I of Na2SO4, exemplifying the Hedvall effect, to form the compound NaCsSO4 which further interacts with excess Na2SO4 or excess Cs2SO4 to form 1:1 association complexes, viz. NaCsSO4:Na2SO4 and NaCsSO4:Cs2SO4. These complexes appear to dissociate at low temperatures reminiscent of spinodal-type decomposition behavior. The reaction enthalpies of NaCsSO4, β → α transition of NaCsSO4 and complex associations are reported.The report contains two unexpected results: (i) a subdued higher ionic conductivity relative to its Rb2SO4 analogue and (ii) a conductivity drop accompanying the high temperature phase transition which is in strong contrast to all the other Na2SO4 – mixed alkali compositions.Keywords
This publication has 0 references indexed in Scilit: