Abstract
The thermodynamic properties of the spinel Mg 2SnO 4 have been determined by emf measurements on the solid oxide galvanic cell, Pt,W,MgO+ Mg 2 SnO 4+ Sn Y 2 O 3 − ThO 2 Sn + SnO 2, W,Pt in the temperature range 600 to 1000°C. The Gibbs' free energy of formation of Mg 2SnO 4 from the component oxides can be expressed as 2 MgO (r.s)+ SnO 2 ( rut)→ Mg 2 SnO 4 ( sp) , ΔG°=1420−2.96T (±100) cal mole −1 These values are in good agreement with the information obtained by Jackson et al. [ Earth Planet. Sci. Lett. 24, 203 (1974)] on the high pressure decomposition of magnesium stannate into component oxides at different temperatures. The thermodynamic data suggest that the spinel phase is entropy stabilized, and would be unstable below 207 (±25)°C at atmospheric pressure. Based on the information obtained in this study and trends in the stability of aluminate and chromite spinels, it can be deduced that the stannates of nickel and copper(II) are unstable.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.