Terminal solid solubilities at 900-1000°C in the magnesium oxide-zinc oxide system measured using a magnesium fluoride solid-electrolyte galvanic cell

Abstract

The terminal solid solubilities of the periclase (MgO-rich) and zincite (ZnO-rich) solid solutions in the MgO-ZnO system have been determined by measuring the activity of MgO using a solid-state galvanic cell of the type 02(g), Pt/MgO, MgF₂//MgF₂//{χMgO+(1-χ)ZnO}(s, sln), MgF₂/Pt, O₂(g) in the temperature range 900-1050° C. The ZnO activity was calculated by graphical Gibbs-Duhem integration. The activity-composition plots of both components exhibit a strong positive deviation from ideality and are characterised by a miscibility gap. The terminal solid solubilities of the periclase and zincite solid solutions obtained from the activity-composition plots are found to be in reasonable agreement with those reported in the literature.