Thermodynamic Assessment of the Silver–Oxygen System

An assessment of the silver–oxygen system has been made, and a consistent set of thermodynamic parameters has been optimized. The calculated thermodynamic properties and phase relations are in good agreement with the experimental data. Ag 2 O is the only phase that is commonly found within the system. In air, it decomposes to silver and oxygen gas at 420 K. There is a eutectic between silver and Ag 2 O at a temperature of 804 K, an oxygen partial pressure ( P O2 ) of 526 bar (5.26 × 10 7 Pa), and an oxygen mole fraction in the liquid phase of 0.25. Uncertainties remain on the Ag 2 O liquidus for P O2 > 10 8 Pa. An ionic two‐sublattice model has been used to describe the liquid phase. This work is part of a study of interactions between compounds from the bismuth‐strontium‐calcium‐copper‐oxygen system and silver.