Solid state-reaction between Ir and Al₂O₃

The solid state reaction between Ir and Al₂O₃ powders in a vacuum was investigated and the reaction thermodynamics were calculated under non-standard conditions. It was found that the Ir and Al₂O ₃ powders were treated at temperatures of 1540° C and 1800°C in vacuum for 10 hour. It was observed that the pressure of oxygen was very low and the activity of oxygen was much lower than unity because of the vacuum atmosphere. The results show that the reaction between Ir and Al ₂O₃ can proceed easily at low temperatures in the presence of a reductive atmosphere such as carbon and the same conclusion can be drawn for Ir-Al₂O₃-H₂.