Thermodynamic Stability of Beta Alumina

The Gibbs energy of formation of beta alumina in equilibrium with alpha alumina has been measured over the temperature range 320°–800°C by two different equilibrium emf techniques. The results are well represented by the following equation Chronopotentiometric experiments were performed over the range 85°–140°C. If the observed plateaus are interpreted as representing the dissociation of in the beta alumina, results are in agreement with the above equation.