Critical Evaluation of the Literature Data on Beta Alumina and Related Phases: I, Phase Equilibria and Characterization of Beta Alumina Phases

From a critical evaluation of the available data on the system Na 2 O‐Al 2 O 2 and particularly on β‐Al 2 O 3 some of the discrepancies in the literature were resolved, and plausible phase diagrams for the system were constructed. The diagrams define needed equilibrium data and are useful in putting into perspective the problems that have arisen with regard to synthesis and characterization of the 3–block and 3–block forms of β‐Al 2 O 3 .