Ionic Conductivity of Monocrystals of the Gallium Analogs of β- and/β′-Alumina

A-C and d-c conductivities of monocrystals of the gallium analogs of β-andβ′-alumina were measured over the temperature range from room temperature to 350°C, using both reversible and ion-blocking electrodes. Conductivities of the gallates are substantially higher than those of the corresponding aluminates, and Na-/β′-gallate has the highest conductivity [⋍1 (Ω-cm)-1 at 300°C] that has been reported for any alkali ion conductor. The transport number for electrons in the gallates is less than 10-6 at 300°C. © 1977, The Electrochemical Society, Inc. All rights reserved.