Resistivity‐Microstructure Relations in Lithia‐Stabilized Polycrystalline β”‐Alumina

The sodium ion resistivity of lithia-stabilized polycrystalline β”-alumina was measured as a function of temperature for fine-grained and coarse-grained specimens with a chemical composition of 8.80 Na20-0.75 Li2O-90.45 A12O3 (wt%). A model is presented which explains the dependence of sodium ion resistivity on grain size. Using the model the activation energy was determined for the transport of sodium ions across a grain boundary in this form of sodium β”-alumina.