PREPARATION OF DIVALENT BETA-ALUMINA CERAMICS VIA ION-EXCHANGE FROM K-ALUMINA AND NA-BETA''-ALUMINA CERAMICS

Dense polycrystalline Pb-, Sr-, Ca- and Cd-beta- and -beta"-alumina ceramics have been prepared by ion exchange in molten salts. The starting materials K-beta"-alumina (Li- and Mg-stabilized) and Na-beta"-alumina ceramics (Li-stabilized) were synthesized from the carbonates and gamma-alumina as precursors by solid state reaction. The materials were characterized by X-ray powder diffraction, chemical analysis (ICP) and weight change measurements. The conductivities of the polycrystalline materials were measured by the impedance technique and showed considerably lower values compared to divalent beta"-alumina single crystals.