DIVALENT ION-BETA''-ALUMINA ELECTROLYTES FOR THE STUDY OF THERMODYNAMIC PROPERTIES OF OXIDE SYSTEMS

Exchange of sodium ions in polycrystalline sodium beta ''-alumina, per formed in molten salts, made possible a preparation of a series of div alent ion-beta ''-aluminas. In this way the solid electrolytes conduct ing zinc, cobalt, nickel, calcium, manganese and copper ions, were pre pared. Their application to the solid-state galvanic cells is presente d. The standard Gibbs free energy of Zn, Co, and Ni silicates formatio n in the temperature range 953 K to 1323 K as well as the activities a t 1173 K in the solid solutions formed in CaO-MnO, CuO-NiO and CaO-CoO systems were determined directly from e.m.f. measurements.