Ionic mobilities were determined, for silicate glasses which contained one or two alkaline-earth oxides, by means of dynamic mechanical thermal analysis and conduction spectroscopy. In mixed alkaline-earth glasses, the mobilities of the alkaline-earth ions were considerably lower than those in the corresponding single alkaline-earth glasses. The glass transition temperatures of the mixed alkaline-earth glasses were also lower than those expected from a linear extrapolation of the transition temperatures of the corresponding single alkaline-earth glasses. In order to quantify the degree of decoupling of the mobile ions from the glassy network, a new decoupling ratio was defined which made use of both mechanical and electrical data. It was thus shown that the effect of mixing divalent ions was qualitatively similar to the effect of mixing monovalent ions. The mixed alkaline-earth effect was less pronounced, quantitatively, than was the mixed-alkali effect.

Mixed Alkaline-Earth Effects in Ion Conducting Glasses. B.Roling, M.D.Ingram: Journal of Non-Crystalline Solids, 2000, 265[1-2], 113-9