Properties of alkali–alkaline earth metaphosphate glasses

Several properties of alkali–alkaline earth metaphosphate glasses have been measured. These properties include density, transformation range viscosity and dc electrical conductivity, with emphasis on the conductivity measurements. Glasses studied include series in which Li2O or Na2O is replaced by MgO, CaO or BaO, mixed alkali glasses containing a constant concentration of BaO and a series in which ZnO replaces BaO. The conductivity decreases by orders of magnitude as an alkaline earth oxide replaces either Na2O or Li2O. Replacement of one alkaline earth by another while maintaining the identity of the alkali ion has a much smaller effect on the conductivity of these glasses. The mixed alkali effect is evident in the conductivities of the Li–Na and Na–K glasses.