Abstract
The glass forming regions in the mixed-alkali borate systems with high-alkali contents were determined. The densities of the resultant glasses at room temperature were measured by the buoyancy method, from which the apparent molar volumes were calculated. The relationships between these properties and compositions of glasses were investigated.
The main results obtained were:
(1) The effectiveness of alkali ions for the glass formation in the single- and mixed-alkali borate systems is in the order of Li>Na>K.
(2) The apparent molar volume-composition curve is nearly linear for the Li-K glasses. On the other hand, the curve has a negative deviation from linearity for the Li-Na glasses and a positive one for the Na-K glasses. The experimental results were discussed in terms of the theory of field strength.
