Effect of morphology on the properties of alkaline earth silicate glasses

The effect of morphology on the thermal expansion behavior, helium permeability, density, and refractive index of alkaline earth silicate glasses has been determined for the calcium, strontium, and barium silicate systems. These data have been used to determine the miscibility limits and the limits of connectivity of the high silica phase for each of these systems. The miscibility limits occur at approximately 46, 42, and 40 mol% CaO, SrO, and BaO, respectively. The limit for a connected high silica phase occurs at approximately 33, 25, and 22 mol% CaO, SrO, and BaO, respectively. This paper demonstrates the use of these techniques in the determination of the morphology of simple glass-forming systems.