MIXED-ALKALI EFFECT IN FLUORIDE GLASSES

The effects of mixing of two dissimilar alkalis on various properties of heavy-metal fluoride glasses are reviewed. Remarkable effects are found in the electrical conductivity and dielectric loss, and minor but significant effects are found in Vickers hardness, elastic constants and dielectric constant. No appreciable effect is found in density, refractive index, thermal expansion coefficient, glass transition temperature and chemical durability.