Properties of barium gallium germanate glasses

The glass-forming region density, index of refraction, glass transition temperature, T g, chemical durability and viscosity of BaO-Ga 2O 3-GeO 2 (BGG) glasses have been determined. In general, the physical properties of these ternary germanate glasses behave in a similar manner to comparable silicate glasses. Three series of BGG glasses containing a constant Ga 2O 3 content were formulated to approximate the physical property behavior of alkaline earth germanate glasses. The molar volume of the glasses in these series passes through a minimum with increasing BaO content, indicating a maximum in packing density and therefore the possibility of the existence of six-coordinated germanium ions.