BaO-Ga2O3-GeO2 glasses with enhanced properties

Varying substitutions of In2O3 for Ga2O3 in the BaO-Ga2O3-GeO2 glasses were made and their effects on the glass transition temperature, density, hardness, chemical durability and the infrared transmission were studied. In2O3 substitution for Ga2O3, in general, resulted in improvement in the physical properties of these glasses, The glass transition temperature, density and hardness increased with the substitution. The chemical durability of these glasses improved with the substitutions and the infrared (IR) cut-off edge shifted to longer wavelengths. Phase separation was observed in compositions with higher In2O3 substitutions. The observed changes in physical properties and phase separation with In2O3 substitutions are explained on the basis of a structural model suggesting that octahedrally coordinated In3+ replaces tetrahedrally coordinated Ga3+ in the glass structure. The observed results are in good agreement with the model which also explains the phase separation observed at higher In2O3 substitutions.