Preparation and characterizations of glasses in the TeO2–Ga2O3–M2O (M═Li, Na, K) systems

Abstract

Glasses in the TeO₂–Ga₂O₃–M₂O (M═Li, Na, or K) systems were synthesized by a melt-quenching technique. The glass forming areas were delimited for each system. Systematic analyses were performed on two series of samples—the first one with a constant TeO₂/Ga₂O₃ ratio of 85/15, that is, [(TeO₂)_0.85(Ga₂O₃)_0.15]_100−x[M₂O]_x with 0 ≤ x ≤ 25 (with a step of 5 mol%), the second one with a constant alkaline oxide concentration of 10 mol%, that is, [TeO₂]_90-y[Ga₂O₃]_y[M₂O]₁₀ with 5 ≤ y ≤ 15 (with step of 2.5 mol%). The values of the glass transition temperature, density, and optical transmission parameters (the positions of short- and long-wavelength absorption edge and the maximum transmittance value) were determined. The changes in these parameters were studied for varying glass compositions. In addition, the values of refractive index were measured at various wavelengths across the whole transparency region reaching from the visible up to the mid-infrared range.