Influence of P₂O₅ concentration on structural, thermal and optical behavior of Pr-activated fluoroindate glass

Results of X-ray diffraction, infrared spectroscopy, differential scanning calorimetry and optical emission together with lifetime measurements of phosphate fluoroindate glasses activated by Pr³⁺ ions are reported. Structural, thermal and optical behavior of multicomponent oxyfluoride glasses has been analyzed as a function of P₂O₅ concentration. Short glass-forming region exists for InF₃-based system with P₂O₅ additives. For low (4-12%) P₂O₅ concentration, thermally stable and transparent non-crystalline oxyfluoride samples based on InF₃ with relatively high ΔT factors were prepared, which can be promising for fiber drawing. For higher (16%) P₂O₅ concentrations, several diffraction lines due to the InOF polycrystalline phase were identified. Absorption edge and luminescence bands for Pr³⁺ ions in fluoroindate glasses are shifted in the direction of the lower frequency region with increasing of P₂O₅ content. Luminescence from both ³P₀ and ¹D₂ excited states of Pr³⁺ ions was registered. The ¹D₂ luminescence lifetime close to about 35 μs is independent on P₂O₅ concentration.