The influence of Te on thermal properties of Er-doped (Ge30(Se1−xTex)70)94Ga6 chalcogenide glasses

We have studied the thermal properties of Er2S3 doped (Ge0.30(Se1−xTex)0.70)94Ga6 chalcogenide glasses alloyed with different amounts of Te (x = 0.005–0.4). All the samples were doped with 1 at.% of initial amount of Er3+ ions. The glass composition was chosen with respect to the possible use of this material system in optical amplifier applications operating in the 1550 nm telecommunications window. We have prepared the glass samples by means of melt-quenching techniques using two different synthesis procedures and starting materials. The actual concentrations of glass constituents have been measured by EDX/SEM and WDX/SEM microanalysis techniques. We have carried out temperature-modulated differential scanning calorimetry (TMDSC) measurements to evaluate the thermal stability of these glasses in terms of their glass transformation and crystallization behaviors. Thermal properties of these (Ge0.30(Se1−xTex)0.70)94Ga6 glasses changed substantially for Te content x ≥ 0.01 because of the inability of the original glass structure to accommodate the Te atoms with substantially larger atomic radius.