The Effect of Fluorides (BaF2, MgF2, AlF3) on Structural and Luminescent Properties of Er3+-Doped Gallo-Germanate Glass

Raman and Infrared Spectroscopy of Barium-Gallo Germanate Glasses Containing B2O3/TiO2

Modified barium gallo-germanate glass hosts are still worthy of attention in studying structure-property relationships. In this work, two different series of glass systems based on (60-x)GeO₂-xTiO₂-30BaO-10Ga₂O₃ and (60-x)GeO₂-xB₂O₃-30BaO-10Ga₂O₃ (x = 10, 30, 50 mol%) were synthesized, and their properties were studied using spectroscopic techniques. X-ray diffraction (XRD) patterns revealed that all fabricated glasses were fully amorphous material. The absorption edge shifted toward the longer wavelengths with a gradual substitution of GeO₂. The spectroscopic assignments of titanium ions were performed with excitation and emission spectra compared to the additional sample containing an extremely low content of TiO₂ (0.005 mol%). On the basis of Raman and FT-IR investigations, it was found that increasing the TiO₂ content caused a destructive effect on the GeO₄ and GeO₆ structural units. The Raman spectra of a sample containing a predominantly TiO₂ (50 mol%) proved that the band was located near 650 cm^-1, which corresponded to the stretching vibration of Ti-O in TiO₆ unit. The deconvoluted IR results showed that the germanate glass network consisted of the coexistence of two BO₃ and BO₄ structural groups. Based on the experimental investigations, we concluded that the developed materials are a promising candidate for use as novel glass host matrices for doping rare-earth and/or transition metal ions.

Examining the Spectroscopic and Thermographic Qualities of Er3+-doped Oxyfluoride Germanotellurite Glasses

Novel ternary fluoro-germano-tellurite (GTS) glasses doped with Er³⁺ ions with 0.5 mol% and 1.0 mol% were fabricated by a conventional melt and quenching method and investigated using methods of optical spectroscopy. The room-temperature absorption spectrum was recorded and analyzed to determine radiative transition rates, radiative lifetimes, and branching ratios of Er³⁺ luminescence. Decay curves of Er³⁺ luminesccence were recorded and analyzed. Temperature dependences of emission spectra and absorption spectra in the region from RT (room-temperature) up to 675 K were studied in detail. The contribution of competing radiative and nonradiative processes to the relaxation of luminescent levels of Er³⁺ was assessed. Absolute and relative sensitivity were established utilizing the comprehensive model based on thermally coupled ²H_11/2/⁴S_3/2 excited states of erbium. The high quantum efficiency of the first erbium-excited state and value of gain coefficient indicate that GTS:Er glass system can be considered as conceivable NIR (near infrared) laser material as well.