Novel Ce3+-activated gadolinium-based glass prepared in vacuum: structure and scintillation
High-density glass scintillators are promising alternatives to crystals for next-generation radiation detection due to their low cost, excellent physical and chemical stability, and processability. In this study, a series of Ce3+-activated gadolinium gallium borosilicate (GGBS x) glasses were synthesized via vacuum melt-quenching. With increasing Gd2O3 content, glass density increased from 5.86 to 6.05 g/cm3, and molar volume from 36.43 to 39.79 cm3/mol. Extended X-ray absorption fine structure (EXAFS) analysis revealed that in GGBS 1 glass, Ce3+ exclusively adopts a hexahedral [CeO6] configuration, while Gd3+ exhibits both hexahedral and octahedral coordination with a bond length of 2.35±0.1 Å and Debye-Waller factor σ2 of 0.0122±0.0015 Å2. As Gd2O3 content increased, shallow trap depth rose from 0.804 to 0.858 eV, while deep trap depth first increased from 0.948 to 1.434 eV then decreased to 1.010 eV. GGBS 1 glass exhibited high transmittance (~80%) in the visible range and a photoluminescence quantum yield of 78.4%. Under X-ray irradiation, its X-ray excited luminescence intensity reached 128.5% of that of Bi4Ge3O12 (BGO) crystal, with a spatial resolution of 29.1 lp/mm, approaching the highest reported for glass scintillators. Under γ-ray excitation, it achieved a light yield of 1058 photons/MeV and an energy resolution of 23.7% at 662 keV. These results indicate that GGBS 1 glass scintillator warrants further development for applications in X-ray imaging and γ-ray spectroscopy.