Structural, optical, and radiation shielding properties of germanium bismuth borate glass modified with erbium oxide

Abstract

This study explores the structural, optical, and gamma-ray shielding characteristics of Er2O3-doped germanium bismuth borate glasses with the composition xEr2O3-(60-x)B2O3-35Bi₂O₃-5GeO₂ (x = 0–0.6 mol%). Prepared using the melt-quenching technique, the glasses were characterized through FTIR spectroscopy, UV-Vis-NIR analysis, and gamma-ray attenuation tests. FTIR spectra confirmed the presence of a borate network (BO3/BO4 units), while UV-Vis-NIR spectroscopy detected Er³⁺ transitions, confirming successful doping. The addition of low Er₂O₃ concentrations (< 1 mol%) enhanced optical performance without disrupting structural integrity. The glasses demonstrated high density (4.803–4.843 g/cm³) and excellent gamma-ray attenuation, surpassing traditional shielding materials like concrete. WinXCom simulations and NaI(Tl) detector measurements indicated that this enhanced shielding arises from the high atomic number (Z) of bismuth (Bi) and erbium (Er). Notably, the 0.4 mol% Er2O3-doped sample exhibited the lowest half-value layer (HVL), tenth-value layer (TVL), and mean free path (MFP), highlighting its superior shielding efficiency. Judd-Ofelt theory analysis revealed improved luminescence efficiency, further supporting the material’s potential for optoelectronic applications. These Er2O3-doped glasses exhibit a promising combination of tailored optical properties and strong radiation attenuation, making them suitable for advanced photonic devices and radiation shielding in nuclear and medical fields.