Copper oxide tailors multifunctional properties of fluorobarioborate glasses for optical dielectric and shielding applications

The effect of CuO on the structural, optical, dielectric, and radiation shielding properties of copper fluorobarioborate (CFBB) glasses synthesized by the melt-quench technique with a general composition xCuO–(50 − x)B2O₃–35BaO–15MgF₂ (0–0.5 mol%) was investigated. XRD measurements indicated that all the samples, except those with higher values of CuO, were amorphous in nature. FTIR studies exhibited stable BO₃, BO₄, and B–O–B units, indicating an insignificantly modified borate network. The UV–Vis spectral studies showed enhanced UV absorption with the increase in the concentration of CuO. The value of both the direct and indirect optical band gaps is found to be almost the same (3.48–3.60 eV). Dynamic measurements of dielectric properties showed strong frequency dispersion, characterized by decreased ε′ and ε′′ and conductivity behavior based on hopping mechanisms. The radiation shielding parameters show high attenuation at low photon energies and improved shielding for CFBB glasses with increased CuO content. Hence, CFBB glasses have sufficient promise for optical transparency coupled with stable dielectric behavior and effective γ-ray attenuation. The novelty of this study is in simultaneous investigations concerning optical clarity, dielectric stability, and shielding efficacy in low CuO-doped fluorobarioborates, emphasizing their potential usage in multiple ways due to their multifunctionality.