Spectral analysis of Cu2+: B2O3-ZnO-PbO glasses

A new series of heavy metal oxide (PbO) based zinc borate glasses in the chemical composition of (95 − x)B2O3-5ZnO-xPbO (x = 10, 15, 20, 25, 30, 35, 40, 45 and 50 mol%) have been prepared to verify their UV filtering performance. Both direct and indirect optical band gaps (Eopt) have been evaluated for these glasses. For a reference glass of 45B2O3-5ZnO-50PbO, refractive indices at different wavelengths are measured and found the results satisfactorily correlated with the theoretical data upon the computation of Cauchy's constants of A = 1.766029949, B = 159531.024 nm2 and C = −1.078 × 1010 nm4. Measurements concerning X-ray diffraction (XRD), FT-IR, differential scanning colorimeter (DSC) profiles have been carried out for this glass. The FT-IR profile has revealed that the glass has both BO3 and BO4 units. From DSC thermogram, glass transition temperature (Tg), crystallization temperature (Tc) and melting temperature (Tm) have been located and from them, other related parameters of the glass have also been calculated. Visible absorption spectra of 45B2O3-5ZnO-(50 − x)PbO-xCuO (x = 0. 1, 0.2, 0.5 and 1.0 mol%) have revealed two absorption bands at around 400 nm (2B1g → 2Eg) and 780 nm (2B1g → 2B2g) of Cu2+ ions, respectively. Emission bands at 422 and 512 nm are found for the 1 mol% CuO doped glass with excitations at 306 and 332 nm.