Spectral analysis of Cu 2+: B 2O 3–ZnO–PbO glasses

Abstract

A new series of heavy metal oxide (PbO) based zinc borate glasses in the chemical composition of (95 − x)B 2O 3–5ZnO– 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 ( E opt) have been evaluated for these glasses. For a reference glass of 45B 2O 3–5ZnO–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 nm 2 and C = −1.078 × 10 10 nm 4. 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 BO 3 and BO 4 units. From DSC thermogram, glass transition temperature ( T g), crystallization temperature ( T c) and melting temperature ( T m) have been located and from them, other related parameters of the glass have also been calculated. Visible absorption spectra of 45B 2O 3–5ZnO–(50 − x)PbO– xCuO ( x = 0. 1, 0.2, 0.5 and 1.0 mol%) have revealed two absorption bands at around 400 nm ( 2B 1g → 2E g) and 780 nm ( 2B 1g → 2B 2g) of Cu 2+ 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.