Direct influence of La on structure, optical and gamma-ray shielding properties of lead borate glasses

Lanthanum lead-borate glasses with chemical formula (50B(2)O(3)-10ZnO - (40-x)PbO) + x La2O3 wt% where (x = 0, 0.25, 0.5, 1, 1.75 and 2.5) have been prepared by the conventional melting method. FTIR measurements for the produced glasses in 4000-400 cm(-1) and UV-vis spectra in 190-1100 nm wavelength have been carried out. Optical energy gap and index of refraction for the proposed glasses were evaluated using the absorbance spectrum fitting (ASF) and derivative absorbance spectrum fitting (DASF) models. In ASF method, the optical energy band gap was varied from 2.839 to 2.442 eV, while in DASF was from 2.851 to 2.777 eV for the indirect transition. The single-oscillator energy, dispersion energy parameter for all studied glasses were calculated. Indeed, molar refractivity (R-M), molar polarizability (alpha(M)), reflection loss (R-L), dielectric constant (epsilon), optical electronegativity (Delta chi*), nonlinear optical susceptibility (chi((3))), and nonlinear refraction index (n(2)) have been determined. The capability of using the glasses as a promise radiation shielding was examined by calculating the mass attenuation coefficient by using WinXCOM and Phy-X/PSD programs within the photon energy (0.015-15 MeV). Attractive related shielding parameters such as; half value layer, effective atomic number, and mean free path along the considered photon energy range have been evaluated. Results were compared with some heavy metal oxide (HMO) and commercial glasses. Results reflected that the investigated glasses can be developed to be applied for photonics devices and protecting against exposure to ionizing radiation.