Composition dependence of transparency, optical, ligand field and radiation shielding properties in CdO–Fe2O3–Na2O–B2O3 glasses

Abstract

Glasses are promising and efficient radiation shielding materials. However, they still suffer from low transparency with different types of additions, which need improvements for better transparency, consistency, and service life. This paper shows the significant improvements in radiation shielding and optical properties of cadmium oxide (CdO) and iron oxide (Fe2O3) sodium borate glass system upon changing CdO/B2O3 ratios. Optical absorbance and transmittance were measured, while the band gap values were obtained from investigating the fundamental absorption edges using Tauc's plot. Our analyses show that all glass samples show good transparency in the visible range; but the transparency slightly decreases with increasing CdO/B2O3 contents. Moreover, with increasing CdO/B2O3 contents, the BO4 units increase, the density increases, and the BO3 units decrease. Furthermore, with increasing CdO/B2O3 contents, the fundamental absorption edges shift toward higher wavelengths, and the optical band gaps decrease. Also, with increasing CdO/B2O3 contents, the linear and nonlinear refractive indices increase. These behaviors were justified by electronegativity decreases and electronic polarizability increases. On the other hand, the radiation shielding properties, like the mass attenuation coefficient and half-value layer, show enhanced behaviors with further CdO additions. The combination of enhanced radiation shielding properties and enhanced transparency makes the present glasses good candidates in the radiation shielding field.