Changes in the structural and optical properties due to the incorporation of ZnO into cerium−cupric sodium borate glasses

In this work, the effect of ZnO additives on the structural and optical properties of some cerium/copper sodium borate-based glass has been estimated based on the results of the XRD, SEM/EDX, FT-IR, and UV–Vis spectra. The XRD revealed the amorphous nature of the as-prepared solids, while the FT-IR showed an increase in the number of the nonbridging oxygen atoms and the ratio BO₃/(BO₃ + BO₄). The ESR spectra declared that the increase of ZnO additives caused Cu- cations to accumulate, forming some clusters distributed throughout the glass network. The SEM/EDX imaging of the mid-point showed that the cluster size varies from 250 to 300 nm, with irregular distributions. The increase in ZnO content caused an increase in the value of Urbach’s energy and a decrease in the values of the optical energy gaps. The increase in the optical absorbance values was assigned to the increase in Cu- clusters formation. The increase in the values of the refractive indices and optical susceptibilities with the increase in the ZnO has been attributed to the polarizability effect of the Cu- clusters/accumulations.