Fig. 5

a UV-visible absorption spectra, b Tauc’s Plots and c indirect energy band gap and refractive index as a function of Al2O3 concentration of all the fabricated glasses SrKS0A, SrKS2A, SrKS4A, and SrKS6A in the SrKSA glassy system respectively.

a UV-visible absorption spectra, b Tauc’s Plots and c indirect energy band gap and refractive index as a function of Al2O3 concentration of all the fabricated glasses SrKS0A, SrKS2A, SrKS4A, and SrKS6A in the SrKSA glassy system respectively.