Structural, optical, and dielectric investigations of sodium-modified lead-bismuth borate glasses

The current study involves the synthesis of xNa2O & sdot;20PbO & sdot;(25-x)Bi2O3 & sdot;55B2O3 glass system (with 5 <= x <= 25 mol %) by melt quench technique to analyze the influence of Na2O on the structural, optical, and dielectric properties of glass samples. X-ray diffraction (XRD) confirmed the amorphous nature of the samples while scanning electron microscopy (SEM) verified glass formation through morphological analysis. FTIR and Raman spectra analysis suggests that B2O3 exists mainly as [BO4] and [BO3] structural units. PbO and Bi2O3 act as network-modifying [PbO4] and [BiO6] octahedral units accordingly. The indirect optical band gap increases with the gradual substitution of Bi2O3 by Na2O content. The synthesized glasses exhibit high electronic oxide ion polarizability (3.253-2.867), optical basicity (1.156-1.087), and metallization criterion values (0.329-0.370), indicating their suitability for non-linear optical devices. The dielectric study revealed non-Debye type behavior in the synthesized glasses.