Structural, optical, and electrical characterization of borate glasses doped with SnO2

Synthesis of borate glass matrix of composition 35Li2O-10ZnO-55B2O3 + x SnO2 wt% (x = 0.00, 0.50, 1.00, 1.50, 2.25 and 3.00) has been carried out by solid state reaction method. Nature amorphosity of these glasses was confirmed via X-ray diffraction (XRD) measurements. UV-visible absorption spectra within the 200-1100 nm wavelength range of these samples were performed. The direct/indirect optical energy gap (Egopt), Urbach energy (EU), Fermi energy (EF) were calculated. Both the optical complex dielectric constant (ε), and the optical conductivity (σopt) for the prepared glass samples were calculated by using the measured refractive index (n) and extinction coefficient (k). All the optical properties vary depending on the SnO2 content in borate glass samples. Refractive index (n) and the optical conductivity (σopt) increase with increasing SnO2 concentration. Dielectric measurements depict that both the dielectric constant (ε′) and dielectric loss (ε″) decrease with the increasing of frequency but a constant value was obtained beyond 10 kHz up to 100 kHz. However, ac conductivity (σac) increases with the increasing in frequency.