Effect of Bi2O3 on structure and properties of zinc bismuth phosphate glass

Various glasses with different compositions (50 - 2x)ZnO-xBi2O3-(50 + x)P2O5 (x = 0-20 mol%) were prepared. This study examined the effect of the structure and properties in phosphate glass system according to the change in Bi2O3 content in ZnO-Bi2O3-P2O5 glass. The structure of the glasses was analyzed by Fourier transform infrared (FT-IR) analysis. The FTIR spectra were recorded in the spectral range from 400 to 1400 cm-1. The structural investigations based on these spectra showed the rapid depolymerization of the phosphate chains with increasing Bi2O3 content along with the formation of P-O-Bi bonds. The density, glass transition temperature (Tg), molar volume and optical properties of the glasses were determined from the structural changes in the glasses. Tg, density and molar volume increased with increasing in Bi2O3 content in the glass. The optical absorption edge (λcut-off) and optical band gap (Eg) were determined from the optical transmittance spectra of the polished samples recorded at room temperature, and found to be associated with structural changes occurring in these glasses with increasing Bi2O3 content.