EFFECT OF B₂O₃ ON PHYSICAL AND OPTICAL PROPERTIES OF ZINC PHOSPHATE GLASSES

Abstract

Zinc-phosphate glasses with the addition of B 2 O 3 were prepared by using the melt quench technique. These glasses had a mol% composition of 30ZnO − xB 2 O 3 -(70 − x)P 2 O 5 . The quantity x had values of 10-40 mol%. The mass density of these glasses was found to be in the range of 2.4912-3.0142 g/cm 3 . The oxygen packing density and molar volume were estimated to lie in the range 192.385-286.026 g-atom/liter and 46.78-31.46 cm 3 respectively. The absorption spectra of these glasses were recorded in the range of 190 to 1100 nm. No sharp edges were found in the optical spectra, which confirms the amorphous nature of these glasses. The optical band gap energies were determined to be in the range of 2.40-3.00 eV. A decreasing behavior in optical band gap energy was seen due to the increasing concentration of B 2 O 3 . The extent of band tailing was worked out from the Urbach plots, which showed an exponential dependence of absorption coefficients on photon energies.