OPTICAL ABSORPTION EDGE AND TRANSITION STUDIES OF BISMUTH PHOSPHATE (Bi2O3)X(P2O5)1-X GLASSES

Abstract

Glasses with composition xBi₂O₃.(1-x)P₂O₅ were prepared over the range 0.05 ≤ x ≤ 0.23 by a single step process of Bi₂O₃ and P₂O₅. The amorphous nature of the glass compositions was confirmed by x-ray powder diffraction (XRD) studies. The optical absorption was recorded at room temperature in a wavelength range of 200-800 nm using UV-Visible Spectrophotometer. The values of optical band gap (E_opt) have been evaluated and were found to depend on the glass composition. It gives a very good fit for indicating indirect transitions. Different Thermal Analysis (DTA) data were used to determine the glass transition temperatures of the glass and has been interpreted in terms on the role of alkaline oxide in the matrix.