Structural and optical properties of vanadium doped akaline earth lead zinc phosphate glasses

Abstract

The structural properties of vanadium doped alkaline earth lead zinc phosphate glasses have been investigated by XRD, UV-Visible, EPR, FT-IR and Raman spectroscopy techniques. XRD analysis has confirmed that the samples are X-ray amorphous. The optical band gap energy (E_opt) is observed to decrease with the replacement of alkaline earth content, whereas reverse trend is observed in Urbach energy (ΔE) and optical basicity (_th). The spin-Hamiltonian parameter, dipolar hyperfine coupling and covalency parameters have been obtained from EPR spectra. Depolymerization of the phosphate network by the replacement of alkaline earth content in glasses which are consisting of mainly PO₃^2- and PO₄^3- units, was detected by FT-IR spectra. The structural modification due to breakage of P=O bond and the formationof P-O-P bonds in the different compositions have been studied by Raman spectra. The physical properties have been measured and observed to increase with the replacement of alkaline earth content. The replacement of BaO has improved the strength of the cross-links between the phosphate chains of the glass.