Spectroscopic studies on Pb3O4-ZnO-P2O5 glasses doped with transition metal ions

Optical absorption, Electron Paramagnetic Resonance (EPR) studies are carried out on lead zinc phosphate glass systems doped with Cr³⁺ and VO²⁺. From optical absorption investigations the crystal-field parameters Dq, B and C are evaluated. EPR measurements on Cr³⁺ systems indicate that Cr³⁺ ions are located at sites with low symmetry. EPR spectra of vanadyl doped system revealed the characteristic nature of vanadyl ion. Spin-Hamiltonian and hyperfine values are evaluated for both the systems. Optical absorption spectra of vanadyl doped system revealed three bands that are characteristic of VO(II) ion in tetragonally distorted octahedral site. By correlating both EPR and optical data, the dipolar coupling constant (P) and Fermi-constant coupling parameter (κ) and molecular orbital coefficients β^?2, e_π^?2 are evaluated. Electron Paramagnetic Resonance and optical absorption studies showed that the chemical bonds of Cr³⁺ ions and VO²⁺ ions with the ligands have more covalent nature. From these studies it is also observed that lead spinals are playing major key role in sustaining the covalent nature of bonding.