Spectral studies on Cu2+ ions in sodium–lead borophosphate glasses

Abstract

Electron Paramagnetic Resonance (EPR) and optical absorption spectra of Cu 2+ ions in sodium–lead borophosphate glasses doped with different concentrations of Cu 2+ ions have been studied. EPR spectra of all the glass samples exhibit resonance signals characteristic of Cu 2+ ions. The values of spin-Hamiltonian parameters indicate that the Cu 2+ ions in sodium–lead borophosphate glasses are present in octahedral sites with tetragonal distortion. The optical absorption spectra of all the glass samples show a single broad band, which has been assigned to the 2 B 1g → 2 B 2g transition of Cu 2+ ions. The optical band gap energy ( E opt ) and Urbach energy (Δ E ) are calculated from their ultraviolet absorption edges. The emission bands observed in the ultraviolet and blue region are attributed to 3d 9 4s→3d 10 triplet transition in Cu + ion. The FT-IR spectra show that the glass system contains BO 3 , BO 4 and PO 4 structural units.