Transition metal (Cr3+) and rare earth (Eu3+, Dy3+) ions used as a spectroscopic probe in compositional-dependent lead borate glasses

Compositional-dependent lead borate glasses doped with transition metal and rare earth ions were studied using absorption and luminescence spectroscopy. The trivalent Cr3+, Eu3+ and Dy3+ ions were used as a spectroscopic probe in glass samples with various PbO/B2O3 ratios. Spectral analysis indicates that Cr3+ ions occupy intermediate field sites; the both sites coexist and emit from the 4T2 (low-field) and the 2E (high-field) states, respectively. The R and Y/B values due to 5D0–7F2/5D0–7F1 and 4F9/2–6H15/2/4F9/2–6H13/2 luminescence intensity ratios of Eu3+ and Dy3+ ions, respectively, increase with increasing heavy metal (PbO) content, suggesting higher asymmetry and more covalent bonding character between rare earth and oxygen ions.