Rare earth-doped lead borate glasses and transparent glass–ceramics: Structure–property relationship

Correlation between structure and optical properties of rare earth ions in lead borate glasses and glass–ceramics was evidenced by X-ray-diffraction, Raman, FT-IR and luminescence spectroscopy. The rare earths were limited to Eu3+ and Er3+ ions. The observed BO3 ↔ BO4 conversion strongly depends on the relative PbO/B2O3 ratios in glass composition, giving important contribution to the luminescence intensities associated to 5D0–7F2 and 5D0–7F1 transitions of Eu3+. The near-infrared luminescence and up-conversion spectra for Er3+ ions in lead borate glasses before and after heat treatment were measured. The more intense and narrowing luminescence lines suggest partial incorporation of Er3+ ions into the orthorhombic PbF2 crystalline phase, which was identified using X-ray diffraction analysis.