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Lead-free oxyfluoride borate glasses singly doped with Pr 3+ and Er 3+ were prepared and next investigated using absorption and luminescence spectroscopy. In the studied glass system, barium oxide was substituted by BaF 2 . Two luminescence bands of Pr 3+ located at visible spectral region are observed, which correspond to 3 P 0 – 3 H 4 (blue) and 1 D 2 – 3 H 4 (reddish orange) transitions, respectively. The luminescence bands due to 1 D 2 – 3 H 4 transition of Pr 3+ are shifted to shorter wavelengths, when BaO was substituted by BaF 2 . Near-infrared luminescence spectra of Er 3+ ions in lead-free borate glasses modified by BaF 2 correspond to 4 I 13/2 – 4 I 15/2 transition. Their spectral linewidths increase with increasing BaF 2 concentration. The changes in measured lifetimes of rare earth ions are well correlated with the bonding parameters calculated from the optical absorption spectra. [ABSTRACT FROM AUTHOR]

Abstract: Transparent glass-ceramics were successfully prepared during controlled heat treatment of lead borate glasses. The PbF2 particles were dispersed into a borate glass matrix which was evidenced by X-ray diffraction analysis. The phase identification revealed that crystalline peaks can be related to the orthorhombic PbF2 phase. Green up-conversion luminescence due to the 4S3/2–4I15/2 transition of Er3+ ions was registered. In comparison to the precursor glass the luminescence intensity was considerably higher, whereas the luminescence linewidth slightly decreased in the studied oxyfluoride transparent glass-ceramics. It indicated that apart of the trivalent erbium was incorporated into the PbF2 crystalline phase. [Copyright &y& Elsevier]