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Structure and fluorescence properties of Dy‐doped alkaline‐earth borophosphate glasses

Dysprosium- doped borophosphate glasses, containing the divalent cations Mg 2+ , Ca 2+ , Sr 2+ , Ba 2+ , and Zn 2+ , are prepared by the melt- quenching technique. The structure of the glasses is investigated by Raman, infrared, and nuclear magnetic resonance (NMR) spectroscopies and the fluorescence properties are determined. The Dy 3+ emission lifetime increases with an increasing ionic field strength and its maximum is observed in the Mg 2+ and Zn 2+ containing glasses. This result can be explained by the stronger M- O bonding which causes a rearrangement of the borophosphate network and creates a local Dy 3+ environment of comparably low symmetry. This is in agreement with the Raman spectra and the evolution of the molar volume. The effect of the B/P variation on the emission properties of Dy 3+ is investigated in a second series of glasses where the emission lifetime is found to be maximum at 10 mol% B 2 O 3 .