Role of Eu 2+ and Dy 3+ Concentration in the Persistent Luminescence of Sr 2 MgSi 2 O 7 Glass-Ceramics.

In this study, glass-ceramics based on Sr 2 MgSi 2 O 7 phosphor co-doped with Eu/Dy were obtained from the sintering and crystallisation of glass powders. The glasses were melted in a gas furnace to simulate an industrial process, and the dopant concentration was varied to optimise the luminescence persistence times. The doped parent glasses showed red emission under UV light excitation due to the doping of Eu 3+ ions, while the corresponding glass-ceramics showed persistent blue emission corresponding to the presence of Eu 2+ in the crystalline environment. The dopant concentration had a strong impact on the sintering/crystallisation kinetics affecting the final glass-ceramic microstructure. The microstructures and morphology of the crystals responsible for the blue emission were observed by scanning electron microscopy-cathodoluminescence. The composition of the crystallised phases and the distribution of rare-earth (RE) ions in the crystals and in the residual glassy phase were determined by X-ray diffraction and energy dispersive X-ray analysis. The emission and persistence of phosphorescence were studied by photoluminescence.