Preparation of Eu2+ and Dy3+ co-doped Sr2MgSi2O7 translucent long afterglow glass-ceramics by recrystallization-melting and their luminescence properties

Abstract

In this work, a novel recrystallization-melting method was used to prepare Eu2+ and Dy3+ co-doped Sr2MgSi2O7 translucency long afterglow glass-ceramics with complete crystal development. The synthesis mechanism is discussed by analyzing the detection results of X-ray diffraction, scanning electron microscopy, phosphorescence spectra, and afterglow attenuation curves. The effect of different firing temperatures and crystallization time on the crystalline phase content, crystal size, and luminescence properties of the Sr2MgSi2O7:Eu2+, Dy3+ glass-ceramics samples were examined. The results show that, as compared with the traditional melt crystallization method or the two-step method, the recrystallization–melting method is able to form some Sr2MgSi2O7:Eu2+, Dy3+ crystals first under a temperature that is lower than that of the glass transition. With increasing firing temperature and crystallization time, crystal growth and recrystallization reached an equilibrium state, accompanied by the generation of liquid glassy phases. It is found that the afterglow properties are proportional to the crystalline phase content and crystal size, with the latter having a more significant effect. Under the condition of firing at 1050 °C for 10 h, tetragonal Sr2MgSi2O7 crystals with a maximum size of 20 μm were successfully synthesized for the first time. These crystals exhibited high integrity and optimal afterglow performance, with a duration close to 2 h. The recrystallization-melting method suits industrial production on large scales, and the firing temperature is evidently lowered, which effectively reduces the energy consumption of the synthesis process and significantly improves the long afterglow performance.