STRUCTURAL DESIGN OF Eu²⁺-CONTAINING GLASS AND GLASS-CERAMICS BASED ON THE SYSTEM BaO–ZrO₂–SiO₂–MgF₂ FOR LED APPLICATION

For the first time, an approach to designing the structure of Eu²⁺ containing silicate glass-ceramics materials has been experimentally implemented, which consists in the fact that rare earth activator is introduced into various crystals formed during glass crystallization. Transparent Eu-containing glass and glass ceramics based on the system BaO–ZrO₂–SiO₂–MgF₂ were prepared by the traditional glass melting method at 1450°C. The crystal structure and properties of materials were characterized by XRD analysis and photoluminescence spectroscopy during different stages of glass crystallization. It is shown that the simultaneous incorporation of Eu into different silicate crystals (Ba₂SiO₄, BaMgSiO₄, and BaSiO₃) formed during the glass crystallization leads to the formation of a material with a wide luminescence band in the visible part of the spectrum. The study of photoluminescence and luminescence excitation spectra of the glass suggests the possibility of energy transfer from Eu²⁺ to Eu³⁺ ions. The structures of Eu²⁺ luminescent centers are similar in the glass and glass-ceramics that is related to some phase separation in the glass before crystallization. The study of luminescence properties of prepared materials showed that these materials can be promising for the application in LEDs techniques.