Local vibration around rare earth ions in alkaline earth fluorosilicate transparent glass and glass ceramics using Eu probe

By heat treating the alkaline earth fluorosilicate glass, transparent glass ceramics containing alkaline earth fluoride nanocrystallites were prepared. The luminescence spectra and phonon sideband associated with the Eu³⁺:⁵D₂ → ⁷F₀ in glass and glass ceramics were investigated to analyze the local environment around Eu³⁺. Judd-Ofelt parameters were also calculated from emission spectra, which indicated that the Eu³⁺ ions entered the precipitated CaF₂, SrF₂, and BaF₂ nanocrystallites. Heat treating could not pledge Eu³⁺ ions to coordinate with F⁻ in the precipitated MgF₂ nanocrystallites, owing to the smaller radius of Mg²⁺ than that of Eu³⁺.