Transparent glasses and glass ceramics of SiO2–Al2O3–NaF–YF3: Eu3+ containing the YF3 nano-crystals were prepared in air atmosphere and their spectroscopic properties are presented. The blue emission peaked at 433 nm shown in the spectra indicate the existence of Eu2+.
The transformation of Eu3+→Eu2+ is related with the existence of F−, which is the key trigger for the transformation in air atmosphere.
In addition, the emission intensities of Eu3+ and Eu2+ were also related with the concentrations of Eu3+.
The emission intensities increased heavily with the increasing dopant of EuF3 in both glasses and glass ceramics.
When the doped concentration of EuF3 was higher than 0.5 mol.%, the concentration quenching effect occurred.