Preparation of novel transparent glass–ceramics containing fluoride crystals

Transparent glass–ceramics containing YLiF4 nano-crystals were synthesized by controlled heat-treatments of LiFYF3Al2O3SiO2 glass. The crystallite size estimated to be about 8 nm was much less than the wavelength of the visible light. The transmittance of the glass–ceramic with a thickness of 2 mm was more than 85% at 400 nm and as high as 95% in the infrared region. The fluorescence centered around 1000 nm was hardly observed from Er3+-doped precursor glass under 800 nm excitation, while the emission with the Stark spitting was clearly observed for the Er3+-doped glass–ceramic. The phonon sideband of the 7F0 → 5D2 excitation spectra of Eu3+ reveals that Eu3+ doped in precursor glass is in silicate network while Eu3+ doped in the glass–ceramic is in not only silicate framework but also fluoride framework. These results indicate that rare-earth ions such as Er3+ and Eu3+ could be successfully incorporated into YLiF4 nano-crystals in the glass–ceramics.

► Transparent glass–ceramics containing YLiF4 nano-crystals were synthesized.
► The transmittance of the glass–ceramic with a thickness of 2 mm was more than 85% at 400 nm and as high as 95% in the infrared region.
► Rare-earth ions could be successfully incorporated into YLiF4 nano-crystals.