Synthesis and Optical Characterizations of Yb3+: CaxSr1−xF2 Transparent Ceramics

In this study, 3 at.% Yb3+: CaxSr1−xF2 nanopowders were synthesized via the chemical co-precipitation method. Highly transparent 3 at.% Yb3+: CaxSr1−xF2 ceramics with various CaF2 concentrations were fabricated by hot-pressed sintering. The 3 at.% Yb3+: CaxSr1−xF2 nanopowders exhibited a spherical shape with slight agglomeration, and their particle size ranged from 26 nm to 36 nm. With an increase of the CaF2 concentration, the peak shape changed significantly and the width of the emission band increased inhomogeneously. The minimal fluorescence lifetime at the wavelength of 1011 nm of 3 at.% Yb3+: CaxSr1−xF2 transparent ceramics with various CaF2 concentrations was higher than 3.25 ms, which was longer than that of the 3 at.% Yb3+: CaF2 (2.6 ms) and the 3 at.% Yb3+: SrF2 (3.22 ms) reported in previous literature. The results indicate that incorporating Ca2+ ions into the SrF2 is an effective method to modulate the optical properties of transparent ceramics.