Enhanced visible luminescence intensities in hot-pressed Pr, La:SrF2 transparent ceramics by co-doping with LaF3

Pr, La:SrF 2 ceramics co-doped with various amounts of LaF 3 were fabricated by hot-pressing (HP) sintering in a vacuum environment. The transmittance of the Pr, La:SrF 2 ceramics was gradually improved with the increase in sintering temperature , and the sintering temperature of 1000 °C was adequate to fabricate highly transparent ceramics without rapid grain growth. Residual pores and undissolved PrF 3 /LaF 3 fluorides were identified as light scattering defects within the ceramic sintered at 830 °C. The effect of LaF 3 on the microstructural, transmittance, and spectroscopic characteristics of ceramics was studied systematically. The luminescence intensity of the Pr, La:SrF 2 ceramics was drastically enhanced through LaF 3 co-doping, while the optical transmittance first slightly increased and then decreased. The ceramic sample co-doped with 1 wt% LaF 3 exhibits the highest transmittance with the smallest grain size of 43.4 μm, and the transmittance reaches 87.8% at 400 nm and 87.2% at 1100 nm.