Effect of Pr3+ doping concentration on microstructure and optical properties of transparent BaF2 ceramics

As one of the quickest inorganic scintillators, BaF 2 crystal is projected to be used in medical treatment, high energy physics, geological research, and other sectors. A series of Pr:BaF 2 polycrystalline transparent ceramics with nominal Pr 3+ concentrations (0.1–5 at%) were synthesized via HP sintering in this research. XRD , FE-SEM, and TEM measurements were used to analyze the phase composition and microstructure of BaF 2 precursor powders with varying Pr-doping levels, and the results demonstrated that as concentration increases, the size of the nanopowders decreases. Furthermore, the morphology shifted from uniform square to uneven sheet. Cross-sectional SEM pictures of all samples revealed a clean grain boundary with no remaining pores or contaminants. The absorption spectra , emission spectra, and fluorescence lifetime of a group of Pr:BaF 2 transparent ceramics with excellent optical transmittance were measured and discussed after hot-pressing the precursor powders synthesized via co-precipitation method at 900 °C under an axial pressure of 50 MPa for 4 h.