Growth of Tb-doped BaCl2/NaCl/KCl ternary eutectic and its luminescence properties.

• A novel ternary Tb:BaCl 2 /NaCl/KCl eutectic scintillator is reported. • Directionally solidified eutectic was grown by the VB method. • Columnar BaCl 2 fibres with a length of 300 μm were obtained at a growth rate of 0.01 mm/min. • The expected Tb3+ emission was observed only in the BaCl 2 phase. • The decay times of the eutectic were 0.49 ms (7.5%) and 6.64 ms (92.5%) In this study, Tb:BaCl 2 and NaCl/KCl ternary eutectics were grown using quartz ampoules via the vertical Bridgman–Stockbarger method. Each crystal phase had a polygonal columnar shape with a length of 300 µm along the growth direction. The Tb:BaCl 2 scintillator phase grew in the columnar phase. The BaCl 2 scintillator phase is expected to make optical waveguides of the scintillation light. The expected Tb3+ emission peak was observed at approximately 360–630 nm under X-ray irradiation. This emission is mainly attributed to the Tb3+5D 4 →7F 6, 7F 6 , 7F 5 , 7F 4 , and 7F 3 transitions and BaCl 2 host emission transition. The photoluminescence decay times of the Tb:BaCl 2 /NaCl/KCl eutectics was 0.49 ms (7.5%) and 6.64 ms (92.5%). [ABSTRACT FROM AUTHOR]