Growth and luminescent properties of Ce-doped LiF/LiLuF4 eutectic fibers grown by micro-pulling-down method

The undoped and Ce-doped LiF/LiLuF4 eutectic fibers with various ratios of LuF3 to LiF were grown by the micro-pulling-down method for their application as neutron scintillators with light guiding structure. The differential thermal analysis (DTA) of undoped eutectic materials indicated that the eutectic point of LiF/LiLuF4 was positioned around LiF 80 mol%–LuF3 20 mol% composition. Some of the as-produced eutectic solids had rod-like regular array structures. This was observed using SEM images of cross-sectional and parallel cuts of the grown solids. In the range of x ≥ 0.28, the dendrites appeared between the eutectic areas. Ce doped LiF/LiLuF4 eutectic fibers demonstrated two emission peaks around 310 and 326 nm in the photoluminescence spectrum, and the decay time of the emission at 326 nm was 32.3 ns.