Crystal growth and evaluation of scintillation properties of Eu and alkali-metal co-doped LiSrAlF₆ single crystals for thermal neutron detector

In recent work, Na co-doping have found to improve the light output of Eu doped LiCaAlF₆ (Eu:LiCAF) for thermal neutron scintillator. We grew Eu 2% and alkali metal 1% co-doped LiSAF crystals by Micro-Pulling down method to understand the effect of alkali metal co-doping on scintillation properties and mechanism compared with LiCAF. In photo- and α-ray induced radio-luminescence spectra of the all grown crystals, the emissions from d-f transition of Eu²⁺ were observed. Without relation to excitation source, decay times of co-doped LiSAF were longer than Eu only doped one. The light yield of Na, K and Cs co-doped LiSAF under ²⁵²Cf neutron excitation were improved. Especially, K co-doped Eu:LiSAF reached 33200 ph/n, which outperformed Eu only doped one by approximately 20%.