Europium and Sodium Codoped LiCaAlF6 Scintillator for Neutron Detection

A recent study has revealed that a Eu-doped LiCaAlF₆ (Eu:LiCAF) crystalline scintillator showed good scintillation response under thermal neutron exposure. We discover here that Eu and Na codoped LiCAF exhibits superior scintillation properties to Eu:LiCAF. We grew Eu 2% and Na 0.5, 1, and 2% codoped LiCAF by the micropulling down method. In radioluminescence spectra, they showed intense emission peaking at 370 nm due to Eu²⁺ 5d-4f transition. In particular, the light yield of Eu 2% Na 2%-doped LiCAF reached 40000 ph/n, which was about 30% higher than that of Eu:LiCAF.