Ce Concentration Dependence of Optical and Scintillation Properties for Ce Doped LiYF₄ Single Crystals

We have investigated effects of Ce concentration on optical and scintillation properties for Ce doped LiYF4[Ce:LiYF4] single crystals. Li(Y1-x,Cex)F4single crystals with more than 75 % transparency were grown by micro-pulling-down method in the range of 0 ≤ x ≤ 0.03 and the crystals with x = 0.05, 0.1 had milky parts originated from remained starting materials. Photoluminescence spectra of all Ce:LiYF4crystals indicated two emission peaks from Ce3+ion which was substituted for Y3+ion site. Light yield and decay time of α-ray irradiation for Ce:LiYF4crystals were largely affected by Ce concentration and the largest light yield was observed for the crystal with x = 0.02. In contrast, the decay time systematically became faster with an increase of Ce concentration.