Improvement of Scintillation Properties in Pr Doped ${\rm Lu}_{3}{\hbox {Al}}_{5}{\rm O}_{12}$ Scintillator by Ga and Y Substitutions

Pr:(Lu,Y)₃(Ga,Al)₅O₁₂ single crystals were grown by the micro-pulling down ( μ-PD) method. Luminescence and scintillation properties were measured. The substitution phenomenon in the Lu³⁺ sites with Y³⁺ and Al³⁺ sites with Ga³⁺ in garnet structure has been studied. Pr³⁺ 5d-4f emission within 300-400 nm accompanied by weak Pr³⁺ 4f-4f emission in 480-650 nm were observed in Ga 0-60 at.% substituted samples. Only Pr³⁺ 4f-4f emission was observed in Ga 80 at.% substituted sample. The light yield of Pr1%:Lu₂Y₁Ga₂Al₂O₁₂ sample was almost the same as that of Cz grown Pr:LuAG standard. Two-component scintillation decay of 17.9 ns (93%) and 68.0 ns (7%) were obtained using the PMT and digital oscilloscope TDS5032B. Slower decay components were reduced by Ga and Y substitution in LuAG structure.