Improvement of Scintillation Properties in Pr Doped Lu3Al5O12 Scintillator by Ga and Y Substitutions

Pr : (Lu, Y)(3)(Ga, Al)(5)O-12 single crystals were grown by the micro-pulling down (mu-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.