Growth and scintillation properties of Pr-doped Lu3Al5O12 crystals

Pr-doped Lu3Al5O12 (Pr:LuAG) single crystals were grown by the micro-pulling-down (μ-PD) method and Czochralski (Cz) method. The crystals were seeded-grown in the 〈1 1 1〉 direction. Dimensions up to 30 mm in length and 5 mm in diameter by μ-PD and up to 100 mm in length and 22 mm in diameter by Cz method were achieved. Concentration of Pr3+ in Cz-grown Pr:LuAG was measured. Radioluminescence spectra and photoluminescence decay of Pr:LuAG were investigated and compared to Pr-doped Y3Al5O12 (Pr:YAG) single crystals. Pr:LuAG crystals show better temperature stability of radioluminescence intensity and decay time compared to Pr:YAG, and luminescence was not quenched even at room temperature (RT). Scintillation light yield of Cz-grown Pr:LuAG was measured and compared to the standard BGO sample. Light yield of Pr:LuAG was more than two times higher than BGO and the relationship between Pr3+ concentration and light yield was clarified.