Crystal Growth of Ce Doped $({\rm Lu},{\rm Y})_{3}({\rm Ga},{\rm Al})_{5} {\rm O}_{12}$ Single Crystal by the Micro-Puling-Down Method and Their Scintillation Properties

Ce:(Lu,Y)₃(Ga,Al)₅ O₁₂ single crystals were grown by the μ -PD method with RF heating system. In these crystals, Ce³⁺ 4f-5d emission is observed within 500-530 nm wavelength. Emission peak shifts to shorter wavelength and the decay accelerates with increasing Ga concentration. In the case of Ce:Lu₂ Y₁ (Ga,Al)₅ O₁₂ series,the Ce0.2% Lu₂ Y₁Ga₃Al₂ O₁₂ crystal showed the highest emission intensity. In order to determine light yield, the energy spectra were measured under 662 keV ã-ray excitation (¹³⁷ Cs source) and detection by an APD S8664-55(Hamamatsu). The light yield was calibrated from Fe⁵⁵ direct irradiation peak to APD. The light yield of Ce0.2%: Lu₂ Y₁ Ga₃ Al₂ O₁₂ sample was of about 30,000 photon/MeV. Dominant scintillation decay time was of about 50 ns.