Crystal Growth and Scintillation Properties of Ho-Doped Lu$_{3}$Al$_{5}$O $_{12}$ Single Crystals

The crystals of 0.1, 0.5, 1, and 3% Ho doped Lu
₃
Al
₅
O
₁₂
(Ho:LuAG) grown by the micro-pulling-down method were examined for their scintillation properties. At wavelengths longer than 300 nm, Ho:LuAG crystals demonstrated around 60% transparency with many absorption peaks attributed to Ho
³⁺
4f
¹⁰
-4 f
¹⁰
transitions. When excited by
²⁴¹
Am α-ray to obtain radio luminescence spectra, broad host emission and four sharp Ho
³⁺
4f
¹⁰
-4 f
¹⁰
emission peaks were detected in the visible region. Light yields and decay time profiles of the samples irradiated by
¹³⁷
Cs γ-ray were measured using photomultiplier tubes R7600 (Hamamatsu). Ho 0.5%:LuAG showed the highest light yield of 3100 ±310 photons/MeV among the present samples. The decay time profiles were well reproduced by two components exponential approximation consisting of 0.5-1 μs and 3-6 μs.