Luminescence properties and scintillation response in Ce3+-doped Y2Gd1Al5-xGaxO12(x = 2, 3, 4) single crystals.

The compositional dependence of luminescence properties and scintillation response were investigated in Ce³⁺-doped Y₂Gd₁Al_5-xGaxO₁₂ (x=2, 3, 4) single crystals. The Gd³⁺ → Ce³⁺ energy transfer was evidenced by photoluminescence excitation spectra of Ce³⁺ emission. With increasing Ga content in the garnet host, the Ce³⁺ luminescence from the lowest 5d level (5d1) is shifted toward higher energy due to the decrease in the crystal field splitting of the 5d levels. Light yield (LY) and its dependence on the amplifier shaping time were measured under excitation with γ-rays High LY value of ~38 000 ph/MeV was obtained for a Y₂Gd₁Al_5-xGaxO₁₂:Ce sample. Scintillation decay was measured with an extended dynamical and temporal scale under the nanosecond pulse soft X-ray excitation. The decrease of both LY value and relative contribution of slower decay component in the scintillation response was observed with increasing Ga content in the garnet host. [ABSTRACT FROM AUTHOR]