Luminescence and scintillation properties of Gd3Sc2(Al3-xGax)O12:Ce (x=1, 2, 3) garnet crystals

The luminescence and scintillation characteristics of Ce3+ - doped Gd3Sc2(Al3-xGax)O-12 (x = 1, 2, 3) garnet crystals were investigated. The Ce3+ luminescence was blue-shifted with increasing Ga content due to the decrease of the crystal field strength. A decrease of Ce3+ luminescence intensity and luminescence decay time at high temperature was observed for all samples due to thermal ionization of the Ce3+ 5d(1) excited levels. With increasing Ga content the decrease of thermal activation energies, determined from temperature dependence of decay times, was obtained. Both Gd3Sc2Al2GaO12:Ce and Gd3Sc2AlGa2O12:Ce samples exhibited a comparable light yield (LY) value of 24,000 photons/MeV while the latter sample showed faster scintillation decay time of 12 ns (11%) + 56 ns (89%) with respect to those of 55 ns (28%) + 105 ns (72%) for the former sample. An acceleration of scintillation decay time with an expense of LY value was also obtained for the Mg2+-codoped sample. At low temperature a decrease of scintillation yield was observed in correlation with the intense thermoluminescence peaks, attributing to the localization of electrons at intrinsic shallow traps.

Automated summary

The luminescence and scintillation characteristics of Ce3+-doped Gd3Sc2(Al3-xGax)O-12 garnet crystals were studied, showing a blue shift in luminescence with increasing Ga content. The decrease in luminescence intensity and decay time at high temperature was observed for all samples, attributed to thermal ionization of Ce3+ and decrease of thermal activation energies with higher Ga content. Additionally, different samples exhibited comparable light yield values but with varying scintillation decay times.