Optical, luminescence and scintillation properties of Mg2+-codoped (Lu,Y)3Al2Ga3O12:Pr garnet crystals: The effect of Y admixture

Mg - codoped Lu3-xYxAl2Ga3O12:Pr (x = 0, 1, 2, and 3) garnet crystals were grown by micro-pulling down method and scintillation characteristics were investigated. An observed red shift of the Pr3+ 5d1 → 4f luminescence with increasing Y content can be attributed to an increase in crystal field splitting of the 5d levels. Temperature dependence of radioluminescence (RL) spectra was measured in the temperature range of 10–350 K, yielding a decrease of RL yield with increasing temperature for all samples. The LuY2Al2Ga3O12:Pr,Mg exhibits light yield of 9100 photons/MeV along with two scintillation decay components of 8.6 ns (9%) and 25 ns (91%). Afterglow and thermoluminescence characteristics are also investigated.