ИСТИНА

The garnet scintillator crystals family Gd3Al2Ga3O12:Ce (or GAGG:Ce) attracts increased attention due to the combination of high light yield, good energy resolution, high density and chemical stability [1]. Due to the superior scintillation properties GAGG:Ce crystals are prospective for applications in a single photon emission computed tomography and environmental radiation monitoring. A drawback of the crystal scintillation kinetics is that besides the decay component typical of Ce3+ emission (τ ~ 60 ns) additional slow decay components (τ > 200 ns) are observed as well, which worsen the scintillation performance [1]. The most remarkable suppression of the slow decay components of scintillation was observed at co-doping of GGAG:Ce with Ca ions [2]. However, the scintillation light yield was suppressed as well, and therefore, additional studies are needed for further improvement of the scintillation performance of GAGG:Ce. The studied crystals were grown by the Czochralski method at the Fomos-Materials (Moscow, Russia). Here we present the results of the study of the influence of partial substitution of Al and Ga cations by Sc as well as co-doping by Ca or Zr on the luminescence and decay characteristics of GAGG:Ce. The introduction of scandium as a structural element into the GGAG:Ce crystal results in the modification of the band structure and luminescence characteristics of the crystal. Co-doping by Ca or Zr causes the modification of defect structure that influences the distribution of traps as well as timing properties of the luminescence of doped crystals. It is shown that the introduction of scandium into GGAG:Ce allows suppression of slow decay components comparable to that obtained by Ca co-doping.