The scintillation mechanisms in Ce and Tb doped (GdxY1-x)Al2Ga3O12 quaternary garnet structure crystalline ceramics

Highlights: • Scintillation mechanisms of quaternary garnet type (Gd_x,Y_1-x)₃Al₂Ga₃O₁₂ ceramics doped with Ce or Tb were investigated for the first time • A role of the Frenkel type excitons in the energy transfer processes at both dopings is under discussion • The light yield of Tb doped samples was estimated to be ~200,000 ph/MeV Scintillation mechanisms and performance parameters of quaternary (Gd,Y)₃Al₂Ga₃O₁₂ compositionally disordered polycrystalline garnet type ceramics doped with Ce or Tb have been investigated for the first time. Similar light yield dependence on a Gd content in the composition was evidenced for both dopants. The highest light yield achieved in Tb doped samples was found to be four times higher than in Ce doped samples, which was achieved by tuning of the resonance conditions for energy transfer from Gd subsystem to Tb³⁺ activators due to the variation of Gd content in the matrix. The exceptional role of the Gd³⁺ subsystem is forming the high light yield of Tb doped quaternary garnets under different kinds of ionizing radiation is pointed out.