Dopant concentration dependence on optical and scintillation properties of Eu-doped Gd₃Al₂Ga₃O₁₂ single crystals

We have studied scintillation properties of Eu3+-doped Gd3Al2Ga3O12 single crystals. Gd3Al2Ga3O12 single crystals with different concentrations of Eu3+ (0.5%, 1.0%, 5.0%, 10.0%, and 15.0%) were grown using the floating-zone method. In photoluminescence (PL) and scintillation properties, the Eu-doped Gd3Al2Ga3O12 single crystals showed emission peaks and several millisecond decay times due to 4f-4f transitions of Eu3+ ions. Pulse height spectra of all the samples were investigated under gamma-ray irradiation from Cs-137 (662 keV). The 0.5%, 1.0%, 5.0%, and 10.0% Eu-doped samples showed full energy peaks. Among all the samples, the 5.0% Eu-doped Gd3Al2Ga3O12 single crystal showed the highest light yield of 36 000 photons MeV-1.