Role of the Dilution of the Gd Sublattice in Forming the Scintillation Properties of Quaternary (Gd,Lu)3Al2Ga3O12: Ce Ceramics

Technological factors and processes contributing to the scintillation mechanism have been considered in quaternary garnet ceramics doped with (Gd,Lu)(3)Al2Ga3O12. The super-stoichiometric additive of gadolinium in the material composition or its co-doping with a low concentration of Mg were found to be effective tools to suppress phosphorescence in the quaternary garnet, confirming that it is not an intrinsic property of the material. The Monte-Carlo simulation of electronic excitation transfer demonstrates that the hopping migration along the gadolinium sublattice plays an essential role in forming the scintillation kinetic parameters. Breaking the integrity of the gadolinium sublattice by substitution with heavier lutetium ions increases the role of self-trapped states in the excitation of Ce3+ ions, which ensures both an increase in the fraction of short similar to 20 ns and very long similar to 600 ns components in the scintillation kinetics.

Automated summary

By doping with super-stoichiometric gadolinium additive or co-doping with a low concentration of magnesium, phosphorescence in quaternary garnet can be effectively suppressed, confirming that it is not an intrinsic property of the material. Monte-Carlo simulation of electronic excitation transfer shows that hopping migration along the gadolinium sublattice plays a crucial role in forming the scintillation kinetic parameters. Substituting the integrity of the gadolinium sublattice with heavier lutetium ions increases the role of self-trapped states in the excitation of Ce3+ ions, ensuring an increase in the fraction of short (about 20 ns) and very long (about 600 ns) components in the scintillation kinetics.