Effect of annealing atmosphere on scintillation properties of GYGAG:Ce,Mg scintillator ceramics

Ce-doped (Gd2Y)(Ga3Al2)O-12:Mg (GYGAG:Ce,Mg) ceramics were annealed under different atmospheres. The effects of the annealing atmosphere on the Ce valence and scintillation characteristics of the GYGAG:Ce, Mg ceramic were studied. The sample annealed in oxygen had an effectively improved Ce4+/Ce(3+)ratio, demonstrated by the photoluminescence intensity and X-ray absorption near edge spectroscopy. The sample annealing in the oxygen atmosphere can improved the light yield as well as acceleration in the scintillation decay. The light yield and decay time of the ceramic were approximately 38,400 ph/MeV and 34 ns, respectively. The relative afterglow values was approximately 0.014%@20 ms. The good scintillation properties reveal the large potentials of this ceramic as a scintillation material for applications in positron emission tomography.