Gd^(3+) content optimization for mastering high light yield and fast GdxAl_(2)Ga_(3)O_(12):Ce^(3+) scintillation ceramics

Tailoring of the composition of the scintillation ceramics Gd_(x)Ce_(0.03)Al_(2)Ga_(3)O_(12)(x=2.89-3.07) heavily doped with Ce was performed.The co-precipitation is found to be quite a useful method to provide a purpo seful deviation of Gd content from the stoichio metric ratio in powders for their further compacting and sintering in the air.The effect of the composition variations on microstructure,phase composition,luminescent and scintillation characteristics is demonstrated.It is shown that Gd content below the stoichiometric composition leads to increasing the grain size but,quenching of the photoluminescence and the scintillation,whereas excess Gd leads to higher luminosity;the maximum value is obtained for the composition with an excess of Gd ~2%.Ceramics possess a light yield of -50000 ph/MeV,effective scintillation kinetics of 50 ns,and is a good candidate for application in a new generation of scanners utilizing pulsed X-ray sources.