Effect of Phosphorus-Containing Dispersant on the Microstructure and Optical Properties of Scintillation Ceramic (Gd, Y)3(Al, Ga)5O12:Ce with Garnet Structure

Phosphoric acid ester, a typical component of commercial dispersants, affects the functional properties of Gd1.494Y1.494Ce0.012Al2Ga3O12 ceramics. In sintered ceramics, the residual phosphorus can reach up to 40–70% of the introduced amount. The admixture of phosphorus located on the surfaces of the particles activates the grain growth during sintering and leads to the formation of secondary phases of rare-earth phosphates. With increasing phosphorus concentration, the density and optical transmittance of ceramics decrease. Relatively small amount of phosphorus can improve the luminescence properties of ceramics, but large amounts can increase phosphorescence and reduce the scintillation light yield.