Correlation between crystal grain sizes of transparent ceramics and scintillation light yields

Light yields of Y2O3 ceramics are different from specimen to specimen. Nature of this phenomenon is not clear yet. Furthermore, origin of emission peaks for Y2O3 is not well understood. The results reported suggest that the emission derived from trapped excitons originates from the defects accumulated in the grain boundaries of the ceramics. In this paper, average grain size is introduced in order to evaluate defects inside the ceramics. Relationship between average crystal grain size and scintillation light yield is demonstrated.