Bulk single crystal growth and scintillation properties of Ce and Mg co-doped Y3Ga3Al2O12 for advanced X-ray imaging

In this study, the Czochralski (Cz) growth and scintillation properties of 1-inch diameter Y3Ga3Al2O12 (YAGG) single crystals co-doped with Ce and Mg were investigated. The growth atmosphere was optimized to suppress gallium oxide evaporation and iridium precipitation on the melt surface. The segregation behavior of the cations, including Ce and Mg, was systematically examined using electron probe microanalysis and inductively coupled plasma atomic emission spectrometry. The grown YAGG: Ce, Mg crystals outperformed commercial Gd3Ga3Al2O12:Ce, demonstrating a high light yield of 46,700 photons/MeV, an energy resolution of 8.5–11.4% at 662 keV, low afterglow, and a rapid decay time of ~ 50 ns. In addition, the Y K-edge lies outside the diagnostic X-ray energy range, underscoring the suitability of YAGG: Ce, Mg for photon-counting computed tomography applications. These results demonstrate the feasibility of producing large, high-performance YAGG: Ce, Mg crystals using the Cz method and establish a foundation for further improvements through the optimization of Ce and Mg concentrations and scaling of crystal size.