Ultra-high-crystallinity transparent glass-ceramic scintillators for high-temperature X-ray imaging
High-temperature X-ray imaging demands scintillators with high crystallinity, efficient scintillation, and robust thermal stability, yet suitable materials remain scarce. Here, we report an ultra-high-crystallinity transparent glass-ceramic (GC) scintillator strategically designed via controllable heat-treatment-induced crystallization. A sequential precipitation method is employed, where cubic CaF2 nanocrystals initially form, subsequently promoting heterogeneous nucleation and growth of hexagonal BaAl2Si2O8. Intrinsic nanoscale phase separation into F-rich and O-rich domains significantly reduces atomic diffusion distances, yielding an unprecedented crystallinity of up to 97.6%. Notably, defect traps (oxygen vacancy defects, likely located within the lattice or at crystalline/amorphous interfaces) enable efficient carrier capture and thermally stimulated release, contributing to remarkable resistance to thermal quenching. Consequently, the GC scintillator maintains 90.6% of its integrated X-ray excited luminescence (XEL) intensity at 300 °C, with the integrated XEL intensity reaching 94.2% of commercial Bi4Ge3O12 (BGO) at room temperature. This enables stable high-temperature X-ray imaging with a spatial resolution of ~10.4 lp mm−1 up to 225 °C. This work provides a versatile pathway for developing high-sensitivity scintillators for extreme-environment X-ray imaging.