KTb3−xGdxF10 Nano‐Glass Composite Scintillator with Excellent Thermal Stability and Record X‐Ray Imaging Resolution

Abstract Scintillators exhibiting both excellent spatial resolution and thermal stability are highly sought after. Herein, by employing a suite of techniques—including phase‐separation‐assisted crystallization, energy transfer, and compensation—Tb 3+ ‐doped nano‐glass composite (nano‐GC) scintillators are developed with good scintillation performance. The Tb 3+ ‐doped nano‐GC scintillator exhibits an unprecedented enhancement in the integrated intensity of X‐ray excited luminescence (XEL) by more than five times, as compared with Bi 4 Ge 3 O 12 (BGO) crystal. It achieves an estimated light yield of 54 900 photons MeV −1 and a sensitivity of 635.31 nGy air s −1 . An X‐ray imaging system based on the Tb 3+ ‐doped nano‐GC scintillator delivers a record resolution of 28.7 lp mm −1 at room temperature and 28.1 lp mm −1 even at 500 °C, thanks to the excellent thermal stability, namely, the scintillator preserves the original XEL intensity up to 300 °C, and ≈73% at 500 °C. The heat resistance excels currently available high‐temperature scintillation materials. These attributes, combined with robust moisture resistance, position the developed nano‐GC scintillator an exceptionally promising candidate for high‐temperature X‐ray imaging used in harsh environments.