Unlocking Time‐Extended Radiation Dosimetry via Construction of Thermally Stable SrB ₄ O ₇ :Sm ³⁺ Photochromic Glass

ABSTRACT The utilization of X‐ray technology has fundamentally revolutionized the field of medical imaging, radiation therapy, and industrial nondestructive testing. However, ionizing radiation poses significant health risks upon overdose exposure, which necessitates advancement of robust, accurate, and user‐friendly radiation dose assessment systems as a critical safeguard. In this study, Sm 3 ⁺‐doped SrB 4 O 7 photochromic glasses are prepared via a facile microwave‐assisted solid‐state (MASS) method (within 10 min), which exhibit a distinctive X‐ray‐induced chromatic transition from transparency to pronounced darkening, demonstrating high‐contrast photochromic response ( ΔR c = 45.7%) and high sensitivity (1.53 mGy). Significantly, the photochromic response is exclusively induced by X‐ray exposure, rather than by ultraviolet radiation or visible light. This specificity affords a high precision in radiation dosimetry. Furthermore, it exhibits robust photochromic thermal stability (up to 200°C) and exceptional reversible cyclability (bleaching efficiency of 99%) for time‐extended X‐ray detection, attributed to the broad distribution of deep traps (0.97–1.62 eV). This study not only develops a rare‐earth‐doped glass system for a distinctive precision in radiation dosimetry, but also elucidates the mechanistic principles underlying X‐ray‐activated photochromism, paving the way for advanced applications in both real‐time and time‐extended radiometric monitoring and environmental protection technologies.