Work

Atmosphere‐Controlled Valence Engineering of Eu in Aluminate Crystals Enabling High‐Performance Temperature Sensing and Flexible X‐Ray Imaging

Year: 2026

Type: article

Abstract: ABSTRACT Developing scintillators that simultaneously deliver high light yield, radiation stability, flexibility, and environmental sustainability remains a long‐standing challenge, while optical thermometry is further limited by narrow working ranges and insufficient sensitivity. Here, we propose a buried‐carbon reduction concept that enables precise regulation of Eu valence states through controlled carbon burial depth from a single precursor, thereby unlocking multifunctionality within one material system. By such strategy, fully reduced SrMgAl 10 O 17 :Eu 2+ is utilized in x‐ray detection and imaging. High‐energy irradiation activates defect‐mediated electron release, substantially increasing the effective concentration of luminescent centers. Remarkably, its radioluminescence intensity retains 117.5% after over 150 on‐off irradiation cycles, showing a long‐term working light yield of up to 55917 ± 573 photons MeV −1 , together with excellent linear dose response and a low detection limit. Flexible scintillator films achieve a spatial resolution of 11.7 lp mm −1 (at 20% MTF). These characteristic makes the material with low cost, flexibility, environmental protection, chemically stable, and excellent radiation resistance. Moreover, partially reduced SrMgAl 10 O 17 :Eu 2+ /Eu 3+ exhibits rare multimodal synergistic optical thermometry performance in the high‐temperature region owing to distinct thermal quenching behaviors. In the temperature range of 550–625 K, the FIR‐based S a and S r reach 0.226 K −1 and 0.97 %K −1 , respectively; the FWHM‐based thermometric mode achieves a maximum sensitivity of 0.238 nm/K, while also enabling visual discrimination of the temperature. This work establishes a versatile concept for designing advanced optical materials for radiation detection and temperature sensing.

Source: Advanced Materials

DOI: 10.1002/adma.75153