Defect engineering in Mg2+ co-doped LuAG:Ce ceramics to achieve ultrahigh fast scintillation proportion

Scintillators are a class of materials that convert high-energy radiation into visible or ultraviolet light, with wide applications in fields such as high-energy physics and medical imaging. Electromagnetic calorimeters based on inorganic scintillator materials exhibit excellent energy resolution, spatial resolution, electron/photon discrimination capability, and reconstruction efficiency. In 2020, the U.S. Department of Energy (DOE) High Energy Physics Basic Research Needs highlighted the need to develop radiation-hard and fast scintillators to meet the extreme radiation environments expected in future high-energy physics experiments. As a newly emerged scintillator material, cerium-doped lutetium aluminum garnet (Lu₃Al₅O₁₂:Ce, LuAG:Ce) ceramic scintillators demonstrate high stopping power, high light yield, fast decay time, and excellent radiation resistance. These properties make them highly promising for future high-energy physics experiments under extreme radiation conditions, such as the High-Luminosity Large Hadron Collider (HL-LHC) and Future Circular Collider (FCC-hh). However, LuAG:Ce ceramics still have some drawbacks, such as slow scintillation caused by shallow trap defects. Currently, a key research focus is how to suppress this slow scintillation in LuAG:Ce ceramics.

Recently, a team of material scientists led by Jiang Li from Shanghai Institute of Ceramics, Chinese Academy of Sciences, China reported the application of defect engineering in Mg²⁺ co-doped LuAG:Ce ceramics to obtain ultrahigh fast scintillation proportion. This work not only explains the effect of Mg²⁺ co-doping in LuAG:Ce ceramics to suppress intrinsic defect related slow scintillation light, but also predicts that similar strategy can be applied in various oxide scintillators to improve scintillation performance.

The team published their work in Journal of Advanced Ceramics on August 1, 2024.

As a consequence of material optimization, LuAG:Ce,Mg ceramics with high density (6.7 g/cm³), high fast-total ratio (99.8%), and fast decay time (~56 ns) are obtained. For results of LuAG:Ce ceramics, the fast-total ratio value is only 62.3%. In the meanwhile, the fast scintillation light yield only shows a slight loss of 6% compared to LuAG:Ce ceramic. Therefore, LuAG:Ce,Mg ceramics is a promising candidate scintillator for future high energy physics experiments.

In addition to the result of material optimization, the mechanism for this improvement was also investigated. The evolution of defects by Mg²⁺ co-doping is monitored by thermoluminescence measurements, that allow a description of the microscopic processes occurring thanks to co-doping. In parallel, the reason for slight light yield loss was also discussed via density functional theory (DFT) calculations.

Meanwhile, the research team is optimistic about the application of this strategy. They believe that the strategy could readily be applied to various oxide scintillators to improve their fast scintillation proportion.

This work was supported by the National Natural Science Foundation of China (Grant No. 12175254), the Shanghai High Level Talent Plan and the Opening Fund of Key Laboratory of Rare Earths, Chinese Academy of Sciences.

About Journal of Advanced Ceramics

Journal of Advanced Ceramics (JAC) is an international academic journal that presents the state-of-the-art results of theoretical and experimental studies on the processing, structure, and properties of advanced ceramics and ceramic-based composites. JAC is Fully Open Access, monthly published by Tsinghua University Press, and exclusively available via SciOpen. JAC’s 2024 IF is 16.6, ranking in Top 1 (1/33, Q1) among all journals in “Materials Science, Ceramics” category, and its 2024 CiteScore is 25.9 (5/130) in Scopus database. ResearchGate homepage: https://www.researchgate.net/journal/Journal-of-Advanced-Ceramics-2227-8508