LuBO3:Ce3+闪烁材料的化学组成、晶体结构与相变机理的同步辐射原位高通量研究

The crystal growth of LuBO3: Ce3+ single crystal with high density, high light output and short decay time is crucial for its potential wide use in nuclear medical imaging, high energy physics and etc. However, the correlation between the chemical composition, crystal structure and phase transition mechanism of LuBO3 is still unclear, limiting the single crystal growth and application. In addition, crystal structure data with high resolution and high throughput can not be obtained using conventional powder X-ray diffraction method. In this project, the combinatorial material chip technology and gradient concentration crystal growth method will be used to screen and modify the component of LuBO3: Ce3+, as well as grow single crystals. The in-situ high throughput X-ray diffraction platform co-developed by Shanghai Synchrotron Radiation Facility (SSRF) and us, together with the phase stability calculation will be used to study the correlation between crystal structure and phase transition mechanism of LuBO3: Ce3+ with chemical composition and temperature. In addition, the influence of chemical composition, crystal structure, defects as well as the local structure environment of Ce3+ in LuBO3: Ce3+ on their scintillation properties will be studied in detail through the synchrotron radiation in-situ X-ray absorption fine structure (XAFS). The implementation of this project will help to elucidate the relationship between crystal structure, phase transition mechanism and scintillation properties, enrich and develop the composition and structure design of scintillators. More importantly, this project will also expand the experimental technology of in-situ high throughput characterization of synchrotron radiation sources for the design and applications of scintillators, and enhance the scientific research capability of national scientific device.

获得具有高密度、高光输出与快衰减等优点的LuBO3:Ce3+闪烁晶体是推动其在核医学成像和高能物理等领域广泛应用的关键环节之一。但LuBO3晶体结构随化学组成的变化规律及相变机理仍不明晰，限制了该晶体的可控生长和应用；目前常规粉末X射线衍射仪无法获得高通量高分辨的晶体结构数据。基于此，本项目拟利用化学组合材料芯片法和梯度浓度晶体生长法进行LuBO3:Ce3+的设计制备与晶体生长，结合与上海同步辐射光源合作开发的原位高通量X射线衍射平台和相稳定性计算，厘清LuBO3:Ce3+的晶体结构和相变机理与化学组成和制备温度的影响机制；结合同步辐射原位X射线吸收谱，揭示化学组成、晶体结构和发光中心Ce3+离子的局域微观环境对闪烁性能的影响规律。本项目的实施对获得优异闪烁性能LuBO3:Ce3+材料、稳定生长出晶体具有重要意义，并有力提升同步辐射原位高通量表征技术在闪烁材料设计合成与应用方面的关键作用。

获得具有高密度、高光输出与快衰减等优点的LuBO3:Ce3+闪烁晶体是推动其在核医学成像和高能物理等领域广泛应用的关键环节之一。但LuBO3晶体结构随化学组成的变化规律及相变机理仍不明晰，限制了该晶体的可控生长和应用，而且常规粉末X射线衍射仪无法获得高通量高分辨的晶体结构数据。为了解决上述这些问题，本项目利用化学组合材料芯片法和浮区法进行Lu1-xScxBO3:Ce3+材料的设计制备与晶体生长，结合与上海同步辐射光源合作开发的原位高通量X射线衍射平台和相稳定性计算软件，获得了Lu1-xScxBO3:Ce3+的晶体结构和相变机理与化学组成和制备温度的影响机制。结合多种光谱表征手段，揭示了化学组成、晶体结构和发光中心Ce3+离子的局域微观环境对闪烁性能的影响规律，并在此基础上进行其他稀土离子掺杂，获得了具有超快衰减时间的稳定LuBO3:Ce3+材料。此外，设计了一套基于同步辐射衍射线站的原位旋涂退火设备，可实现在线完成样品的旋涂、反溶剂、退火及原位晶体结构表征。并针对传统测试方法对薄膜材料下界面不敏感的问题，发展了一个背入射的实验方法，通过引入高透明的柔性衬底，实现X射线从反面穿透柔性衬底并探测背界面的目的，而且使用交互机器人UR5结合3D相机对实验环境进行三维场景建模，在X射线无损检测实验中获得样品不同位置与深度信息的数据。本项目对获得优异闪烁性能LuBO3:Ce3+系列材料具有重要意义，同时提升了同步辐射原位高通量表征技术在闪烁材料的设计合成与应用方面的关键作用。