Quantifying Solid-State Diffusion in Lanthanide-Doped NaYF4 Core–Shell Nanocrystals by Anomalous Small-Angle X-ray Scattering

We will investigate lanthanide-ion diffusion in NaYF₄ core–shell nanocrystals, a widely used host for luminescent applications. While the shell protects the doped core from surface-induced quenching, high-temperature processing can drive ion migration across the interface, reducing efficiency. Understanding this diffusion is essential both for optimizing luminescence performance and for enabling applications such as thermal-history sensing. Luminescence-based methods are sensitive to ion distribution but are difficult to interpret due to environmental quenching. In contrast, anomalous small-angle X-ray scattering (ASAXS) provides quantitative, element-specific concentration profiles as a function of temperature, time, and ionic radius. These measurements will also establish a benchmark for refining optical screening techniques for routine diffusion analysis.

本研究将针对氟化钇钠（NaYF₄）核壳纳米晶中的镧系离子扩散展开探究——该材料是发光应用领域中广泛使用的基质材料。尽管壳层可保护掺杂核免受表面诱导猝灭效应的影响，但高温制程会驱使离子在界面处发生迁移，进而降低发光效率。明晰该扩散过程，对于优化发光性能以及实现热历史传感等应用而言均至关重要。基于发光原理的检测方法对离子分布具有敏感性，但受环境猝灭效应影响，其结果往往难以解读。与之相比，反常小角X射线散射（Anomalous Small-Angle X-ray Scattering，ASAXS）可提供定量且元素特异性的浓度分布曲线，该曲线可表示为温度、时间与离子半径的函数。此类测量结果还将为优化用于常规扩散分析的光学筛选技术建立基准参照。