Recent advances in the field of diffusion in multiprincipal element systems are critically reviewed, with an emphasis on experimental as well as theoretical approaches to determining atomic mobilities (tracer diffusion coefficients) in chemically complex multicomponent systems. The newly elaborated and augmented pseudobinary and pseudoternary methods provide a rigorous framework to access tracer, intrinsic, and interdiffusion coefficients in alloys with an arbitrary number of components. Utilization of the novel tracer-interdiffusion couple method allows for a high-throughput determination of composition-dependent tracer diffusion coefficients. A combination of these approaches provides a unique experimental toolbox to access diffusivities of elements that do not have suitable tracers. The pair-exchange diffusion model, which gives a consistent definition of diffusion matrices without specifying a reference element, is highlighted. Density-functional theory–informed calculations of basic diffusion properties—asrequired for the generation of extensive mobility databases for technological applications—are also discussed.

中文翻译：

---

理解多主元系统扩散的最新进展

批判性地回顾了多主元系统扩散领域的最新进展，重点是确定化学复杂多组分系统中原子迁移率（示踪剂扩散系数）的实验和理论方法。新阐述和增强的伪二元和伪三元方法提供了严格的框架来获取具有任意数量成分的合金中的示踪系数、本征系数和相互扩散系数。利用新型示踪剂相互扩散耦合方法可以高通量测定成分依赖性示踪剂扩散系数。这些方法的组合提供了一个独特的实验工具箱，用于获取没有合适示踪剂的元素的扩散性。突出显示了配对交换扩散模型，该模型在不指定参考元素的情况下给出了扩散矩阵的一致定义。还讨论了密度泛函理论——基本扩散特性的计算——这是为技术应用生成广泛的迁移数据库所需要的。