| Abstract Scope |
High-entropy ceramics (HECs) are promising candidates for extreme environments involving intense radiation, corrosive media, high temperatures, and mechanical loading. Key challenges in their design include identifying compositions that form stable single phases within a vast compositional space and establishing links between atomic-scale structure, defect kinetics, and macroscopic performance. In this presentation, we describe newly developed, ab initio–informed and experimentally validated models that enable quantitative prediction of phase stability in HECs. Leveraging these tools, we provide the first direct experimental evidence of chemical short-range order (CSRO) in covalently bonded HECs, extending a concept previously established primarily in metallic systems. We show that CSRO strongly influences radiation tolerance by modulating defect transport and damage accumulation, and that radiation-induced segregation at grain boundaries depends on the degree of CSRO in adjacent grains. Finally, we demonstrate that irradiation simultaneously increases hardness and fracture toughness, breaking the traditional trade-off between these properties. |