| Abstract Scope |
High-entropy ceramics (HECs), particularly carbides and borides, are a promising new class of materials for extreme environments involving radiation, corrosion, high temperatures, and mechanical stress. In this talk, we present our recently developed ab initio-based, experimentally-validated models that accurately predict phase stability of HECs. We demonstrate the first direct evidence of chemical short-range order (CSRO) in covalently-bonded HECs, a phenomenon well documented in metals but previously unconfirmed in covalent ceramics. We show that CSRO significantly influences radiation tolerance of HECs by modulating defect diffusivities. Furthermore, we reveal that CSRO at grain boundaries evolves due to radiation-induced segregation (RIS), and that the extent of RIS depends on the CSRO within crystalline grains. These findings establish fundamental connections between local chemical order, defect dynamics, and macroscopic properties in HECs, offering new pathways for the design of advanced structural materials. |