High-entropy oxide ceramics as structural and barrier-coating materials

High-entropy oxide ceramics (HEOCs) hold promising potential for diverse applications, as their properties can be precisely tailored through the strategic selection of elements and adjustment of doping ratios. While structural and coating materials represent the most widespread and fundamental applications of high-entropy materials, comprehensive reviews focusing on these domains remain scarce. In this Perspective, we highlight diverse structural and coating oxide ceramics that have emerged since the discovery of high-entropy ceramics. Despite the relatively short history of high-entropy materials, we analyze classic-case studies that correlate phase structures with performance, systematically compiling and contrasting findings to guide future research. An overview of intrinsic properties in these cases, such as crystal structures, synthesis methodologies, mechanical properties, and thermal-insulation capabilities, is given and presented visually through images and tables. This synthesis not only clarifies the current landscape but also establishes a framework for advancing high-entropy ceramic studies, providing a foundational reference for researchers exploring novel material designs and applications.