Synthesis and Physical Properties of High Entropy Oxide Ceramics

Utilizing entropy as the driving force for stabilizing oxide materials offers a path for the discovery of innovative compounds with unique structure-property relations. The multi-cation approach inherent to high entropy oxides (HEOs) is expected to allow for the tailoring of physical properties that meet the requirements of potential applications. However, the intrinsic disorder and highly localized chemical environments of HEOs bring along new challenges. In order to shed light on the complexities associated multi-cation oxides, we have initiated a systematic study of polycrystalline HEO samples across multiple crystal systems. This work expands the multi-component concept to new compositions and crystal systems and investigates kinetic, magnetic, and elastic properties of materials across multiple crystal systems, including spinel, perovskite, and Ruddlesden-Popper multi-component materials. It contributes to a better understanding of (1) the mechanism of phase formation in HEOs, (2) the effect of various synthesis methods, and (3) the effect of cation disorder on the physical properties.