Local Characterization of High Entropy Materials Using X-Ray Absorption Fine Structure Spectroscopy

The properties we observe in materials are a direct consequence of their composition and local structure. High entropy materials are a unique class of systems that do not have a primary composition; rather they contain a near-equimolar distribution of several elements— where no single element serves as host. Such compositional disorder is accompanied by a unique distribution of localized structural distortions that can have a profound effect on properties such as thermal conductivity, magnetic interaction, diffusion, and more. To date, high entropy metals and ceramics are gaining significant traction in the materials community as unique and interesting properties continue to emerge, from amorphous-like thermal conductivities to exotic magnetic states. In this talk, we discuss the local characterization of several high entropy compositions exhibiting structures from rocksalts to Kagome lattices. In particular, the use of X-ray absorption fine structure (XAFS) is demonstrated to aid in understanding such disorder on the local level and how it may influence functional properties.