Composition-dependent structure and properties of 5- and 15-element high-entropy alloy nanoparticles

Summary High-entropy alloy nanoparticles (HEA NPs) are an area of interest due to their interesting structural features, large compositional space, and high potential for catalytic applications. While many HEA NPs have been successfully synthesized and characterized, little is known about the impact of composition on structural features. This work utilizes element-specific X-ray spectroscopy techniques to compare 5- and 15-element HEA NPs with shared elements, aiming to understand the impact that adding additional elements to an HEA has on its structure and properties. Here, we report significant differences between HEA-5 and HEA-15. In particular, the 3d elements show different oxidation behavior associated with different bonding properties. Varied bonding properties are also observed in the 4d and 5d elements. These results provide an understanding of the impact composition plays on the HEA structure, which will serve to aid in the fine-tuning of structure and properties of HEAs through adjusting their composition.