Nanosized high-entropic materials based on HEA, design principles and synthesis methods

Abstract

The principles of designing high-entropy alloys related to the selection of elements are analyzed. When selecting elements, a parametric approach is used, including chemical and topological parameters. The main chemical parameter is the enthalpy of mixing of elements, the main topological parameter is the atomic radius. It is emphasized that the use of modified atomic radii (which take into account the local electronic environment) better predicts the formation of either amorphous or crystalline high-entropy alloys. Four main effects that determine the properties of high-entropy alloys are considered: the high entropy effect, the lattice distortion effect, the delayed diffusion effect, and the «cocktail» effect. Obtaining nanosized high-entropy materials based on high-entropy alloys is a new promising direction that allows one to significantly expand their areas of application related to energy (catalysis, energy storage, etc.), nanoelectronics, etc. The article analyzes some methods for the synthesis of nanosized high-entropy alloys and materials based on them. basis, developed as catalysts. The improved performance over conventional catalysts is explained in terms of the effects and features specific to multicomponent systems.

Keywords

• multicomponent
• amorphous and nanocrystalline alloys
• high-entropy alloys and nanosized high-entropy alloys
• morphology
• catalysts
• fcc and hcp structures
• bcc
• strength
• thermal stability