Spiers Memorial Lecture: Multicomponent and high-entropy materials: an overview.

Area of Science:

• Materials Science
• Solid-State Chemistry
• Computational Materials Design

Background:

• Multicomponent phase space offers vast potential for novel materials discovery.
• Progress in understanding these complex materials has been slow despite significant research efforts.
• High-entropy materials, particularly single-phase solid solutions, are a key focus.

Purpose of the Study:

• To summarize fundamental discoveries regarding the structure of multicomponent phase space.
• To highlight the characteristics and properties of complex materials found within this space.
• To discuss the implications for materials design and application.

Main Methods:

• Review and synthesis of existing research on multicomponent phase space.
• Analysis of structural and property data from studied alloy systems (e.g., Cantor and Senkov alloys).
• Exploration of concepts like configurational entropy and nanostructure variation.

Main Results:

• Identification of numerous single-phase solid-solution phases stabilized by high configurational entropy.
• Observation of extensive local nanostructure variations and lattice strain in these phases.
• Discovery of unusual and valuable properties arising from these complex structures.

Conclusions:

• Multicomponent phase space is rich with complex materials, especially high-entropy single-phase alloys.
• Configurational entropy plays a crucial role in stabilizing these phases.
• Further research is needed, particularly on multiphase multicomponent materials.