Synthesis of high-entropy materials

High-entropy materials (HEMs) exhibit compelling behaviours that are distinct from those in conventional solid solutions. Such disordered multicomponent systems bring unprecedented compositional and structural complexities that hinder a thorough understanding of entropy stabilization and its impact on phase selection and property optimization. The controlled fabrication of HEMs, ideally reaching the same level of detail as traditional alloy design, is desirable. The past decade has witnessed the development of advanced synthesis methodologies and techniques to introduce various degrees of control to this class of inherently disordered materials. Here we discuss the emerging rationales for synthesizing bulk and nanostructured HEMs with tunable microstructures, extended compositions and tailored atomic configurations. Case studies of formation pathways and stabilization mechanisms of different types of HEM reveal insightful synthesis guidelines. This progress enables predictable and rational manipulation of atomic order in the chemically disordered lattice, laying the foundations for exceptional functionalities. The emergence of high-entropy materials affords opportunities to harmonize precision and disorder for materials design. This Review highlights the synthesis principles and strategies towards controllable and predictive fabrication of high-entropy materials with complex chemical compositions, engineered microstructures and tailored atomic configurations.