High-entropy materials (HEMs), which prominently include high-entropy alloys (HEAs), represent a revolutionary paradigm shift in materials science. Unlike traditional metallurgical design—which relies on a single base element (like iron in steel) mixed with minor additives—HEMs are composed of five or more principal elements mixed in equal or near-equal proportions (typically 5% to 35% each).

The Four Core Effects The unique and highly tunable behavior of HEMs is governed by four fundamental principles:

1. The High-Entropy Effect: The high number of elements maximizes configurational entropy. Thermodynamically, this stabilizes simple, disordered solid-solution crystal structures (like FCC, BCC, or HCP) rather than forming brittle and complex intermetallic compounds.
2. Severe Lattice Distortion: Because the constituent elements ...