Local structural disorder introduced by Cr in fcc high-/medium-entropy alloys consisting of 3d transition metal elements.

This article focuses on the element-dependent local structural disorder in high-/medium-entropy alloys (H/MEAs) composed of 3d transition metals, investigated through extended x-ray absorption fine structure (EXAFS) measurements. The study experimentally demonstrates that chromium (Cr) exhibits a consistently larger local disorder, indicated by higher Debye–Waller factors, compared to other constituent elements across seven face-centered cubic H/MEAs. These findings align with prior first-principles calculations showing greater atomic displacements of Cr, which correlate with enhanced yield strength and mechanical properties in these alloys. The authors suggest that the strong attractive interaction between Cr and cobalt (Co) atoms may drive the pronounced displacement of Cr, contributing to the observed local structural disorder.