Fig. 6: MD simulations for the origin of MSRO-generated extra scattering in non-equiatomic Fe₄₀Mn₄₀Cr₁₀Co₁₀ (at%) HEA and non-equiatomic NiCrCo MEAs upon loading at 77 K.

a MD-EDPs for the interstitial-free FeMnCrCo structure before and after straining. The [\(\bar{1}\)12] diffraction patterns for the structure before straining show MSRO-derived faint diffuse diffraction scattering at the ½{311} locations, while the relative intensity of MSRO-derived diffuse scattering increased with a higher strain rate. The colour scale (bottom right) defines the relative intensity of diffraction spots in arbitrary units (blue: low intensity; red: high intensity). b Corresponding cell structures strained at 77 K under conditions of different strain rates, showing the distribution of deformation-induced SFs (stacking faults: top panel) and dislocations with different Burgers vectors (bottom panel). The dislocation distribution reveals that strong slip planarity was achieved at higher strain rates. There were no LRO precipitates in all cell structures. This affirms that spot-like scattering at the ½{311} locations in the MD-EDPs directly correlates with SFs and dislocations, but not with LRO structure. The strained cell structures at slow and moderate έ were included in this work for comparison, as the highest έ (2 × 10⁹s^–1) caused severe amorphisation of the system and restricted the observation of the έ effect under equivalent conditions. c Volume fraction of the SFs and dislocations as a function of the strain rate for the non-equiatomic HEA. d MD-EDPs for the strained Ni₆₀Cr₂₀Co₂₀ (at%) MEA, confirming that the relative intensity of MSRO-derived diffuse scattering increased with increasing strain rate. In the MD-EDP for the MEA system before straining, there were no diffuse discs. The strained cell structures, showing the distribution of mechanical SFs and dislocations, are shown in Supplementary Fig. 11. e Volume fraction of the mechanical SFs and dislocations as a function of έ for the MEA. f Increased SF volume fraction with a higher έ for other NiCrCo-based non-equiatomic MEAs with different SFEs. The corresponding strained cell structures and MD-EDPs are shown in Supplementary Fig. 12. The SFEs were determined from the current molecular static simulations at 0 K (see Supplementary Table 1).