Extended Data Fig. 5: Strain-field analysis around the CSRO before tensile deformation.

a, Geometric phase analysis strain mapping, superimposed on the lattice image taken with the [110] zone axis. The yellow striped areas with positive strain correspond to the CSROs; two red atoms (V₁ and V₂) are displayed to represent the V-enriched columns. b, Strain distribution between the two V atoms in a. We note that the spacing between the strain peaks of neighbouring V atoms is 0.28 nm. This figure further illustrates the elastic strains observed in Fig. 4. The atomic radii of V, Co, and Ni are 1.35 Å, 1.26 Å and 1.24 Å, respectively. The larger V atoms and the smaller Co/Ni atoms induce tensile and compressive strain, respectively, in the normal direction of close-packed {\(11\bar{1}\)} planes. The yellow striped bands correspond to the CSROs, with tensile (positive) strain induced by the V-enriched columns in the (\(1\bar{1}1\)) plane. Two V atoms (red) are placed in the figure to mark such columns. The strain distribution between these neighbouring columns (V₁ and V₂) is shown in b. The spacing between the two strain peaks is 0.28 nm (the average value is 0.3 nm), quite close to the measured spacing between two atomic columns (0.26 nm) based on TEM lattice image. This corroborates that the yellow regions of positive strain are due to the V-enriched columns associated with the CSRO. Nearby regions (blue) experience compressive strain (negative).