Anomalous Local Lattice Softening around Kink Boundaries in a Mille-Feuille Structured Dilute Mg–Zn–Y Alloy

We have evaluated local elastic properties at kink boundaries in dilute Mg–Zn–Y alloys based on scanning transmission electron microscopy (STEM), first-principles calculations, and geometrical phase analysis (GPA) by measuring atomic-scale strain fields around dislocation cores. STEM observations showed that dislocations constituting are extended into Shockley partial accompanying solute-enriched stacking faults (SESF). Using GPA analysis, we found distributions the cores asymmetric across Mg matrix SESF, showing heterogeneity. Comparison with calculated field model, it is indicated observed profiles essentially caused a softening of matrix. This anomalous can be interpreted as change energy boundary, which may contribute to unique deformation mechanism alloys.