Fig. 2.

Metallic glass–approximant–QC transition. (A) Metallic glass to QC transition in an as-cast Mg₆₄Zn₂₇Yb₉ alloy shown from a cross-section perpendicular to the mold wall. (B) A magnified backscattered electron SEM image of the region indicated by a rectangle in A. (C) Scanning TEM image of the microstructure of a lamella extracted from the region indicated by the rectangle in B (electron diffraction patterns of particles, in SI Appendix, Fig. S1, demonstrate the formation of an approximant phase, i.e., Mg₅₁Zn₂₀ type). The cooling rate decreases from left to right for all micrographs.