Fig. 2: Interface dynamics controlling topology selection.

Snapshots of 2D phase-field simulations of dealloying of Ta₁₅Ti₈₅ alloys by Cu₇₀Ti₃₀ (a) and Cu₇₀Ag₃₀ (b) melts illustrating unstable diffusion-coupled growth. Snapshots are shown at different dealloying depths measured from the initial position of the planar solid-liquid interface. The insets illustrate different modes of collisions of liquid channels giving rise to solid ligament pinch off and preservation for Cu₇₀Ti₃₀ and Cu₇₀Ag₃₀ melts, respectively. The domain width of Cu₇₀Ti₃₀ is 1024 nm and Cu₇₀Ag₃₀ is 384 nm. The color bar refers to the Ta concentration and different colors distinguish the liquid region (dark blue), base alloy (light blue), and dealloyed structure (near red). Movies of those simulations highlighting the convoluted paths of penetrating liquid channels during unstable diffusion-coupled growth are given in the Supplementary Movies 2 and 3.