Fig. 1. Spinodal decomposition and nucleation processes in PZT thin films.

Time evolution of the dipolar pattern within the middle layer of 80 × 80 × 5 film of Pb(Zr_0.4Ti_0.6)O₃ under zero external field (a1–a6) and under 40 × 10⁷ V/m applied along [001] pseudo-cubic direction (b1–b6), as obtained from molecular dynamics simulations. In each of the two cases, 1–6 correspond to 150, 250, 350, 450, 750, and 1500 fs after the quench from 650 K to 10 K, respectively. While a1–a6 indicate the onset of the spinodal instability and development of the labyrinthine pattern, b1–b6 show the nucleation process leading to the bubble domain pattern. Gray (red) dipoles are oriented along [001] ([00$\overline{1}$]) pseudo-cubic direction.