Fig. 4

Domain stability map for Pb(Zr_0.2Ti_0.8)O₃ as a function of the tetragonality of the film (ε_T) and misfit strain (ε_M). The thickness of the film is taken is 100 times larger than the critical thickness for domain formation. α ⁰₃ stands for the equilibrium fraction of c domains. The full blue line separates the (mono) c domain phase (α ⁰₃ = 1) and the a/c/a/c one (0.566 ≤ α ⁰₃ ≤ 1); the green line separates the latter and the a₁/a₂/a₁/a₂ phase (see text). The a/c/a/c phase is metastable for 0 ≤ α ⁰₃ ≤ 0.566 and its limit of metastability is indicated by the red dashed line. The definition of the phases is given in the text