Ferroelectric Instability and Dimensionality in Bi-Layered Perovskites and Thin Films

Figure 12

Crystal structures of (a) the paraelectric and (b) the ferroelectric phases of layered perovskite SrBi₂Ta₂O₉. Arrows show estimated dipole arrangements of TaO₆ octahedra [25].

(a)

(b)