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

Table 1

Positional and thermal parameters of ferroelectric phase (A2₁am) of SrBi₂Ta₂O₉ at 300 K [25].

Atom	𝑥	𝑦	𝑧	𝐵eq
Sr	0	0.2610	0	0.69 (1)
Bi	0.4833 (14)	0.7738 (4)	0.2011 (1)	1.77 (1)
Ta	0.5177 (16)	0.7468 (6)	0.4143 (1)	0.37 (1)
O(1)	0.5365 (89)	0.3335 (67)	0	1.04 (5)
O(2)	0.4904 (72)	0.7316 (49)	0.3402 (4)	1.55 (4)
O(3)	0.7057 (76)	0.0146 (130)	0.2623 (5)	0.85 (4)
O(4)	0.7523 (94)	0.0002 (101)	0.0730 (6)	0.62 (5)
O(5)	0.7854 (87)	0.9744 (93)	0.5850 (6)	0.91 (4)