Preparation and ferroelectric properties of the AIIBi3Ti2NbO12 (AII = Sr, Pb) layered Perovskite-like oxides

SrBi3Ti2NbO12 and PbBi3Ti2NbO12 ceramics were prepared by hot pressing. Both oxides were found to have a layered perovskite-like structure(a = b = 3.850 A,c = 33.21 A in the former anda = b = 3.865 A,c = 33.52 A in the latter) and undergo ferroelectric phase transitions at Tc = 441 and 570 K, respectively. The dielectric constants of the ceramics are, respectively, 440 and 217 at room temperature and 600 and 870 at Tc.