Fabrication of textured Bi ₃NbTiO ₉ ceramics

Highly textured Bi ₃NbTiO ₉ ceramics are fabricated by normal sintering from molten salt-synthesized plate-like crystallites. Fine Bi ₃NbTiO ₉ plate-like crystallites (∼1 μm) not only facilitate the densification, but also enhance texture in Bi ₃NbTiO ₉ ceramics. Weak-agglomerated platelets exhibit higher sinterability and can be densified at a temperature as low as 1000°C, which is about 100°C lower than that of equiaxed powders prepared by directly calcining Bi ₃NbTiO ₉ precursor. Meanwhile, the orientation degree of textured Bi ₃NbTiO ₉ ceramics increases with sintering temperature. Highly oriented Bi ₃NbTiO ₉ (orientation degree of ∼0.91) ceramic with a relative density of ∼92% is obtained at 1150°C. Because of the oriented grain microstructure, textured Bi ₃NbTiO ₉ ceramic exhibits anisotropic electrical properties.