Preparation of textured Bi3TiNbO9 ceramics

Single phase of textured Bi3TiNbO9 (BTNO) ceramics were prepared by a two-step sintering method: synthesizing seed-crystal platelets by molten-salt method with oxide mixture as precursor and then sintering the platelets via hot-pressing method. Molten-salt-synthesized fine BTNO plate-like crystallines (∼400 nm) had an orientation degree of 0.42. After hot-pressed under different conditions, textured BTNO ceramics with different orientation degree were obtained and the orientation degree of textured BTNO ceramics increased with the applied pressure as well as the sintering temperature. X-ray diffraction (XRD) patterns of textured BTNO revealed that the face perpendicular to the hot-pressing axis (⊥) exhibits stronger (0 0 l) diffraction peaks, while the face parallel to the hot-pressing axis (∥) shows stronger (0 2 0)/(2 0 0) and weaker (0 0 l) diffraction peaks, which also can be apparently observed from SEM images. Highly oriented BTNO with a degree of 0.78 was obtained under an applied pressure of 60 MPa at 1050 °C.