Morphology evolution of lead-free ceramics: formation of Bi0.5Na0.5TiO3superstructures on a Ti substrate

Bi0.5Na0.5TiO3 (BNT) piezoelectric superstructures were successfully synthesized by hydrothermal methods and characterized by X-ray diffraction, Scanning and Transmission Electron Microscopy. The effects of preparation conditions, such as temperature and reaction time, on the morphology of BNT were investigated. BNT superstructures are formed after holding at 200 °C for 10 h and at 180 °C for 24 h, indicating that high temperature is beneficial in reducing holding time. The XRD results indicated that the crystals of BNT presented preferred orientation; TEM images and XRD results indicated that the BNT grains grew along three directions ([010], [100] and [001]) to form the particular architecture.