Ordered domains in lead free 0.94(Na<sub>0.5sub>Bi<sub>0.5sub>)TiO<sub>3sub>-0.06BaTiO<sub>3sub> ceramics
- 作者：Liu Yunfei<sup> ; sup><sup>yfliu@njut.edu.cnsup><sup> ; sup><sup>lyf2225@163.comsup> ; Lu Yinong<sup> ; sup><sup>ynlu@njut.edu.cnsup> ; Pan Zhigang
- 关键词：HRTEM ; Superlattice reflection ; Ordered domain ; Antiphase boundary
- 刊名：Ceramics International
- 出版年：2012
- 期刊代码：13_02728842
- 类别：ms
- 出版时间：May, 2012
- 卷：38
- 期：4
- 页码：2679-2684
- 文件大小：1531 K
摘要
The microstructure of lead-free 0.94(Na<sub>0.5sub>Bi<sub>0.5sub>)TiO<sub>3sub>-0.06BaTiO<sub>3sub> (BNBT-6) piezoelectric ceramics was investigated by different analysis techniques. X-ray diffraction (XRD) result reveals the coexistence of rhombohedral and tetragonal symmetry in the structure of BNBT-6 ceramics at room temperature. Selected area electron diffraction (SAED) patterns reveal the presence of ordered domains in BNBT-6 ceramics. The superlattice reflections and of ordered domains mainly come from the octahedral tilt and chemical ordering of A-site atoms. High-resolution transmission electron microscopy (HRTEM) combined with image processing is an effective method to investigate the defects and the size of ordered domains in BNBT-6 ceramics. One-dimensional fringe images of superlattice reflections indicate that there are significant local Na and Bi atomic layer displacements and anti-phase boundaries as a result of chemical ordering, which provide a driving force for order-disorder transformation. A filtered HRTEM black/white image shows the size of ordered domains to be about 5-10 nm.