Ferroelectric Mesocrystals of Bismuth Sodium Titanate: Formation Mechanism, Nanostructure, and Application to Piezoelectric Materials

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• 作者：Dengwei Hu ; Xingang Kong ; Kotaro Mori ; Yasuhiro Tanaka ; Kazunari Shinagawa ; Qi Feng
• 刊名：Inorganic Chemistry
• 出版年：2013
• 出版时间：September 16, 2013
• 年：2013
• 卷：52
• 期：18
• 页码：10542-10551
• 全文大小：702K
• 年卷期：v.52,no.18(September 16, 2013)
• ISSN：1520-510X

文摘

Ferroelectric mesocrystals of Bi_0.5Na_0.5TiO₃ (BNT) with [100]-crystal-axis orientation were successfully prepared using a topotactic structural transformation process from a layered titanate H_1.07Ti_1.73O₄路nH₂O (HTO). The formation reactions of BNT mesocrystals in HTO鈥揃i₂O₃鈥揘a₂CO₃ and HTO鈥揟iO₂鈥揃i₂O₃鈥揘a₂CO₃ reaction systems and their nanostructures were studied by XRD, FE-SEM, TEM, SAED, and EDS, and the reaction mechanisms were given. The BNT mesocrystals are formed by a topotactic structural transformation mechanism in the HTO鈥揃i₂O₃鈥揘a₂CO₃ reaction system and by a combination mechanism of the topotactic structural transformation and epitaxial crystal growth in the HTO鈥揟iO₂鈥揃i₂O₃鈥揘a₂CO₃ reaction system, respectively. The BNT mesocrystals prepared by these methods are constructed from [100]-oriented BNT nanocrystals. Furthermore, these reaction systems were successfully applied to the fabrication of [100]-oriented BNT ferroelectric ceramic materials. A BNT ceramic material with a high degree of orientation, high relative density, and small grain size was achieved.