Temperature Gradient Introduced Ferroelectric Self‐Poling in BiFeO3 Ceramics
Temperature Gradient Introduced Ferroelectric Self‐Poling in BiFeO3 Ceramics
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DOI：
10.1111/jace.12580
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发表时间：
2013-12
影响因子：
3.9
通讯作者：
Xiaomin Chen;Y. Zou;G. Yuan;M. Zeng;J. Liu;J. Yin;Zhi-guo Liu
中科院分区：
文献类型：
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作者：
Xiaomin Chen;Y. Zou;G. Yuan;M. Zeng;J. Liu;J. Yin;Zhi-guo Liu
所制备的BiFeO 3陶瓷显示出-14 pC/N的压电d33系数，即明显的铁电自极化现象。采用液相快速烧结法制备BiFeO 3陶瓷时，有意增大了BiFeO 3陶瓷两面之间的温度梯度。这种温度梯度和相应的热应变可以通过分离铋空位和氧空位而引入缺陷偶极子。大量的这些偶极子引入宏观内部电场（Ein），其在BiFeO 3陶瓷的冷却过程中向下极化。正如预期的那样，通过不对称的极化/应变对电场曲线证实了>10 kV/cm的Ein。
The as-prepared BiFeO3 ceramic shows a piezoelectric d33 coefficient of −14 pC/N, that is, an obvious ferroelectric self-poling phenomenon. The temperature gradient between the two surfaces of BiFeO3 ceramic was intentionally enlarged when BiFeO3 was prepared with a rapid liquid sintering method. This temperature gradient and the corresponding thermal strain can introduce defect dipoles through separating bismuth vacancies from oxygen vacancies. A mass of these dipoles introduce a macroscopic internal electric field (Ein) which downward poles BiFeO3 ceramic during its cooling down process. As expected, an Ein of >10 kV/cm is confirmed by the asymmetrical polarization/strain versus electric field curves.