Temperature-insensitive large electrostrains and electric field induced intermediate phases in (0.7 − x)Bi(Mg1/2Ti1/2)O3-xPb(Mg1/3Nb2/3)O3-0.3PbTiO3 ceramics
Temperature-insensitive large electrostrains and electric field induced intermediate phases in (0.7 − x)Bi(Mg1/2Ti1/2)O3-xPb(Mg1/3Nb2/3)O3-0.3PbTiO3 ceramics
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DOI：
10.1016/j.jeurceramsoc.2014.07.017
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发表时间：
2014-12
影响因子：
5.7
通讯作者：
Wanli Zhao;R. Zuo;Fu Jian
中科院分区：
文献类型：
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作者：
Wanli Zhao;R. Zuo;Fu Jian
在BMT-PT-PMN三元系统的准同型相界附近，新的（0.7 −x）Bi（Mg 1/2 Ti 1/2）O3-xPb（Mg 1/3 Nb 2/3）O3-0.3PbTiO3（（0.7 −x）BMT-xPMN-0.3PT）陶瓷（x = 0.0-0.7）的大电应变（在7 kV/mm下为0.4%）被发现与组分调制介电弛豫行为的演变有关。正如原位高分辨率同步辐射X射线衍射所揭示的那样，由外场诱导的不同对称性的更多中间相在很大程度上有助于使富含PMN的组合物的应变滞后（约23%）比富含BMT的组合物的应变滞后小。特别是，x = 0.2的样品在5 kV/mm下的温度不敏感电应变为10.3%，从室温到160 °C变化小于10%，这主要归因于两种弛豫态在宽温度范围内共存，这是由于富含BMT的组合物特有的静态畴结构。这些发现提供了一种新的方法，对一个适当的组成设计的低滞后温度不敏感的大电应变的BMT基弛豫铁电体。
Large electrostrains (∼0.4% at 7 kV/mm) of the new (0.7 −x)Bi(Mg1/2Ti1/2)O3–xPb(Mg1/3Nb2/3)O3–0.3PbTiO3((0.7 −x)BMT–xPMN–0.3PT) ceramics withx= 0.0–0.7 near the morphotropic phase boundary of the BMT–PT–PMN ternary system were found to be associated with the evolution of the compositionally modulated dielectric relaxor behavior. As disclosed by in situ high-resolution synchrotron X-ray diffraction, more intermediate phases of different symmetries induced by external fields largely contribute to smaller strain hysteresis (∼23%) of PMN-rich compositions than BMT-rich ones. Particularly, thex= 0.2 sample exhibits temperature-insensitive electrostrains of ∼0.3% at 5 kV/mm varying less than 10% from room temperature up to 160 °C, which is mainly attributed to the coexistence of two kinds of relaxor states in a broad temperature range owing to special static domain structures typical for BMT-rich compositions. These findings provide a new approach toward an appropriate compositional design for low-hysteresis temperature-insensitive large electrostrains in BMT-based relaxor ferroelectrics.