Polar domain structural evolution under electric field and temperature in the (Bi0.5Na0.5)TiO3-0.06BaTiO(3) piezoceramics
Polar domain structural evolution under electric field and temperature in the (Bi0.5Na0.5)TiO3-0.06BaTiO(3) piezoceramics
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(Bi0.5Na0.5)TiO3-0.06BaTiO(3)压电陶瓷在电场和温度下的极域结构演化
DOI：
10.1111/jace.15883
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发表时间：
2019
影响因子：
3.9
通讯作者：
Ye Zuo Guang
中科院分区：
文献类型：
--
作者：
Zhao Jinyan;Zhang Nan;Ren Wei;Niu Gang;Walker David;Thomas Pamela A;Wang Lingyan;Ye Zuo Guang
无铅钛酸铋钠和相关化合物作为压电应用的有前途的候选者受到极大关注。然而，对这一系列材料的充分理解仍然是一个挑战，部分原因是它们的结构复杂性和在施加或不施加外部电场的情况下的不同行为。在此，利用压电响应力显微镜对（1-x）Bi0.5Na0.5TiO3-xBaTiO 3（x =0.06）固溶体（简称BNT-6 BT）的准同型相界（MPB）组成的介观尺度畴结构进行了深入研究。结合晶体结构分析和介电性能研究，对电畴随电场和温度变化的演化规律进行了深入研究。结果表明，在介观尺度上，铁电畴以弛豫态存在，尺寸为几百纳米，没有明显的畴结构，这两种畴结构分别对材料中的四方相和立方相有贡献。在室温至200°C的非极化样品中观察到与温度无关的畴结构。同时，在极化样品中观察到温度依赖的畴结构。在所谓的退极化温度附近，均匀极化态断裂成包含多畴结构和不可见态的混合畴结构。文中还讨论了不同长度尺度上的结构变化。这项工作提供了对MPB组合物的BNT-BT固溶体中在电场下的结构和畴变化以及非极化和极化状态下的温度依赖性畴演化的深入理解。
Lead‐free bismuth sodium titanate and related compounds are of great interest as promising candidates for piezoelectric applications. However, the full understanding of this family of materials is still a challenge partly because of their structural complexity and different behaviors with or without the application of an external electric field. Here, piezoresponse force microscopy is used to gain insight into the mesoscopic‐scale domain structure of the morphotropic phase boundary (MPB) composition of (1‐x)Bi0.5Na0.5TiO3‐xBaTiO3solid solution atx=0.06 (abbreviated as BNT‐6BT). The evolution of the domains with the changes of the electric field and temperature has been thoroughly examined in conjunction with the crystal structure analysis and dielectric studies. It is found that ferroelectric domains with size of hundreds of nanometers are embedded in a relaxor state without visible domains on a mesoscopic scale, which are considered to contribute to the tetragonal and cubic phases in the material, respectively. Temperature‐independent domain configuration is observed in the unpoled sample from room temperature to 200°C. While, temperature‐dependent domain configuration is observed in the poled sample. The homogenously poled state breaks into the mixed domain configuration containing polydomain structure and invisible state around the so‐called depoling temperature. The structural changes on different length scales are also discussed. This work provides an in‐depth understanding of the structural and domain changes under an electric field and the temperature‐dependent domain evolution in both unpoled and poled states in the BNT‐BT solid solution of the MPB composition.