Large electromechanical strain at high temperatures of novel textured BiFeGaO3-BaTiO3 based ceramics
Large electromechanical strain at high temperatures of novel textured BiFeGaO3-BaTiO3 based ceramics
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DOI：
10.1016/j.jmst.2019.12.033
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发表时间：
2020-07
影响因子：
10.9
通讯作者：
J. Peng;Wenbing Liu;Jiangtao Zeng;Liaoying Zheng;Guorong Li;A. Rousseau;A. Gibaud;A. Kassiba
中科院分区：
文献类型：
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作者：
J. Peng;Wenbing Liu;Jiangtao Zeng;Liaoying Zheng;Guorong Li;A. Rousseau;A. Gibaud;A. Kassiba
BiFeGaO3-BaTiO3(BFG-BT)基陶瓷具有大压电系数，是潜在的高性能无铅压电材料。在这项工作中，通过固相反应方法在有和没有BaTiO3(BT)模板的情况下实现了织构和随机BFG-BT陶瓷。通过反应模板晶粒生长 (RTGG) 方法获得织构化陶瓷，该方法在 40 kV/cm 下的高温机电应变为 S= 0.27 %，在 180 °C 下的有效压电系数 (d33*) 高达 685 pm/V。定向域的轻松移动增强了纹理样品中施加电场下的机电应变（Lotgering Factorf= 66.3 %）。结构研究表明，BFG-BT菱面体相（R3c）的变形比例和变形程度在织构陶瓷中达到最大值，导致电场下产生大的铁变形位移。此外，从高分辨率透射电子显微镜（HR-TEM）观察推断，具有低畴壁能量的致密纳米域有助于纹理化样品在施加电场下的额外位移。在织构陶瓷中，从室温到180°C，残余极化保持稳定（约17μC/cm2），有助于在高温下保持稳定的铁电性能。通过引入 BT 模板，形成了高密度纳米域，并提高了织构陶瓷的烧伤温度。机电应变、极化和介电行为与 BFG-BT 基陶瓷的纹理或随机形式相关。
BiFeGaO3-BaTiO3(BFG-BT) based ceramics with a large piezoelectric coefficient are potential high performance lead-free piezoelectric compounds. In this work, textured and random BFG-BT ceramics were realized by the solid state reaction method with and without BaTiO3(BT) templates. Textured ceramics were obtained by a reactive templated grain growth (RTGG) method leading to a high-temperature electromechanical strain ofS= 0.27 % at 40 kV/cm and to an effective piezoelectric coefficient (d33*) up to 685 pm/V at 180 °C. The easy movement of oriented domains enhanced the electromechanical strain under an applied electric field in textured sample (Lotgering factorf= 66.3 %). Structural investigations reveal that the proportion and degree of distortion of BFG-BT rhombohedral phase (R3c) reached its maximum in textured ceramics, resulting in large ferrodistortive displacements under electric fields. In addition, the dense nanodomains with low domain wall energies, inferred from the high-resolution transmission electron microscope (HR-TEM) observations, contribute to the extra displacement of the textured sample under an applied electric field. In textured ceramics, the remnant polarization was stable (about 17 μC/cm2) from room temperature to 180 °C, contributing to the stable ferroelectric property at high temperatures. Through the introduction of BT templates, high-density nanodomains were formed and the Burns temperature was enhanced in textured ceramics. The electromechanical strain, polarization and dielectric behavior were correlated to the textured or random forms of the BFG-BT based ceramics.