Large Strain in Relaxor/Ferroelectric Composite Lead‐Free Piezoceramics
Large Strain in Relaxor/Ferroelectric Composite Lead‐Free Piezoceramics
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DOI：
10.1002/aelm.201500018
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发表时间：
2015-06
影响因子：
6.2
通讯作者：
Haibo Zhang;C. Groh;Qi Zhang;W. Jo;K. Webber;J. Rödel
中科院分区：
文献类型：
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作者：
Haibo Zhang;C. Groh;Qi Zhang;W. Jo;K. Webber;J. Rödel
研究了一种无铅弛豫(RE)/铁电（FE） 0-3复合材料，该材料在相对较低的4 kV mm−1工作电场下，由电场诱导的遍行弛豫到铁电相变产生了大应变。由70 vol% 0.91Bi1/2Na1/2TiO3-0.06BaTiO3-0.03AgNbO3稀土基体和30 vol% 0.93Bi1/2Na1/2TiO3-0.07BaTiO3 FE种子组成的复合材料在室温下显示出824 pm V−1的归一化应变。为了探索这种复合效应的潜在机制，我们还制备了两层稀土和铁交替层的多层陶瓷，一层与电极表面平行（极化耦合多层），另一层与电极表面垂直（应变耦合多层）。研究发现，除了极化耦合外，应变耦合效应对RE-FE相变场的减小也起着至关重要的作用。在FE/RE界面附近，使用时间依赖的压电显微镜可以突出显示开关动力学。
A lead‐free relaxor (RE)/ferroelectric (FE) 0–3 composite was developed with a large strain that resulted from the electric‐field‐induced ergodic relaxor‐to‐ferroelectric phase transition at a relatively low operational field of 4 kV mm−1. The composite comprised of 70 vol% 0.91Bi1/2Na1/2TiO3–0.06BaTiO3–0.03AgNbO3 RE matrix and 30 vol% 0.93Bi1/2Na1/2TiO3–0.07BaTiO3 FE seed shows a normalized strain, , of 824 pm V−1 at room temperature. In order to explore the underlying mechanism of this composite effect, two multilayer ceramics with alternating RE and FE layers are also prepared, one with the layers parallel (polarization‐coupled multilayer) and the other with the layers perpendicular (strain‐coupled multilayer) to the electroded surfaces. It is found that in addition to polarization coupling, the strain coupling effect also plays a critical role in the reduction of the RE–FE phase transition field. The switching dynamics is highlighted with time‐dependent piezoforce microscopy in the vicinity of the FE/RE interface.