Ultrahigh piezoelectricity in ferroelectric ceramics by design
Ultrahigh piezoelectricity in ferroelectric ceramics by design
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通过设计实现铁电陶瓷的超高压
DOI：
10.1038/s41563-018-0034-4
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发表时间：
2018-04-01
期刊：
影响因子：
41.2
通讯作者：
Zhang, Shujun
中科院分区：
文献类型：
--
作者：
Li, Fei;Lin, Dabin;Zhang, Shujun
压电材料对外加电场产生机械响应，反之亦然，是机电换能器的基本材料。先前的理论分析表明，钙钛矿氧化物中的高压电性与连接两个或更多个铁电相的平坦热力学能量景观相关。在这里，由现象学理论和相场模拟的指导下，我们提出了一种替代的设计策略，常用的morphotropic相边界，以进一步平坦化的能量景观，通过明智地引入局部结构异质性来操纵界面能（即，额外的相互作用能，如静电和弹性能与接口）。为了验证这一点，我们合成了稀土掺杂的Pb（Mg 1/3 Nb 2/3）O3-PbTiO 3（PMN-PT），因为稀土掺杂倾向于改变Pb基钙钛矿铁电体的局部结构。我们在居里温度为89 C的Sm掺杂PMN-PT陶瓷中实现了高达1，500 pC N− 1的压电系数d 33和13，000以上的介电常数ε 33/ε 0。我们的研究为通过工程局部结构异质性设计材料性能提供了一种新的范例，有望使各种功能材料受益。
Piezoelectric materials, which respond mechanically to applied electric field and vice versa, are essential for electromechanical transducers. Previous theoretical analyses have shown that high piezoelectricity in perovskite oxides is associated with a flat thermodynamic energy landscape connecting two or more ferroelectric phases. Here, guided by phenomenological theories and phase-field simulations, we propose an alternative design strategy to commonly used morphotropic phase boundaries to further flatten the energy landscape, by judiciously introducing local structural heterogeneity to manipulate interfacial energies (that is, extra interaction energies, such as electrostatic and elastic energies associated with the interfaces). To validate this, we synthesize rare-earth-doped Pb (Mg 1/3 Nb 2/3) O 3–PbTiO 3 (PMN–PT), as rare-earth dopants tend to change the local structure of Pb-based perovskite ferroelectrics. We achieve ultrahigh piezoelectric coefficients d 33 of up to 1,500 pC N− 1 and dielectric permittivity ε 33/ε 0 above 13,000 in a Sm-doped PMN–PT ceramic with a Curie temperature of 89 C. Our research provides a new paradigm for designing material properties through engineering local structural heterogeneity, expected to benefit a wide range of functional materials.