Polarization rotation mechanism for ultrahigh electromechanical response in single-crystal piezoelectrics
Polarization rotation mechanism for ultrahigh electromechanical response in single-crystal piezoelectrics
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DOI：
10.1038/35002022
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发表时间：
2000-01-20
期刊：
影响因子：
64.8
通讯作者：
Cohen, RE
中科院分区：
文献类型：
--
作者：
Fu, HX;Cohen, RE
压电材料将机械能转换为电能（反之亦然），在医学成像，电信和超声设备中至关重要（1，2）。新一代的单晶材料（3），如Pb（Zn 1/3 Nb 2/3）O-3-PbTiO 3（PZN-PT）和Pb（Mg 1/3 Nb 2/3）O-3-PbTiO 3（PMN-PT），表现出比传统陶瓷大十倍的压电效应，并可能彻底改变（4）这些应用。然而，这些新材料的抗氧化性能的机制以及进一步改进的可能性目前尚不清楚。在这里，我们报告了铁电钙钛矿BaTiO 3的第一原理研究，BaTiO 3类似于单晶PZN-PT，但分析起来更简单。我们表明，一个大的压电响应可以驱动由外部电场引起的极化旋转;我们的计算建议如何设计具有更好性能的材料，并可能激发进一步的兴趣在有限电场中的介电系统的基本理论。
Piezoelectric materials, which convert mechanical to electrical energy(and vice versa), are crucial in medical imaging, telecommunication and ultrasonic devices(1,2). A new generation of single-crystal materials(3), such as Pb(Zn1/3Nb2/3) O-3-PbTiO3 (PZN-PT) and Pb(Mg1/3Nb2/3)O-3-PbTiO3 (PMN-PT), exhibit a piezoelectric effect that is ten times larger than conventional ceramics, and may revolutionize(4) these applications. However, the mechanism underlying the ultrahigh performance of these new materials-and consequently the possibilities for further improvements-are not at present clear. Here we report a first-principles study of the ferroelectric perovskite, BaTiO3, which is similar(5) to single-crystal PZN-PT but is a simpler system to analyse. We show that a large piezoelectric response can be driven by polarization rotation induced by an external electric field; Out computations suggest how to design materials with better performance, and may stimulate further interest in the fundamental theory of dielectric systems in finite electric fields.