Enhancement of ferroelectric properties, both spontaneous polarization and Curie temperature under negative pressure had been predicted in the past from first principles and recently confirmed experimentally. In contrast, piezoelectric properties are expected to increase by positive pressure, through polarization rotation. Here we investigate the piezoelectric response of the classical PbTiO3, Pb(Zr,Ti)O3 and BaTiO3 perovskite ferroelectrics under negative pressure from first principles and find significant enhancement. Piezoelectric response is then tested experimentally on free-standing PbTiO3 and Pb(Zr,Ti)O3 nanowires under self-sustained negative pressure, confirming the theoretical prediction. Numerical simulations verify that negative pressure in nanowires is the origin of the enhanced electromechanical properties. The results may be useful in the development of highly performing piezoelectrics, including lead-free ones.

中文翻译：

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负压下的压电增强。

过去已经根据第一原理预测了铁电性质，自发极化和居里温度在负压下的增强，并且最近通过实验得到了证实。相反，期望压电性能通过极化旋转通过正压增加。在这里，我们从第一原理出发，研究了负压下经典PbTiO3，Pb（Zr，Ti）O3和BaTiO3钙钛矿铁电体的压电响应，并发现了显着的增强。然后在自持负压下在独立的PbTiO3和Pb（Zr，Ti）O3纳米线上对压电响应进行了实验测试，证实了理论预测。数值模拟证明，纳米线中的负压是增强的机电性能的起源。