论文标题
固定电压和固定电场处的机电响应之间的广义关系
Generalized relation between electromechanical responses at fixed voltage and fixed electric field
论文作者
论文摘要
我们介绍了无穷小应变的机电耦合与电场的机电耦合与任意顺序，在固定电压和固定电场下测量。我们表明，固定字段的不当响应可以写成为$ n^{\ text {th}} $订单易感性张量的应变衍生物，并且可以将固定电压下降时的适当响应写为固定场的响应加上膨胀和90 $^{\ circt} $旋转。我们的理论正确地再现了适当的压电反应，并且我们超越了电扭曲的响应。我们介绍了在固定场处的不当静脉反应的第一原理计算，并说明了如何使用校正来在固定电压下获得适当的响应。鉴于最近对巨型电折式响应的兴趣，这种区别至关重要，表现出与压电反应一样大的巨型机电响应。
We present a general relation between the electromechanical couplings of infinitesimal strain and electric field to arbitrary order, measured at fixed voltage and at fixed electric field. We show that the improper response at fixed field can be written as the strain derivative of the $n^{\text{th}}$ order susceptibility tensor, and the proper response at fixed voltage drop can be written as the response at fixed field plus corrections for dilations and 90$^{\circ}$ rotations induced by strain. Our theory correctly reproduces the proper piezoelectric response and we go beyond with the electrostrictive response. We present first-principles calculations of the improper electrostrictive response at fixed field, and illustrate how the correction is used to obtain the proper response at fixed voltage. This distinction is of high importance given the recent interest in giant electrostrictors exhibiting electromechanical responses as large as the piezoelectric ones.
