Negative capacitance (NC) in ferroelectric materials has been proposed to overcome the fundamental limitation on the energy efficiency of electronics. Understanding the impact of mechanical strain on the NC of ferroelectrics is of scientific significance and technological importance because the strain-polarization coupling could substantially influence the multifunctional properties of epitaxial ferroelectric thin films. Based on time-dependent Ginzburg-Landau equation and Kirchhoff's law, we reveal that a tensile strain decreases the magnitude and duration time of the transient NC of PbZr_(1-x)Ti_xO₃ (PZT) thin films while a compressive strain increases it in a resistor-ferroelectric capacitor circuit. In particular, the tensile strain makes the transient NC completely disappear near the morphotropic phase boundary (MPB), whereas the compressive strain can maintain it up to a temperature higher than Curie temperature. The detailed energy analysis reveals that the change of transient NC with strain and composition is attributed to the change of the negative curvature of energy landscape, which is the origin of NC in ferroelectric materials. The work gives considerable new insight into the mechanical control of ferroelectric transient NC, and offers guidance in searching for large transient NC in the widely used PZT thin films through strain and composition engineering.

已经提出了铁电材料中的负电容（NC）以克服对电子器件的能量效率的基本限制。了解机械应变对铁电体NC的影响具有科学意义和技术重要性，因为应变-极化耦合可能会极大地影响外延铁电薄膜的多功能性能。基于时间相关的Ginzburg-Landau方程和基尔霍夫定律，我们发现拉伸应变降低了PbZr _{（1- x）} Ti _x O ₃瞬态NC的大小和持续时间。（PZT）薄膜，而在电阻器-铁电电容器电路中，压缩应变使薄膜增大。特别是，拉伸应变使瞬态NC在同相相界（MPB）附近完全消失，而压缩应变可以使其保持在高于居里温度的温度。详细的能量分析表明，瞬态NC随应变和成分的变化归因于能态负曲率的变化，这是铁电材料中NC的起源。这项工作为铁电瞬态NC的机械控制提供了相当多的新见解，并为通过应变和成分工程在广泛使用的PZT薄膜中寻找大型瞬态NC提供了指导。