Lee Ji Hye, Kim Hong Joon, Yoon Jiyong, Kim Sanghyeon, Kim Jeong Rae, Peng Wei, Park Se Young, Noh Tae Won, Lee Daesu
Center for Correlated Electron Systems, Institute of Basic Science, Seoul 08826, Korea.
Department of Physics and Astronomy, Seoul National University, Seoul 08826, Korea.
Phys Rev Lett. 2022 Sep 9;129(11):117601. doi: 10.1103/PhysRevLett.129.117601.
Flexoelectricity-based mechanical switching of ferroelectric polarization has recently emerged as a fascinating alternative to conventional polarization switching using electric fields. Here, we demonstrate hyperefficient mechanical switching of polarization exploiting metastable ferroelectricity that inherently holds a unique mechanical response. We theoretically predict that mechanical forces markedly reduce the coercivity of metastable ferroelectricity, thus greatly bolstering flexoelectricity-driven mechanical polarization switching. As predicted, we experimentally confirm the mechanical polarization switching via an unusually low mechanical force (100 nN) in metastable ferroelectric CaTiO_{3}. Furthermore, the use of low mechanical forces narrows the width of mechanically writable nanodomains to sub-10 nm, suggesting an ultrahigh data storage density of ≥1 Tbit cm^{-2}. This Letter sheds light on the mechanical switching of ferroelectric polarization as a viable key element for next-generation efficient nanoelectronics and nanoelectromechanics.
基于挠曲电效应的铁电极化机械切换最近已成为一种引人入胜的替代方案，可替代使用电场的传统极化切换。在此，我们展示了利用具有独特机械响应的亚稳铁电性实现的超高效极化机械切换。我们从理论上预测，机械力会显著降低亚稳铁电性的矫顽力，从而极大地增强挠曲电效应驱动的机械极化切换。正如预测的那样，我们通过在亚稳铁电体钛酸钙中施加异常低的机械力（100 nN），实验证实了机械极化切换。此外，使用低机械力可将机械可写入纳米畴的宽度缩小至亚10 nm，这表明具有≥1 Tbit cm⁻²的超高数据存储密度。这封信揭示了铁电极化的机械切换作为下一代高效纳米电子学和纳米机电学的可行关键元件。
