Mechanically Driven Reversible Polarization Switching in Imprinted BiFeO 3 Thin Films

作者：Yue Wang, Changqing Guo, Mingfeng Chen, Yuhan Liang, Haojie Han, Hetian Chen, Yuanhua Lin, Di Yi, Houbing Huang, Ce‐Wen Nan, Jing Ma · 发表于：Advanced Functional Materials · 年份：2023 · DOI：10.1002/adfm.202213787 · 被引用次数：30 · 研究领域：Ferroelectric and Piezoelectric Materials、Electronic and Structural Properties of Oxides、Ferroelectric and Negative Capacitance Devices

Abstract Mechanically driven polarization switching via scanning probe microscopy provides a valuable voltage‐free strategy for designing ferroelectric nanodomain structures. However, it is still challenging to realize reversible polarization switching with mechanical forces. Here, the mechanically driven reversible polarization switching observed in imprinted ferroelectric BiFeO 3 thin films is reported, i.e., up‐to‐down switching by a sharp scanning tip and down‐to‐up switching by a blunt tip. Free energy calculations, phase‐field simulations, and piezoresponse force microscopy reveal that reversible mechanical switching arises from the interplay among the flexoelectric effect, the piezoelectric effect, and the internal upward built‐in field in BiFeO 3 films. This study gains a deeper insight into the mechanism and control of mechanically driven polarization switching, and provides guidance for exploring potential ferroelectric‐based electro‐mechanical microelectronics.