Formation of Head/Tail-to-Body Charged Domain Walls by Mechanical Stress

Abstract

Domain walls (DWs) in ferroelectric materials are interfaces that separate domains with different polarizations. Charged domain walls (CDWs) and neutral domain walls are commonly classified depending on the charge state at the DWs. CDWs are particularly attractive as they are configurable elements, which can enhance field susceptibility and enable functionalities such as conductance control. However, it is difficult to achieve CDWs in practice. Here, we demonstrate that applying mechanical stress is a robust and reproducible approach to generate CDWs. By mechanical compression, CDWs with a head/tail-to-body configuration were introduced in ultrathin BaTiO3, which was revealed by in-situ transmission electron microscopy. Finite element analysis shows strong strain fluctuation in ultrathin BaTiO3 under compressive mechanical stress. Molecular dynamics simulations suggest that the strain fluctuation is a critical factor in forming CDWs. This study provides insight into ferroelectric DWs and opens a pathway to creating CDWs in ferroelectric materials.

A rigid–soft hybrid paper-based flexible pressure sensor with an ultrawide working range and frequency bandwidth

“…Thus, the sensor has a maximum sensing pressure of 1 MPa. The bioinspired paper-based pressure sensor fabricated here shows an extremely wide pressure-sensing range when compared to the other reported paper-based pressure sensors 24,25,29,30,[37][38][39][40][41] (Table S1 † and Fig. 3e).…”