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

Qianwei Huang; Jiyuan Yang; Zibin Chen; Yujie Chen; Matthew J Cabral; Haosu Luo; Fei Li; Shujun Zhang; Yulan Li; Zonghan Xie; Houbing Huang; Yiu-Wing Mai; Simon P Ringer; Shi Liu; Xiaozhou Liao

doi:10.1021/acsami.2c14598

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

ACS Appl Mater Interfaces. 2023 Jan 11;15(1):2313-2318. doi: 10.1021/acsami.2c14598. Epub 2022 Dec 19.

Authors

Qianwei Huang¹, Jiyuan Yang^{2

3}, Zibin Chen⁴, Yujie Chen⁵, Matthew J Cabral¹, Haosu Luo⁶, Fei Li⁷, Shujun Zhang⁸, Yulan Li⁹, Zonghan Xie⁵, Houbing Huang¹⁰, Yiu-Wing Mai¹, Simon P Ringer¹, Shi Liu^{2

3}, Xiaozhou Liao¹

Affiliations

¹ School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, New South Wales2006, Australia.
² Key Laboratory for Quantum Materials of Zhejiang Province, Department of Physics, School of Science, Westlake University, Hangzhou, Zhejiang310030, China.
³ Institute of Natural Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang310024, China.
⁴ Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University, Hong Kong, China.
⁵ School of Mechanical Engineering, The University of Adelaide, Adelaide, South Australia5005, Australia.
⁶ Key Laboratory of Inorganic Functional Materials and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai200050, China.
⁷ Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education, Xi'an Jiaotong University, Xi'an710049, China.
⁸ Institute for Superconducting and Electronic Materials, Australian Institute of Innovative Materials, University of Wollongong, Wollongong, New South Wales2522, Australia.
⁹ Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington99352, United States.
¹⁰ School of Materials Science and Engineering, Beijing Institute of Technology, Beijing100081, China.

PMID: 36534513
DOI: 10.1021/acsami.2c14598

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.

Keywords: charged domain walls; domain switching; ferroelectric; strain gradient; transmission electron microscopy.