Property Regulation Principle in Mn‐Doped BF–BT Ceramics: Competitive Control of Domain Switching By Defect Dipoles and Domain Configuration

Abstract Mn‐doping is reported to be an effective strategy to obtain better electrical property in bismuth ferrite‐barium titanate (BF‐BT)‐based ceramics, while the property regulation principle and its potential physical mechanism is still poorly understood. For disclose the veil of Mn‐doping enhancing properties, the typical material system BF‐BT– x MnO 2 mol% is designed and the effects of Mn‐doping on multilevel structures and external fields stimulated electrical properties are deeply investigated. Mn‐doping induced structure disorder and defect dipoles lead to the formation of nanodomain and the variation of local structure, contributing to intrinsic enhancement of polarization. Especially, electrical properties under different electric and temperature fields reveal that there is a competitive control of domain switching by defects and domain configuration, which is also verified by domain writing technology and switching spectroscopy piezore‐sponse force microscopy. That is, the defect dipoles have pinning effect on domain to hinder domain switching, leading to smaller polarization and indistinctive electrostrain at low fields. While the nanodomain reduces intrinsic coercive field and promotes domain switching, generating much larger polarization and electrostrain at high fields. lt is believed the decoding of domain switching behavior controlled by defect and domain can provide a paradigm to understand the property evolution in chemically modified BF‐BT.