Constructing Relaxor/Ferroelectric Pseudocomposite To Reveal the Domain Role in Electrostrain of Bismuth Ferrite–Barium Titanate Based Ceramics
Bing Li, Ting Zheng, Xiaowei Wei, Shizhao Zhong, Yang Li, Jiagang Wu
Abstract
Bismuth ferrite–barium titanate (BF-BT) based ceramics have attracted extensive attention due to its excellent energy conversion. Recently it has been found that BF-BT based ceramics with large electrostrain are usually accompanied by a special domain configuration in which weak and strong piezoresponse domain grains coexist. In this work, we purposefully constructed the special domain configuration in the pseudocomposite ceramics of (1 – x)0.55BF-0.4BT-0.05BZN/x(0.7BF-0.3BT) (relaxor-like phase/ferroelectric phase, RE/FE) by a “two-step” method. Macroproperty characterization suggests that the critical component pseudocomposite ceramic (x = 50%) with the special domain structure can exhibit a maximum electrostrain value (S ∼ 0.28%) at 6 kV/mm, almost 3-fold to that (S ∼ 0.1%) of the two end members and 63% higher than that (S ∼ 0.17%) of the same component ceramic prepared by the “one-step” method. Further mesoscopic structure results show that the “two-phase” composite can induce the formation of grain dependent domain at nanoscale, and just this special domain conformation is conducive to a significant improvement in electrostrain. Therefore, the large strain in BF-BT-based ceramics is mainly caused by the special microstructure rather than component.