Li Hongtian, Zhao Jianwei, Li Yong, Chen Longyu, Chen Xiaoxin, Qin Hailan, Zhou Huanfu, Li Peifeng, Guo Jinming, Wang Dawei
College of Materials Science and Engineering, Guilin University of Technology, Guilin 541004, China.
Shenzhen Institute of Advanced Electronic Materials, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China.
ACS Appl Mater Interfaces. 2024 Feb 21;16(7):9078-9087. doi: 10.1021/acsami.3c19340. Epub 2024 Feb 7.
Piezoelectric ceramics, as essential components of actuators and transducers, have captured significant attention in both industrial and scientific research. The "entropy engineering" approach has been demonstrated to achieve excellent performance in lead-based materials. In this study, the "entropy engineering" approach was employed to introduce the morphotropic phase boundary (MPB) into the bismuth ferrite (BF)-based lead-free system. By employing this strategy, a serial of novel "medium to high entropy" lead-free piezoelectric ceramics were successfully synthesized, namely (1-)BiFeO-(BaSrCaBiNa)TiO (BF-BSCBNT, = 0.15-0.5). Our investigation systematically examined the phase structure, domain configuration, and ferroelectric/piezoelectric properties as a function of conformational entropy. Remarkable performances with a largest strain of 0.50% at 100 kV/cm, remanent polarization ∼40.07 μC/cm, coercive field ∼74.72 kV/cm, piezoelectric coefficient ∼80 pC/N, and ∼500 pm/V were achieved in BF-0.4BSCBNT ceramics. This exceptional performance can be attributed to the presence of MPB, coexisting rhombohedral and cubic phases, along with localized nanodomains. The concept of high-entropy lead-free piezoelectric ceramics in this study provides a promising strategy for the exploration and development of the next generation of lead-free piezoelectric materials.
压电陶瓷作为致动器和传感器的关键部件，在工业和科研领域都备受关注。“熵工程”方法已被证明在铅基材料中能实现优异性能。在本研究中，采用“熵工程”方法将准同型相界（MPB）引入到铋铁氧体（BF）基无铅体系中。通过采用该策略，成功合成了一系列新型的“中高熵”无铅压电陶瓷，即(1 - )BiFeO-(BaSrCaBiNa)TiO（BF - BSCBNT，= 0.15 - 0.5）。我们的研究系统地考察了相结构、畴结构以及铁电/压电性能随构象熵的变化。在BF - 0.4BSCBNT陶瓷中实现了显著的性能，在100 kV/cm下最大应变达到0.50%，剩余极化强度约为40.07 μC/cm²，矫顽场约为74.72 kV/cm，压电系数约为80 pC/N，以及约为500 pm/V。这种优异性能可归因于MPB的存在、菱方相和立方相的共存以及局部纳米畴。本研究中高熵无铅压电陶瓷的概念为下一代无铅压电材料的探索和开发提供了一种有前景的策略。
