Feng Jiaqing, Zhang Yiting, Song Xilong, Liu Zixin, Liao Chen, Zhao Lin, Wu Bo, Tao Hong, Ma Jian
Sichuan Province Key Laboratory of Information Materials, Southwest Minzu University, Chengdu, 610225, P. R. China.
Phys Chem Chem Phys. 2024 Sep 25;26(37):24667-24675. doi: 10.1039/d4cp02173h.
The BiFeO-BaTiO solid solution exhibits enhanced electric properties due to its modified phase structure with relaxor characteristics and reduced leakage current. Despite these advancements, the underlying mechanism behind the phase transition from a ferroelectric to a relaxor state in BF-BT ceramics remains largely unexplored. Here, the evolution of strain in (0.67 - )BiFeO-0.33BaTiO-Bi(MgZr)O ceramics is investigated, with a focus on the strain transition from a ferroelectric to a relaxor phase. A strengthening of relaxor behavior is observed in the modified rhombohedral (R) and pseudocubic (P) phase structure, resulting in optimal strain ( = 0.25%, = 0.24%) at = 0.04. The enhanced strain is attributed to the promotion of domain switching and the presence of strong random fields, with polar nanoregions integrating into a long-range ordered matrix. Furthermore, a gradual increase in strain with rising temperature is noted, driven by increased polarization and the expansion of ferroelectric domains. This study underscores the critical role of structural modifications in augmenting the electric response of BF-BT ceramics, thereby advancing the development of lead-free piezoelectric materials.
BiFeO₃-BaTiO₃固溶体由于其具有弛豫特性的改性相结构和降低的漏电流而表现出增强的电学性能。尽管有这些进展，但BF-BT陶瓷中从铁电态到弛豫态的相变背后的潜在机制在很大程度上仍未得到探索。在此，研究了(0.67 - x)BiFeO₃-0.33BaTiO₃-Bi(Mg₁/₂Zr₁/₂)O₃陶瓷中的应变演变，重点是从铁电相到弛豫相的应变转变。在改性的菱面体(R)和假立方(P)相结构中观察到弛豫行为的增强，在x = 0.04时产生最佳应变(ε₃₃ = 0.25%，ε₁₁ = 0.24%)。应变增强归因于畴切换的促进和强随机场的存在，极性纳米区域整合到长程有序矩阵中。此外，注意到随着温度升高应变逐渐增加，这是由极化增加和铁电畴的扩展驱动的。这项研究强调了结构改性在增强BF-BT陶瓷电响应方面的关键作用，从而推动了无铅压电材料的发展。
