Li Tianyu, Yang Jiyuan, Deng Shiqing, Wang Zhen, Tang Mingxue, Luo Huajie, Long Feixiang, Chen Yu, Wang Jia-Ou, Wang Huanhua, Xu Shuai, Guo Er-Jia, Jin Kui-Juan, Qi He, Diéguez Oswaldo, Liu Shi, Chen Jun
Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083, China.
Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing 100083, China.
J Am Chem Soc. 2024 Jul 24;146(29):20205-20212. doi: 10.1021/jacs.4c05281. Epub 2024 Jul 15.
Incipient ferroelectrics have emerged as an attractive class of functional materials owing to their potential to be engineered for exotic ferroelectric behavior, holding great promise for expanding the ferroelectric family. However, thus far, their artificially engineered ferroelectricity has fallen far short of rivaling classic ferroelectrics. In this study, we address this challenge by developing a superfine nanodomain engineering strategy. By applying this approach to representative incipient ferroelectric of SrTiO-based films, we achieve unprecedentedly strong ferroelectricity, not only surpassing previous records for incipient ferroelectrics but also being comparable to classic ferroelectrics. The remanent polarization of the thin film reaches up to 17.0 μC cm with an ultrahigh Curie temperature of 973 K. Atomic-scale investigations elucidate the origin of this robust ferroelectricity in the emergent high-density superfine nanodomains spanning merely 3-10 unit cells. Combining experimental results with theoretical assessments, we unveil the underlying mechanism, where the intentionally introduced diluted foreign Fe element creates a deeper Landau energy well and promotes a short-range ordering of polarization. Our developed strategy significantly streamlines the design of unconventional ferroelectrics, providing a versatile pathway for exploring new and superior ferroelectric materials.
由于具有被设计用于呈现奇异铁电行为的潜力，初发铁电体已成为一类引人注目的功能材料，有望扩展铁电体家族。然而，到目前为止，它们的人工工程铁电性远不及经典铁电体。在本研究中，我们通过开发一种超精细纳米畴工程策略来应对这一挑战。通过将这种方法应用于基于SrTiO的薄膜这一代表性初发铁电体，我们实现了前所未有的强铁电性，不仅超过了初发铁电体的先前记录，而且与经典铁电体相当。薄膜的剩余极化高达17.0 μC/cm²，居里温度高达973 K。原子尺度的研究阐明了这种强大铁电性的起源，其源于仅跨越3 - 10个晶胞的新兴高密度超精细纳米畴。将实验结果与理论评估相结合，我们揭示了其潜在机制，即有意引入的稀释外来Fe元素创造了更深的朗道能量阱并促进了极化的短程有序。我们开发的策略显著简化了非常规铁电体的设计，为探索新型和优质铁电材料提供了一条通用途径。
