Efe Ipek, Vogel Alexander, Huxter William S, Gradauskaite Elzbieta, Gaponenko Iaroslav, Paruch Patrycja, Degen Christian L, Rossell Marta D, Fiebig Manfred, Trassin Morgan
Department of Materials, ETH Zurich, Zurich, Switzerland.
Electron Microscopy Center, Empa, Dubendorf, Switzerland.
Nat Commun. 2025 Jul 3;16(1):6131. doi: 10.1038/s41467-025-60176-8.
Nanoscale electrostatic control of oxide interfaces enables physical phenomena and exotic functionalities beyond the realm of the bulk material. In technologically-relevant ferroelectric thin films, the interface-mediated polarization control is usually exerted by engineering the depolarizing field. Here, in contrast, we introduce polarizing surfaces and lattice chemistry engineering as an alternative strategy. Specifically, we engineer the electric-dipole ordering in ferroelectric oxide heterostructures by exploiting the charged sheets of the layered Aurivillius model system. By tracking in-situ the formation of the Aurivillius charged BiO sheets, we reveal their polarizing effect leading to the characteristic Aurivillius out-of-plane antipolar ordering. Next, we use the polarizing BiO stacking as a versatile electrostatic environment to create new electric dipole configurations. We insert multiferroic BiFeO into the Aurivillius framework to stabilize a ferrielectric-like non-collinear electric-dipole order in the final heterostructure while maintaining the antiferromagnetic order of BiFeO. We thus demonstrate that engineering the lattice chemistry stabilizes unconventional ferroic orderings at the nanoscale, a strategy that may be expanded beyond the realm of electrically ordered materials.
对氧化物界面进行纳米级静电控制能够实现超越块体材料范畴的物理现象和奇异功能。在与技术相关的铁电薄膜中，界面介导的极化控制通常是通过设计退极化场来实现的。相比之下，在这里我们引入极化表面和晶格化学工程作为一种替代策略。具体而言，我们通过利用层状奥里维利乌斯模型体系的带电薄片，来设计铁电氧化物异质结构中的电偶极有序排列。通过原位跟踪奥里维利乌斯带电BiO薄片的形成过程，我们揭示了它们的极化效应，这种效应导致了典型的奥里维利乌斯面外反极有序排列。接下来，我们将极化BiO堆叠用作通用的静电环境，以创建新的电偶极构型。我们将多铁性BiFeO插入奥里维利乌斯框架中，以在最终的异质结构中稳定类似铁电体的非共线电偶极有序排列，同时保持BiFeO的反铁磁有序排列。因此，我们证明了通过设计晶格化学能够在纳米尺度上稳定非常规的铁性有序排列，这一策略可能会扩展到电有序材料领域之外。
