标题： 层状铁电体在薄膜中的复兴 显示英文标题

标题： Revival of Layered Ferroelectrics in Thin Films

摘要： 层状钙钛矿是一类多功能的铁电材料，其结构各向异性体现在不寻常的静电特性中，从而产生卓越的铁电性能。 这些材料分为四个主要家族：Aurivillius、Carpy-Galy、Ruddlesden-Popper 和 Dion-Jacobson 相；每个家族通过将钙钛矿层与间隔层交替排列形成天然超晶格。 长期以来，这些材料被认为结构过于复杂，难以制备高质量的薄膜。 然而，沉积技术和先进表征的最新突破使得能够以原子精度稳定高质量的薄膜，揭示了各种非常规的铁电功能。 这些包括在没有临界厚度的情况下具有鲁棒的面内极化、带电畴壁和非平凡极化纹理的出现、对掺杂磁性离子和载流子的耐受性，以及可能外延集成到标准钙钛矿异质结构中的可能性。 本综述旨在统一当前关于层状铁电薄膜的制备和表征的知识，并呈现所有四个结构家族的研究成果，目的是突出它们的共同特征，尽管晶体结构和极化机制存在差异。 我们还讨论了有前景的研究方向，包括极性金属性、(改性)磁电性、剥离和软化学驱动的相变，旨在巩固该领域并鼓励进一步探索这些材料在基础研究和应用中的潜力。 显示英文摘要

摘要： Layered perovskites are a versatile class of ferroelectrics with their structural anisotropy reflected in unusual electrostatics that give rise to exceptional ferroelectric properties. These materials fall into four main families: Aurivillius, Carpy-Galy, Ruddlesden-Popper, and Dion-Jacobson phases; each forming natural superlattices by interleaving perovskite slabs with spacer layers. For a long time, these materials were considered too structurally complex to prepare as high-quality thin films. However, recent breakthroughs in deposition and advanced characterization have made it possible to stabilize high-quality films with atomic precision, uncovering a wide range of unconventional ferroelectric functionalities. These include robust in-plane polarization without a critical thickness, the emergence of charged domain walls and non-trivial polar textures, resilience to doping with magnetic ions and charge carriers, and possibility to epitaxially integrate them into standard perovskite heterostructures. This review aims to unify current knowledge on the fabrication and characterization of layered ferroelectric thin films, and to present research findings across all four structural families, with the goal of highlighting their common features despite differences in crystal structure and polarization mechanisms. We also discuss promising research directions, including polar metallicity, (alter-)magnetoelectricity, exfoliation, and soft-chemistry-driven phase transformations, with the goal of consolidating the field and encouraging further exploration of these materials for both fundamental studies and applications.