Revival of Layered Ferroelectrics in Thin Films

Abstract

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.

Literature review, 37 pages, 14 figures

References in corpus (21)

• Altermagnetism: spin-momentum locked phase protected by non-relativistic symmetries
• Experimental demonstration of hybrid improper ferroelectricity and presence of abundant charged walls in (Ca,Sr)${}_3$Ti${}_2$O${}_7$ crystals
• Oxide spintronics
• Defeating depolarizing fields with artificial flux closure in ultrathin ferroelectrics
• Topotactic Transition: A Promising Opportunity for Creating New Oxides
• Polar Metals Taxonomy for Materials Classification and Discovery
• Electrical Detection of Ferroelectric-like Metals through Nonlinear Hall Effect
• On the happiness of ferroelectric surfaces and its role in water dissociation: the example of bismuth ferrite
• Ferroelectricity in the Dion-Jacobson CsBiNb${}_2$O${}_7$ from first principles
• Free carrier induced ferroelectricity in layered perovskites
• A switchable two-dimensional electron gas based on ferroelectric Ca:SrTiO${}_3$
• Growth and atomically resolved polarization mapping of ferroelectric $B{i}_{2}W{O}_6$ thin film
• PbTi1-xPdxO3: A New Room-temperature Magnetoelectric Multiferroic Device Material
• Ferroelectricity of Dion-Jacobson layered perovskites CsNdNb${}_2$O${}_7$ and RbNdNb${}_2$O${}_7$
• Deterministic influence of substrate-induced oxygen vacancy diffusion on $B{i}_{2}W{O}_6$ thin film growth
• A three-order-parameter bistable magnetoelectric multiferroic metal
• Negative piezoelectricity in quasi-two/one-dimensional ferroelectrics
• Perspective on 2D perovskite ferroelectrics and multiferroics
• Polarization boost and ferroelectricity down to one unit cell in layered Carpy-Galy La${}_2$Ti${}_2$O${}_7$ thin films
• Magnetoelectric phase control at domain-wall-like epitaxial oxide multilayers
• Local structure and its implications for the relaxor ferroelectric Cd${}_2$Nb${}_2$O${}_7$