Xu, RuijuanCrust, Kevin J.Harbola, VarunArras, RémiPatel, Kinnary Y.Prosandeev, SergeyCao, HuiShao, Yu-TsunBehera, PiushCaretta, LucasKim, Woo JinKhandelwal, AarushiAcharya, MeghaWang, Melody M.Liu, YinBarnard, Edward S.Raja, ArchanaMartin, Lane W.Gu, X. WendyZhou, HuaRamesh, RamamoorthyMuller, David A.Bellaiche, LaurentHwang, Harold Y.2023-05-022023-05-022023Xu, Ruijuan, Crust, Kevin J., Harbola, Varun, et al.. "Size-Induced Ferroelectricity in Antiferroelectric Oxide Membranes." <i>Advanced Materials,</i> 35, no. 17 (2023) Wiley: https://doi.org/10.1002/adma.202210562.https://hdl.handle.net/1911/114862Despite extensive studies on size effects in ferroelectrics, how structures and properties evolve in antiferroelectrics with reduced dimensions still remains elusive. Given the enormous potential of utilizing antiferroelectrics for high-energy-density storage applications, understanding their size effects will provide key information for optimizing device performances at small scales. Here, the fundamental intrinsic size dependence of antiferroelectricity in lead-free NaNbO3 membranes is investigated. Via a wide range of experimental and theoretical approaches, an intriguing antiferroelectric-to-ferroelectric transition upon reducing membrane thickness is probed. This size effect leads to a ferroelectric single-phase below 40 nm, as well as a mixed-phase state with ferroelectric and antiferroelectric orders coexisting above this critical thickness. Furthermore, it is shown that the antiferroelectric and ferroelectric orders are electrically switchable. First-principle calculations further reveal that the observed transition is driven by the structural distortion arising from the membrane surface. This work provides direct experimental evidence for intrinsic size-driven scaling in antiferroelectrics and demonstrates enormous potential of utilizing size effects to drive emergent properties in environmentally benign lead-free oxides with the membrane platform.engThis is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.Journal article2023-Xuhttps://doi.org/10.1002/adma.202210562