Ruijuan Xu1,Kevin Crust2,Varun Harbola3,Remi Arras4,Kinnary Patel5,Sergey Prosandeev5,Yu-Tsun Shao6,Piush Behera7,Lucas Caretta8,Woo Jin Kim2,Aarushi Khandelwal2,Megha Acharya7,Yin Liu1,Archana Raja9,Lane Martin7,Hua Zhou10,Ramamoorthy Ramesh11,David Muller12,Laurent Bellaiche5,Harold Hwang2
North Carolina State University1,Stanford University2,Max Planck Institute for Solid State Research3,Universite de Toulouse4,University of Arkansas, Fayetteville5,University of Southern California6,University of California, Berkeley7,Brown University8,Lawrence Berkeley National Laboratory9,Argonne National Laboratory10,Rice University11,Cornell University12
Ruijuan Xu1,Kevin Crust2,Varun Harbola3,Remi Arras4,Kinnary Patel5,Sergey Prosandeev5,Yu-Tsun Shao6,Piush Behera7,Lucas Caretta8,Woo Jin Kim2,Aarushi Khandelwal2,Megha Acharya7,Yin Liu1,Archana Raja9,Lane Martin7,Hua Zhou10,Ramamoorthy Ramesh11,David Muller12,Laurent Bellaiche5,Harold Hwang2
North Carolina State University1,Stanford University2,Max Planck Institute for Solid State Research3,Universite de Toulouse4,University of Arkansas, Fayetteville5,University of Southern California6,University of California, Berkeley7,Brown University8,Lawrence Berkeley National Laboratory9,Argonne National Laboratory10,Rice University11,Cornell University12
Despite 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 would provide key information for optimizing device performances at small scales. In this presentation, I will introduce our recent study about the fundamental intrinsic size dependence of antiferroelectricity in lead-free NaNbO3 freestanding membranes [1]. Via a wide range of experimental and theoretical approaches, we probe an intriguing antiferroelectric-to-ferroelectric transition upon reducing membrane thickness. 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, we show that the antiferroelectric and ferroelectric orders are electrically switchable. Such a structural evolution also drives a non-monotonic thickness dependence of Young’s modulus. We further reveal the observed transition is driven by the structural distortion arising from the membrane surface. Our 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.<br/><br/>[1] R. Xu et al. Advanced Materials 35, 2370121 (2023)