Size‐Induced Ferroelectricity in Antiferroelectric Oxide Membranes

Abstract

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 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.

Stabilized Ferroelectric NaNbO3 Nanowires for Lead-Free Piezoelectric Nanocomposite Applications

“…These data imply that the SHG intensity along the X direction is presumably driven by a dominant susceptibility tensor element, while the intensity along the Y direction is driven by several susceptibility tensor elements of comparable magnitude. The full SHG tensorial analysis of these polar plots would provide the local orientation of the crystallographic axes at the single NW level and possibly reveal the local defects with distinct crystallographic orientations or the presence of AFE domains. , …”

“…The full SHG tensorial analysis of these polar plots would provide the local orientation of the crystallographic axes at the single NW level and possibly reveal the local defects with distinct crystallographic orientations or the presence of AFE domains. 51,52 ■…”

Low voltage–driven high-performance thermal switching in antiferroelectric PbZrO 3 thin films

“…Previous studies have demonstrated that P r of PZO films exhibits an increasing trend as the film thickness decreases, suggesting the coexistence of a metastable FE phase when the film is thin (<100 nm) ( 42 – 44 ). Thus, to mitigate the impact of the FE component we epitaxially grew high-quality PZO films with different thicknesses on SrRuO 3 (SRO) buffered SrTiO 3 (STO) substrates.…”

Development status of optical-electrical-magnetic high-flux coupling materials

“…On the other hand, from the perspective of symmetry, ferroelectricity must destroy spatial inversion symmetry, while ferromagnetism must destroy temporal inversion symmetry [54]. Therefore, magnetoelectric polyferism requires the inversion symmetry of time and space to be broken [55].…”