Ferroelectricity in strained Hf${}_2$CF${}_2$ monolayer

Abstract

Low dimensional ferroelectrics are highly desired for applications and full of exotic physics. Here a functionalized MXene Hf${}_2$CF${}_2$ monolayer is theoretically studied, which manifests a nonpolar to polar transition upon moderate biaxial compressive strain. Accompanying this structural transition, a metal-semiconductor transition occurs. The in-plane shift of unilateral fluorine layer leads to a polarization pointing out-of-plane. Such ferroelectricity is unconventional, similar to the recently-proposed interlayer-sliding ferroelectricity but not identical. Due to its specific hexapetalous potential energy profile, the possible ferroelectric switching paths and domain walls are nontrivial, which are mediated via the metallic paraelectric state. In this sense, the metallic walls can be manipulated by reshaping the ferroelectric domains.

7 pages, 6 figures

References in corpus (6)

• A tight-binding approach to uniaxial strain in graphene
• Origin of magnetoelectric behavior in BiFeO${}_3$
• Type-II multiferroic Hf${}_2$VC${}_2$F${}_2$ MXene monolayer with high transition temperature
• Two-Dimensional Hyperferroelectric Metals: a Different Route to Ferromagnetic-Ferroelectric Multiferroics
• Ferroic orders in two-dimensional transition/rare-earth metal halides
• Charge transfer and hybrid ferroelectricity in (YFeO${}_3$)${}_n$/(YTiO${}_3$)${}_n$ magnetic superlattices

Cited by in corpus (6)

• Direct observation of geometric and sliding ferroelectricity in an amphidynamic crystal
• Gadolinium halide monolayers: a fertile family of two-dimensional 4f magnets
• Large in-plane negative piezoelectricity and giant nonlinear optical susceptibility in elementary ferroelectric monolayers
• Stacking dependent ferroelectricity and antiferroelectricity in quasi-one-dimensional oxyhalides NbO$X_3$
• Ferroelectricity in oxygen-terminated 2D carbides of lanthanide elements
• Ferroelectricity induced by the absorption of water molecules on double helix SnIP