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arXiv · 2107.04956

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

Ziwen Wang·Ning Ding·Churen Gui·Shanshan Wang·Ming An·Shuai Dong
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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.

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Ziwen Wang, Ning Ding, Churen Gui, Shanshan Wang, Ming An, Shuai Dong. 2021-07-11. Ferroelectricity in strained Hf$_2$CF$_2$ monolayer. https://doi.org/10.1103/physrevmaterials.5.074408

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