Stacking dependent ferroelectricity and antiferroelectricity in quasi-one-dimensional oxyhalides NbO$X_3$

TL;DR

This study uses first-principles calculations to explore stacking modes and polar properties of quasi-one-dimensional NbO$X_3$ oxyhalides, revealing diverse ferroelectric and antiferroelectric phases with promising polarization and piezoelectric properties.

Contribution

It uncovers multiple stacking-induced ferroelectric and antiferroelectric phases in NbO$X_3$, highlighting their potential for applications and the coexistence of phases under different conditions.

Findings

Multiple ferroelectric and antiferroelectric phases identified.

Polarizations comparable to BaTiO$_3$ and piezoelectricity to ZnO.

Proximity of phase energies suggests multiphase coexistence.

Abstract

Low-dimensional ferroelectricity and polar materials have attracted considerable attentions for their fascinating physics and potential applications. Based on first-principles calculations, here we investigate the stacking modes and polar properties of a typical series of quasi-one-dimensional ferroelectrics: double-chain oxyhalides NbO$X_3$ ($X$=Cl, Br, I). The geometry of their double-chains allows both the interchain/intrachain permutation. Thus, different stacking modes of double-chains lead to a variety of ferroelectric and antiferroelectric phases in both the tetragonal and monoclinic crystals. The proximate energies of these phases may lead to multiphase coexistence in real materials, as well as the hydrostatic pressure driving structural phase transition. Their spontaneous polarizations and piezoelectricity of the ferroelectric phases are prominent, comparable to commercially used ferroelectric BaTiO$_3$ and piezoelectric ZnO, respectively. Our work demonstrates that the van der Waals NbO$X_3$ are promising materials for exploring quasi-one-dimensional ferroelectricity and antiferroelectricity.