Prediction of two-dimensional ferromagnetic ferroelectric VOF$_2$ monolayer

TL;DR

This paper predicts a novel two-dimensional VOF2 monolayer that exhibits both intrinsic ferroelectricity and ferromagnetism, making it a promising candidate for high-performance magnetoelectric devices.

Contribution

The study introduces a new 2D VOF2 monolayer with the largest in-plane ferroelectric polarization and a robust ferromagnetic ground state, unlike other similar materials.

Findings

VOF2 monolayer has the largest in-plane ferroelectric polarization among VOX2 materials.

VOF2 monolayer exhibits a stable ferromagnetic ground state.

Provides a promising candidate for 2D multiferroic materials with high magnetoelectric performance.

Abstract

Nowadays, designing and searching for materials with multiple functional characteristics are the key to achieving high-performance electronic devices. Among many candidates, two-dimensional multiferroic materials have great potential to be applied in highly-integrated magnetoelectric devices, such as high-density non-volatile memories. Here, we predict a two-dimensional material VOF2 monolayer to possess intrinsic ferroelectric and ferromagnetic properties. The VOF$_2$ monolayer own the largest in-plane ferroelectric polarization ($332$ pC/m) in the family of VO$X_2$ ($X$: halogen) oxyhalides. Different from other VO$X_2$ monolayers whose magnetic ground states are antiferromagnetic or noncollinear spiral textures, the VOF$_2$ monolayer owns a robust ferromagnetic ground state, which is rare but highly desirable. Our theoretical prediction provides a good candidate and starting point for the further pursuit of more two-dimensional multiferroic materials with high-performance magnetoelectricity.