Prediction of two-dimensional antiferromagnetic ferroelasticity in an AgF2 monolayer

Abstract

Two-dimensional multiferroics, simultaneously harboring antiferromagneticity and ferroelasticity, are essential and highly sought for miniaturized device applications, such as high-density data storage, but thus far they have rarely been explored. Herein, using first principles calculations, we identified two-dimensional antiferromagnetic ferroelasticity in an AgF₂ monolayer that is dynamically and thermally stable, and can be easily fabricated from its bulk. The AgF₂ monolayer is an antiferromagnetic semiconductor with large spin polarization, and with great structural distortion due to its intrinsic Jahn–Teller effect when thinning the AgF₂ down to a monolayer. Additionally, it features excellent ferroelasticity with high transition signal and a low switching barrier, rendering the room-temperature nonvolatile memory accessible. Such coexistence of antiferromagneticity and ferroelasticity is of great significance to the study of two-dimensional multiferroics and also renders the AgF₂ monolayer a promising platform for future multifunctional device applications.