Magneto-optical Kerr effect and magnetoelasticity in weak ferromagnetic RuF$_4$ monolayer

TL;DR

This study uses relativistic density functional theory to explore the magnetic, magneto-optical, and magnetoelastic properties of monolayer RuF$_4$, revealing weak ferromagnetism, strong Kerr effect, and strain-induced spin rotation, with implications for 2D magnetic devices.

Contribution

It uncovers the magnetic order and magneto-optical/magnetoelastic properties of monolayer RuF$_4$, highlighting its potential for 2D magnetic applications.

Findings

Weak ferromagnetism due to Dzyaloshinskii-Moriya interaction

Prominent magneto-optical Kerr effect observed

Strain induces ferroelastic switching and spin rotation

Abstract

Considerable research interest has been attracted to noncollinear magnetic structures for their intriguing physics and promising applications. In this work, based on relativistic density functional theory, we reveal the interesting magnetic order and relevant properties in monolayer RuF$_4$, which can be exfoliated from its bulk phase. Although the spins on Ru ions are almost antiferromagnetically aligned between nearest-neighbors, weak ferromagnetism is generated because of the antisymmetric Dzyaloshinskii-Moriya interaction as well as the single-ion anisotropy. A prominent magneto-optical Kerr effect can be observed for this antiferromagnet, similar to those of regular strong ferromagnets. In addition, a uniaxial strain can induce a ferroelastic switching together with the in-plane rotation of spin direction, giving rise to a strong intrinsic magnetoelasticity. Our work not only suggests an alternative direction for two-dimensional magnetic materials, but also provides hints to future devices based on antiferromagnetic magnetoelastic or magneto-optical materials.