Strain-induced phase transition in CrI$_{3}$ bilayers

TL;DR

This study investigates how applying strain to CrI₃ bilayers can induce a phase transition between ferromagnetic and antiferromagnetic states, revealing strain as an effective tuning parameter for magnetic properties.

Contribution

It provides a detailed analysis of strain effects on magnetic phases, anisotropy, exchange coupling, and Curie temperature in CrI₃ bilayers, highlighting strain as a control mechanism.

Findings

Tensile strain stabilizes antiferromagnetic phase.

Compressive strain induces ferromagnetism.

Strain affects magnetic anisotropy and Curie temperature.

Abstract

A monolayer of CrI$_3$ is a two-dimensional crystal that in its equilibrium configuration is a ferromagnetic semiconductor, however, two coupled layers can be ferromagnetic or antiferromagnetic depending on the stacking. We study the magnetic phase diagram upon the strain of the antiferromagnetically coupled bilayer with C2/m symmetry. We found that strain may be an efficient tool to tune the magnetic phase of the structure. A tensile strain stabilizes the antiferromagnetic phase, while a compressive strain turns the system ferromagnetic. We understood that behavior by looking at the relative displacement between layers due to the strain. We also study the evolution of the magnetic anisotropy, the magnetic exchange coupling between Cr atoms, and how the Curie temperature is affected by the strain.