Decoupled Strain Response of Ferroic Properties in Multiferroic VOCl2 Monolayer

TL;DR

This study demonstrates that strain-engineering can independently tune magnetic and electric properties in 2D VOCl2 monolayers, enhancing their potential for nanoelectronic applications.

Contribution

It reveals that uniaxial tensile strain can selectively control magnetic order and electric polarization in 2D VOCl2, a novel multiferroic material.

Findings

4% tensile strain induces magnetic phase transition from AFM to FM

Strain along different axes independently tunes magnetism and polarization

Strain enhances Curie temperature and stability of the monolayer

Abstract

Two-dimensional (2D) magnetoelectric multiferroics are promising multifunctional materials for miniaturized logic and memory devices. Herein, we explore the effectiveness of strain-engineering for tuning the properties of a recently predicted 2D antiferromagnetic-ferroelectric, VOCl2 monolayer. Interestingly, we find that magnetic-ordering and electric polarization can be tuned independently using uniaxial tensile strain along different in-plane lattice vectors. A 4% tensile strain along lattice vector b induces a transition from an antiferromagnetic (AFM) ground state with an out-of-plane magnetization to a ferromagnetic (FM) ground state with in-plane magnetization. On the other hand, tensile strain along lattice vector a enhances spontaneous electric polarization, without affecting the magnetic ordering. The monolayers remain dynamically stable under tensile strain, which further helps to raise the Curie temperature of ferromagnetism, as well as ferroelectricity. Such a strain-tunable multiferroic material holds great promises for future generation nanoelectronic devices.