# Strain-tunable magnetic order and electronic structure in 2D CrAsS$_4$

## TL;DR

This study uses first-principles calculations to show how strain can switch the magnetic order and alter the electronic structure of single-layer CrAsS$_4$, offering insights for designing strain-controlled spintronic devices.

## Contribution

It reveals strain-induced magnetic phase transitions and electronic changes in 2D CrAsS$_4$, providing a new approach for strain-modulated spintronic applications.

## Key findings

- Strain can induce a transition from AFM to FM in CrAsS$_4$
- Band gap changes abruptly during magnetic phase transition
- Physical mechanism involves competition between exchange interactions

## Abstract

The effect of strain on the magnetic order and band structure of single-layer CrAsS$_4$ has been investigated by first-principles calculations based on density functional theory. We found that single-layer CrAsS$_4$ was an antiferromagnetic (AFM) semiconductor, and would have a phase transition from AFM state to ferromagnetic (FM) state by applying a uniaxial tensile strain of 2.99\% along the y-direction or compressive strain of 1.76\% along the x-direction. The underlying physical mechanism of strain-dependent magnetic stability was further elucidated as the result of the competition between the direct exchange and indirect superexchange interactions. Moreover, band gap exhibit a abrupt change along with phase transition of magnetic order. Our study provides an intuitional approach to design strain-modulated spintronic devices.