# Magnetic states of linear defects in graphene monolayers: effects of strain and interaction

## TL;DR

This study investigates how strain and defect interactions influence magnetic states in graphene with 558 linear defects, revealing that uniaxial tensile strains can promote magnetism by modifying electronic states and Fermi level positioning.

## Contribution

It demonstrates that uniaxial tensile strains can be used to tune magnetic states in graphene defects, highlighting the interplay between strain, defect interaction, and electronic structure.

## Key findings

- Uniaxial tensile strains enhance defect state DOS and Fermi level alignment, promoting magnetism.
- Perpendicular strain increases DOS but detunes Fermi level, inhibiting magnetism.
- Biaxial strain effects depend on the relative magnitude of strain components.

## Abstract

The combined effects of defect-defect interaction and of uniaxial or biaxial strains of up to 10\% on the development of magnetic states on the defect-core-localized quasi-one-dimensional electronic states generated by the so-called 558 linear extended defect in graphene monolayers are investigated by means of {\it ab initio} calculations. Results are analyzed on the basis of the heuristics of the Stoner criterion. We find that conditions for the emergence of magnetic states on the 558 defect can be tuned by uniaxial tensile parallel strains (along the defect direction) at both limits of isolated and interacting 558 defects. Parallel strains are shown to lead to two cooperative effects that favor the emergence of itinerant magnetism: enhancement of the DOS of the resonant defect states in the region of the Fermi level and tuning of the Fermi level to the maximum of the related DOS peak. A perpendicular strain is likewise shown to enhance the DOS of the defect states, but it also effects a detunig of the Fermi level that shifts away from the maximum of the DOS of the defect states, which inhibts the emergence of magnetic states. As a result, under biaxial strains the stabilization of a magnetic state depends on the relative magnitudes of the two components of strain.