Monovacancy-induced magnetism in graphene bilayers

TL;DR

This study uses density functional theory to examine how vacancies in graphene bilayers affect magnetic properties, revealing a reduction in magnetic moments due to interlayer charge transfer.

Contribution

It provides new insights into vacancy-induced magnetism in graphene bilayers and highlights the role of interlayer charge transfer in modulating magnetic moments.

Findings

Magnetic moments decrease by ~10% in bilayers compared to monolayers.

Interlayer charge transfer compensates for defect-induced magnetic moments.

Vacancy position influences the extent of magnetic moment reduction.

Abstract

Vacancy-induced magnetism in graphene bilayers is investigated using spin-polarized density functional theory calculations. One of two graphene layers has a monovacancy. Two atomic configurations for bilayers are considered with respect to the position of the monovacancy. We find that spin magnetic moments localized at the vacancy site decreases by ~10 % for our two configurations, compared with the graphene monolayer with a monovacancy. The reduction of the spin magnetic moment in the graphene bilayers is attributed to the interlayer charge transfer from the adjacent layer to the layer with the monovacancy, compensating for spin magnetic moments originating from quasilocalized defect state.