Vacancy mediated magnetization and healing of a graphene monolayer
arXiv:1903.04180 · doi:10.1103/PhysRevB.99.125125
Abstract
Vacancy-induced magnetization of a graphene layer is investigated by means of a first principle DFT method. Calculations of the formation energy and the magnetization by creating the different number of vacancies in a supercell show that a clustering with big number of vacancies in the cluster is rather favorable than that of isolated vacancies, homogeneously distributed in the layer. The magnetic moment of a cluster with big number of vacancies is shown to be not proportional with the vacancy concentration, which is in good agreement with the recent experimental results. Our studies support the idea that although the vacancies in a graphene create a magnetic moment, they do not produce a magnetic ordering. It is shown that although the Lieb's rule for the magnetization in a hexagonal structure violates, two-vacancies, including a di-vacancy, in the supercell generate quasi-localized state when they belong to the different sublattices, and instead two-vacancies generate an extended state when they belong to the same sublattices. Analytical investigation of the dynamics of carbon atom- and vacancy-concentrations according to the non-linear continuity equations shows that the vacancies, produced by irradiation at the middle of a graphene layer, migrate to the edge of the sample resulting in a specific {\it 'segregation'} of the vacancy concentration and self-healing of the graphene.
arXiv comment12 pages, 5 figures, 3 Tables The paper is accepted to Physical Review B (March 2019)
References in corpus (20)
- Electric Field Effect in Atomically Thin Carbon Films
- Graphene: Status and Prospects
- Room-Temperature Quantum Hall Effect in Graphene
- Selfconsistent order-N density-functional calculations for very large systems
- Magnetism in Graphene Induced by Single-Atom Defects
- Emergence of magnetism in graphene materials and nanostructures
- The missing atom as a source of carbon magnetism
- Spin-half paramagnetism in graphene induced by point defects
- Room-temperature ferromagnetism in graphite driven by 2D networks of point defects
- Disorder Induced Localized States in Graphene
- Modeling disorder in graphene
- Limits on intrinsic magnetism in graphene
- Dual origin of defect magnetism in graphene and its reversible switching by molecular doping
- Graphene re-knits its holes
- Tuning the electronic structure of graphene by ion irradiation
- Direct Experimental Evidence of Metal-Mediated Etching of Suspended Graphene
- Self healing of vacancy defects in single layer graphene and silicene
- A critical analysis of vacancy-induced magnetism in mono and bilayer graphene
- Non-invasive transmission electron microscopy of vacancy defects in graphene produced by ion irradiation
- Graphene healing mechanisms: A theoretical investigation