Vacancy spatial distribution causes different magnetism in graphene

Antonov, V.; Borisova, Dobrina; Proykova, Ana

doi:10.1002/qua.24078

Cited by 7 publications

(9 citation statements)

References 17 publications

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“…298 Moreover, it is considered that for SV, the total magnetic moment is the sum of the magnetic moment (1 m B ) localized at the s bands and a fractional value of the extended p bands. The magnitude of the magnetic moment is found to be sensitive to defect concentration, separation between vacancies, 299,303 the passivation of dangling s bonds and unpassivated s bonds. 301 DFT spin polarized calculations for a single vacancy showed that the presence of the vacancy produces a pentagon-like structure due to the formation of a weak covalent bond between two atoms surrounding the vacancy.…”

Section: Modulation Via Creation Of Vacancies and Its Applicationsmentioning

confidence: 98%

Modulating the electronic and magnetic properties of graphene

et al. 2017

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Graphene, an sp2 hybridized single sheet of carbon atoms organized in a honeycomb lattice, is a zero band gap semiconductor or semimetal. This emerging material has been the subject of recent intensive research due to the novelty of its structural, electronic, optical, mechanical, and magnetic properties. Due to these properties, graphene is a favorable material for the fabrication of electronic devices, transparent electrodes, spintronics devices, and a growing array of several other applications that explore the potential of this marvelous material. However, the lack of intrinsic band gap and nonmagnetic nature of graphene limit its practical applications in the widely expanding field of carbon-based devices. To take advantage of the hidden potential of this material, numerous techniques have been developed to tailor its electronic and magnetic properties. These methods include the mutual interaction between graphene layer and its substrate, doping with surface adatoms, substitutional doping, vacancy creation, and edges and strain manipulation. Herein, an overview of recently emerging innovative techniques adopted to tailor the electronic and magnetic properties of graphene is presented. The limitations, possible directions for future research and applications in diverse fields of these methods are also mentionedpublishersversionPeer reviewe

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Section: Modulation Via Creation Of Vacancies and Its Applicationsmentioning

confidence: 98%

Modulating the electronic and magnetic properties of graphene

et al. 2017

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“…Researchers are currently very keen in trying to add magnetism to the several extraordinary capabilities of graphene using various strategies. − The origin of the magnetism induced by the presence of lattice defects has been largely debated by both the experimental − and computational − materials science communities during the past few years. Carbon monovacancy has been proposed as the candidate defect carrying a magnetic moment.…”

Section: Introductionmentioning

confidence: 99%

“…From the electronic structure and spin properties point of view, the theoretical investigations of the C monovacancy followed one another for the past decade, − first indicating a nonmagnetic ground state and then pointing to a magnetic one with computed magnetic moments ranging from 1 to 2 μ B , depending on the computational method and setup of calculations. As Wang et al pointed out before, this widely spread range of values is confusing and does not favor the rationalization of experimental findings that are not fully coherent, either.…”

Section: Introductionmentioning

confidence: 99%

“…The first view considers that, with increasing graphene model size and lowering of the vacancy concentration, the magnetization deriving from the dangling bond in the σ network is maintained as a very local atomic state, while the π magnetization is quenched as a consequence of a half electron transfer from the vπ α band to the vπ β band, which become perfectly degenerate at the infinite limit. Oppositely, the second view ,, proposes an increasing occupation of the vπ α band at the expenses of the vπ β with increasing graphene size, leading to a complete filling at the limit of an isolated C monovacancy.…”

Section: Introductionmentioning

confidence: 99%

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π Magnetism of Carbon Monovacancy in Graphene by Hybrid Density Functional Calculations

et al. 2017

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Understanding magnetism in defective graphene is paramount to improve and broaden its technological applications. A single vacancy in graphene is expected to lead to a magnetic moment with both a σ (1 μB) and a π (1 μB) component. Theoretical calculations based on standard LDA or GGA functional on periodic systems report a partial quenching of the π magnetization (0.5 μB) due to the crossing of two spin split bands at the Fermi level. In contrast, STS experiments (Phys. Rev. Lett.2016117166801) have recently proved the existence of two defect spin states that are separated in energy by 20–60 meV. In this work, we show that self-interaction corrected hybrid functional methods (B3LYP-D*) are capable of correctly reproducing this finite energy gap and, consequently, provide a π magnetization of 1 μB. The crucial role played by the exact exchange is highlighted by comparison with PBE-D2 results and by the magnetic moment dependence with the exact exchange portion in the functional used. The ground state ferromagnetic planar solution is compared to the antiferromagnetic and to the diamagnetic ones, which present an out-of-plane distortion. Periodic models are then compared to graphene nanoflakes of increasing size (up to C383H48). For large models, the triplet spin configuration (total magnetization 2 μB) is the most stable, independently of the functional used, which further corroborates the conclusions of this work and puts an end to the long-debated issue of the magnetic properties of an isolated C monovacancy in graphene.

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“…1–4 In particular, in recent years, with the rapid development of information technology, there has been growing interest in “magnetic” graphene and other atom-thick 2D materials with magnetic features due to their promising potential in flexible spintronic devices. 5–7 Although pristine graphene is diamagnetic in nature, magnetism in graphene or graphene derivatives can be induced by the introduction of defects into the lattice, doping of the graphene lattice with heteroatoms, such as nitrogen and boron, and engineering of edges. 2,5,8,9 Up to now, intriguing magnetic behavior has been observed in graphene analogues and related 2D materials such as transition metal dichalcogenides, phosphorene, MXenes, hexagonal boron nitride, and other organic compounds.…”

Section: Introductionmentioning

confidence: 99%