Plasma modification of the electronic and magnetic properties of vertically aligned bi-/tri-layered graphene nanoflakes

Ray, Sekhar C.; Soin, Navneet; Pong, W. F.; Roy, Susanta Sinha; Strydom, A. M.; McLaughlin, James; Papakonstantinou, Pagona

doi:10.1039/c6ra14457h

Cited by 5 publications

(3 citation statements)

References 92 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This technique measures the weak but long-range magnetic interactions between a sample and a magnetized tip and, accordingly, monitors the magnetic response using the frequency and phase shift of the cantilever. 33,67 The lift-height mode utilized in our current and earlier works minimizes the influence of topography on the observed signal. Now, it is expected that, at higher nitrogen concentrations, defect formation along with the substitutional nitrogen in the graphene lattice can enhance the ferromagnetic ordering and consequently the saturation magnetization values.…”

Section: Resultsmentioning

confidence: 99%

“…The enhancement of the magnetic properties of the FLG:N(ECR) samples was further assessed in terms of the growth of magnetic domains using MFM imaging. This technique measures the weak but long-range magnetic interactions between a sample and a magnetized tip and, accordingly, monitors the magnetic response using the frequency and phase shift of the cantilever. , The lift-height mode utilized in our current and earlier works minimizes the influence of topography on the observed signal. Figure d–i shows the AFM topography, amplitude and phase signals for the pristine and FLG:N(ECR) samples, whereas Figure j–o shows the sample features in MFM mode.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Tuning the Electronic and Magnetic Properties of Nitrogen-Functionalized Few-Layered Graphene Nanoflakes

et al. 2017

Self Cite

View full text Add to dashboard Cite

In this work, we report on the modification of electronic and magnetic properties of few layered graphene (FLG) nanoflakes via nitrogen functionalisation carried out using radio frequency (rf-PECVD) and electron cyclotron resonance (ECR) plasma processes. Even though the rf-PECVD N2 treatment leads to higher Ndoping levels in the FLGs (4.06 at%) as compared to the ECR process (2.18 at.%), the ferromagnetic behaviour of ECR FLG(118.62 x 10 -4 emu/gm) was significantly higher than the rf-PECVD (0.39 x 10 -4 emu/gm) and pristine graphene (3.47 x 10 -4 emu/gm). While both plasma processes introduce electron donating N-atoms in the graphene structure, distinct dominant nitrogen bonding configurations (pyridinic, pyrrolic) were observed for each FLG type. While, the ECR plasma introduces more sp 2 type nitrogen moieties, the rf-PECVD process led to the formation of sp 3 coordinated nitrogen functionalities, as confirmed through Raman measurements. The samples further characterised using X -ray absorption near edge spectroscopy (XANES) and X-ray, ultraviolet photoelectron spectroscopies revealed an increased electronic density of states and a significantly higher concentration of pyrrolic groups in the rf-PECVD samples. Due to the formation of reactive edge structures and pyridinic nitrogen moieties, the ECR functionalised FLGs expressed highest saturation magnetisation behaviour with the lowest field hysteretic features. In comparison, the rf-PECVD samples, displayed the lowest saturation magnetisation owing to the disappearance of magnetic edge states and formation of stable non-radical type defects in the pyrrole type structures. Our experimental results thus provide new evidence to control the magnetic and electronic properties of few layered graphene nanoflakes via control of the plasma-processing route.• INTRODUCTIONIntrinsic magnetism observed in materials without d-or f-electrons has attracted much interest, especially for carbon-based materials and in particular, graphene. There has been a long-standing interest in the development of ferromagnetic graphene for realizing its applications into spintronic devices via the combination of spin and charge. [1][2][3][4] The introduction of magnetic response in graphene via the introduction of edges, vacancy defects or adsorbed atoms has been investigated using both theoretical and experimental means. [1][2][3][4][5][6][7][8][9][10][11][12][13] Various theoretical studies. [3][4][5][6][7][8][9][10] have suggested that zigzag edges or point defects in graphene as the spin units should 3 carry magnetic moment with possible long-range order coupling. This coupling itself can be ferromagnetic or antiferromagnetic, depending on whether the zigzag edges or defects correspond to the same or to different hexagonal sub-lattice of the graphene lattice, respectively. At present, the intrinsic magnetic properties of finite sized graphene sheet are far from being understood, given that the magnetic signal from a finite sized graphene sheet is too weak to be detected by macr...

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Tuning the Electronic and Magnetic Properties of Nitrogen-Functionalized Few-Layered Graphene Nanoflakes

et al. 2017

Self Cite

View full text Add to dashboard Cite

show abstract

“…[ 75 ] The vertically aligned bi‐/trilayered graphene nanoflakes functionalized with hydrogen/nitrogen/silicon species exhibiting ferromagnetic nature due to defects in graphene sheets. [ 92 ] The saturation magnetization of graphene is successfully enhanced by plasma‐based‐hydrogenation and nitrogenation reactions. In nitrogenation, due to the formation of a graphitic like extra π‐electron, the Fermi level shifted upwards, which improved the magnetic coupling between magnetic moments.…”

Section: Properties Of Vertically Aligned 2d Materials and Its Hetero...mentioning

confidence: 99%

Vertically Aligned Graphene‐Analogous Low‐Dimensional Materials: A Review on Emerging Trends, Recent Developments, and Future Perspectives

Shinde

Samal

Rout

2022

Adv Materials Inter

View full text Add to dashboard Cite

2D materials currently includes graphene, transition metal dichalcogenides (TMDs), hexagonal boron nitride (h-BN), 2D carbides/nitrides (MXenes), monoelemental Xenes, and perovskites. [2][3][4][5][6] These families opened new horizons for advanced applications since they have unusual electronic, mechanical, and optical properties. Though these materials have layered structures, yet their diversity in properties highly depends on their composition and phases.Graphene owns interesting properties like large surface area, dangling bond-free surface, high carrier mobility, high optical absorption coefficient, high Young's modulus, and high thermal conductivity. [7] However, the zero bandgap and semimetal properties of graphene limit its application in switching devices. h-BN attracted magnetized attention due to its superb chemical stability and intrinsic insulation. [8] As one of the most studied families, TMDs offer diversity in compositions, and phases, which exhibit many technologically interesting properties. [9][10][11] Among TMDs, MoS 2 is the most examined and well-explored material due to its robustness and semiconducting properties. TMDs offer a unique combination of atomic-scale thickness, strong spin-orbit coupling, sizeable bandgap, and favorable optoelectronic properties for numerous applications. [12] MXenes represent a large family of 2D materials whose several structures were predicted theoretically, while several of them have been realized experimentally also such as Ti

show abstract

Functionalization of Graphene—A Critical Overview of its Improved Physical, Chemical and Electrochemical Properties

Singh

Nalajala

Kar

et al. 2019

Carbon Nanostructures

View full text Add to dashboard Cite

Plasma modification of the electronic and magnetic properties of vertically aligned bi-/tri-layered graphene nanoflakes

Cited by 5 publications

References 92 publications

Tuning the Electronic and Magnetic Properties of Nitrogen-Functionalized Few-Layered Graphene Nanoflakes

Tuning the Electronic and Magnetic Properties of Nitrogen-Functionalized Few-Layered Graphene Nanoflakes

Vertically Aligned Graphene‐Analogous Low‐Dimensional Materials: A Review on Emerging Trends, Recent Developments, and Future Perspectives

Functionalization of Graphene—A Critical Overview of its Improved Physical, Chemical and Electrochemical Properties

Contact Info

Product

Resources

About