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

SC Ray, N Soin, WF Pong, SS Roy, AM Strydom, JAD McLaughlin, P Papakonstantinou

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

Saturation magnetization (Ms) of pristine bi-/tri-layered graphene (denoted as – FLG) is enhanced by over four (4) and thirty-four (34) times to 13.94 10-4 and 118.62 10-4 emu/g, respectively, as compared to pristine FLGs (Ms of 3.47 10-4 emu/g), via plasma-based-hydrogenation (known as graphone) and nitrogenation (known as N-graphene) reactions, respectively. However, upon organo-silane treatment on FLG (known as siliphene), the saturation magnetization is reduced by over thirty (30) times to 0.11 10-4 emu/ g, as compared to pristine FLG. Synchrotron based X-ray absorption near edge structure spectroscopy measurements have been carried out to investigate the electronic structure and the underlying mechanism responsible for the variation of magnetic properties. For graphone, the free spin available via the conversion of the sp2 / sp3 hybridized structure and the possibility of unpaired electrons from induced defects are the likely mechanism for ferromagnetic ordering. During nitrogenation, the Fermi level of FLGs is shifted upwards due to the formation of a graphitic like extrap-electron that makes the structure electron-rich, thereby, enhancing the magnetic coupling between magnetic moments. On the other hand, during the formation of siliphene, substitution of the C-atom in FLG by a Si-atom occurs and relaxes out the graphene plane to form Si–C tetrahedral sp3-bonding with a non-magnetic atomic arrangement showing no spin polarization phenomena and thereby reducing the magnetization. Thus, plasma functionalization offers a simple yet facile route to control the magnetic properties of the graphene systems and has potential implications for spintronic applications.
LanguageEnglish
Pages70913-70924
JournalRSC Advances
Volume6
Early online date21 Jul 2016
DOIs
Publication statusPublished - 2016

Fingerprint

Graphite
Electronic properties
Magnetic properties
Plasmas
Saturation magnetization
Electrons
X ray absorption near edge structure spectroscopy
Silanes
Magnetic couplings
Atoms
Magnetoelectronics
Spin polarization
Magnetic moments
Fermi level
Synchrotrons
Hydrogenation
Electronic structure
Magnetization
Substitution reactions
Defects

Keywords

  • Plasma modification
  • graphene nanoflakes

Cite this

@article{d9eafa20b29842f49203232b4e1d4705,
title = "Plasma modification of the electronic and magnetic properties of vertically aligned bi-/tri-layeredgraphene nanoflakes",
abstract = "Saturation magnetization (Ms) of pristine bi-/tri-layered graphene (denoted as – FLG) is enhanced by over four (4) and thirty-four (34) times to 13.94 10-4 and 118.62 10-4 emu/g, respectively, as compared to pristine FLGs (Ms of 3.47 10-4 emu/g), via plasma-based-hydrogenation (known as graphone) and nitrogenation (known as N-graphene) reactions, respectively. However, upon organo-silane treatment on FLG (known as siliphene), the saturation magnetization is reduced by over thirty (30) times to 0.11 10-4 emu/ g, as compared to pristine FLG. Synchrotron based X-ray absorption near edge structure spectroscopy measurements have been carried out to investigate the electronic structure and the underlying mechanism responsible for the variation of magnetic properties. For graphone, the free spin available via the conversion of the sp2 / sp3 hybridized structure and the possibility of unpaired electrons from induced defects are the likely mechanism for ferromagnetic ordering. During nitrogenation, the Fermi level of FLGs is shifted upwards due to the formation of a graphitic like extrap-electron that makes the structure electron-rich, thereby, enhancing the magnetic coupling between magnetic moments. On the other hand, during the formation of siliphene, substitution of the C-atom in FLG by a Si-atom occurs and relaxes out the graphene plane to form Si–C tetrahedral sp3-bonding with a non-magnetic atomic arrangement showing no spin polarization phenomena and thereby reducing the magnetization. Thus, plasma functionalization offers a simple yet facile route to control the magnetic properties of the graphene systems and has potential implications for spintronic applications.",
keywords = "Plasma modification, graphene nanoflakes",
author = "SC Ray and N Soin and WF Pong and SS Roy and AM Strydom and JAD McLaughlin and P Papakonstantinou",
year = "2016",
doi = "10.1039/c6ra14457h",
language = "English",
volume = "6",
pages = "70913--70924",
journal = "RSC Advances",
issn = "2046-2069",
publisher = "Royal Society of Chemistry",

}

Plasma modification of the electronic and magnetic properties of vertically aligned bi-/tri-layeredgraphene nanoflakes. / Ray, SC; Soin, N; Pong, WF; Roy, SS; Strydom, AM; McLaughlin, JAD; Papakonstantinou, P.

In: RSC Advances, Vol. 6, 2016, p. 70913-70924.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Plasma modification of the electronic and magnetic properties of vertically aligned bi-/tri-layeredgraphene nanoflakes

AU - Ray, SC

AU - Soin, N

AU - Pong, WF

AU - Roy, SS

AU - Strydom, AM

AU - McLaughlin, JAD

AU - Papakonstantinou, P

PY - 2016

Y1 - 2016

N2 - Saturation magnetization (Ms) of pristine bi-/tri-layered graphene (denoted as – FLG) is enhanced by over four (4) and thirty-four (34) times to 13.94 10-4 and 118.62 10-4 emu/g, respectively, as compared to pristine FLGs (Ms of 3.47 10-4 emu/g), via plasma-based-hydrogenation (known as graphone) and nitrogenation (known as N-graphene) reactions, respectively. However, upon organo-silane treatment on FLG (known as siliphene), the saturation magnetization is reduced by over thirty (30) times to 0.11 10-4 emu/ g, as compared to pristine FLG. Synchrotron based X-ray absorption near edge structure spectroscopy measurements have been carried out to investigate the electronic structure and the underlying mechanism responsible for the variation of magnetic properties. For graphone, the free spin available via the conversion of the sp2 / sp3 hybridized structure and the possibility of unpaired electrons from induced defects are the likely mechanism for ferromagnetic ordering. During nitrogenation, the Fermi level of FLGs is shifted upwards due to the formation of a graphitic like extrap-electron that makes the structure electron-rich, thereby, enhancing the magnetic coupling between magnetic moments. On the other hand, during the formation of siliphene, substitution of the C-atom in FLG by a Si-atom occurs and relaxes out the graphene plane to form Si–C tetrahedral sp3-bonding with a non-magnetic atomic arrangement showing no spin polarization phenomena and thereby reducing the magnetization. Thus, plasma functionalization offers a simple yet facile route to control the magnetic properties of the graphene systems and has potential implications for spintronic applications.

AB - Saturation magnetization (Ms) of pristine bi-/tri-layered graphene (denoted as – FLG) is enhanced by over four (4) and thirty-four (34) times to 13.94 10-4 and 118.62 10-4 emu/g, respectively, as compared to pristine FLGs (Ms of 3.47 10-4 emu/g), via plasma-based-hydrogenation (known as graphone) and nitrogenation (known as N-graphene) reactions, respectively. However, upon organo-silane treatment on FLG (known as siliphene), the saturation magnetization is reduced by over thirty (30) times to 0.11 10-4 emu/ g, as compared to pristine FLG. Synchrotron based X-ray absorption near edge structure spectroscopy measurements have been carried out to investigate the electronic structure and the underlying mechanism responsible for the variation of magnetic properties. For graphone, the free spin available via the conversion of the sp2 / sp3 hybridized structure and the possibility of unpaired electrons from induced defects are the likely mechanism for ferromagnetic ordering. During nitrogenation, the Fermi level of FLGs is shifted upwards due to the formation of a graphitic like extrap-electron that makes the structure electron-rich, thereby, enhancing the magnetic coupling between magnetic moments. On the other hand, during the formation of siliphene, substitution of the C-atom in FLG by a Si-atom occurs and relaxes out the graphene plane to form Si–C tetrahedral sp3-bonding with a non-magnetic atomic arrangement showing no spin polarization phenomena and thereby reducing the magnetization. Thus, plasma functionalization offers a simple yet facile route to control the magnetic properties of the graphene systems and has potential implications for spintronic applications.

KW - Plasma modification

KW - graphene nanoflakes

U2 - 10.1039/c6ra14457h

DO - 10.1039/c6ra14457h

M3 - Article

VL - 6

SP - 70913

EP - 70924

JO - RSC Advances

T2 - RSC Advances

JF - RSC Advances

SN - 2046-2069

ER -