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Magnetic behavioural change of silane exposed graphene nanoflakes

Ray, SC, Mishra, DK, Strydom, AM and Papakonstantinou, P (2015) Magnetic behavioural change of silane exposed graphene nanoflakes. JOURNAL OF APPLIED PHYSICS, 118 . 115302-5 pages. [Journal article]

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URL: http://aip.scitation.org/doi/10.1063/1.4930932

DOI: 10.1063/1.4930932

Abstract

The electronic structures and magnetic properties of graphene nanoflakes (GNFs) exposed to anorgano-silane precursor [tetra-methyl-silane, Si(CH3)4] were studied using atomic force microscopy, electron field emission (EFE), x-ray photoelectron spectroscopy (XPS), and magnetization. The result of XPS indicates that silyl radical based strong covalent bonds were formed in GNFs, which induced local structural relaxations and enhanced sp3 hybridization. The EFE measurements show an increase in the turn-on electric field from 9.8V/lm for pure GNFs to 26.3 V/lm for GNFs:Si having highest Si/(SiþC) ratio (ffi0.35) that also suggests an enhancement of the non-metallic sp3 bonding in the GNFs matrix. Magnetic studies show that the saturation magnetization (Ms) is decreased from 172.5310-6 emu/g for pure GNFs to 13.00 10-6 emu/g for GNFs:Si with the highest Si/(SiþC) ratio 0.35, but on the other side, the coercivity (Hc) increases from 66 to 149Oe due to conversion of sp2 to sp3-hybridization along with the formation of SiC and Si-O bonding in GNFs. The decrease in saturation magnetization and increase in coercivity (Hc) in GNFs on Si-functionalization are another routes to tailor the magnetic properties of graphene materials for magnetic device applications.

Item Type:Journal article
Keywords:Silicon doped graphene nanoflakes, electron field emission, x-ray photoelectron spectroscopy (XPS), magnetization,
Faculties and Schools:Faculty of Computing & Engineering
Faculty of Computing & Engineering > School of Engineering
Research Institutes and Groups:Engineering Research Institute
Engineering Research Institute > Nanotechnology & Integrated BioEngineering Centre (NIBEC)
ID Code:36977
Deposited By: Professor Pagona Papakonstantinou
Deposited On:13 Mar 2017 13:46
Last Modified:17 Oct 2017 16:27

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