Transport, Magnetic and Vibrational Properties of Chemically Exfoliated Few Layer Graphene

Abstract

We study the vibrational, magnetic and transport properties of Few Layer Graphene (FLG) using Raman and electron spin resonance spectroscopy and microwave conductivity measurements. FLG samples were produced using wet chemical exfoliation with different post-processing, namely ultrasound treatment, shear mixing, and magnetic stirring. Raman spectroscopy shows a low intensity D mode which attests a high sample quality. The G mode is present at $1580$ cm${}^{-1}$ as expected for graphene. The 2D mode consists of 2 components with varying intensities among the different samples. This is assigned to the presence of single and few layer graphene in the samples. ESR spectroscopy shows a main line in all types of materials with a width of about $1$ mT and and a $g$-factor in the range of $2.005-2.010$. Paramagnetic defect centers with a uniaxial $g$-factor anisotropy are identified, which shows that these are related to the local sp${}^2$ bonds of the material. All kinds of investigated FLGs have a temperature dependent resistance which is compatible with a small gap semiconductor. The difference in resistance is related to the different grain size of the samples.

References in corpus (11)

• Electric Field Effect in Atomically Thin Carbon Films
• The electronic properties of graphene
• The Raman Fingerprint of Graphene
• Substrate-induced band gap opening in epitaxial graphene
• Control and Characterization of Individual Grains and Grain Boundaries in Graphene Grown by Chemical Vapor Deposition
• Chemistry with Graphene and Graphene Oxide - Challenges for Synthetic Chemists
• Few layer graphene on SiC, pyrolitic graphite and graphene: a Raman scattering study
• On the Nature of Defects in Liquid-Phase Exfoliated Graphene
• Statistical-Raman-Microscopy and Atomic-Force-Microscopy on Heterogeneous Graphene Obtained after Reduction of Graphene Oxide
• Reductive Arylation of Graphene: Insights into a Reversible Carbon Allotrope Functionalization Reaction
• A broadband and high throughput single-monochromator Raman spectrometer; application for single-wall carbon nanotubes

Cited by in corpus (4)

• Incidence of multilayers in chemically exfoliated graphene
• Ultralong spin lifetime in light alkali atom doped graphene
• Electronic and magnetic properties of black phosphorus
• Tuning Conductivity and Spin Dynamics in Few-Layer Graphene via In Situ Potassium Exposure