Effect of intercalation and exfoliation on positron annihilation lifetimes in graphites

Adonkin, V. T.; Gorelov, B. M.; Dyakin, V. V.; Karpov, I.I.; Prikhod’ko, G. P.

doi:10.1016/0022-3697(94)90171-6

Cited by 2 publications

(1 citation statement)

References 8 publications

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“…12 The gamma rays resulting from electron-positron annihilation experience Doppler shift due to the momentum of the electron, and hence the 511 keV gamma ray spectra, recorded using a high purity Ge detector, suffer from broadening and the lineshape of the spectrum represents the electron momentum distribution in the material. 12 Although PAS has been employed to study different forms of carbon earlier, 10,13,14 to the best of our knowledge, defect evolution in the GO-PANI composite as a function of process parameters remains unexplored. Here we report on the positron lifetime and coincidence Doppler broadening studies (CDBS) of the GO-PANI composite highlighting the effects of the synthesis conditions following the process described in ref.…”

Section: Introductionmentioning

confidence: 99%

Effects of process parameters on the defects in graphene oxide–polyaniline composites investigated by positron annihilation spectroscopy

Rana

Nambissan

Malik

et al. 2014

Phys. Chem. Chem. Phys.

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Graphene oxide (GO)-polyaniline (PANI) composites were prepared with different relative abundance of PANI and GO by in situ polymerization of aniline in the presence of GO and ammonium persulphate at different temperatures. In the process, GO also got reduced to graphene. Positron lifetimes and coincidence Doppler broadening of the electron-positron annihilation gamma ray spectra originating from the composite samples were measured and the results are reported. The positron lifetimes indicated the presence of very large size defects in the form of vacancy clusters within the samples. Another interesting observation was the increase of relative intensity of the defect specific positron lifetime component when an increase in relative abundance of PANI led to increased reduction of GO to graphene. The reduction also shrank the volume occupied by GO and the free volume thereby released added to the overall defect concentration, resulting in a simultaneous increase of the intensity of the positron lifetime component. The variation of the positron lifetime and its intensity with the synthesis temperature suggested an optimum temperature suitable for the process. The above observations are corroborated by other experimental investigations like electron microscopy, X-ray diffraction and electrical conductivity.

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Section: Introductionmentioning

confidence: 99%

Effects of process parameters on the defects in graphene oxide–polyaniline composites investigated by positron annihilation spectroscopy

Rana

Nambissan

Malik

et al. 2014

Phys. Chem. Chem. Phys.

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Surface Plasmon Resonance-Based Sensor Modeling

Meshginqalam

Ahmadi

Tousi³

et al. 2017

Handbook of Research on Nanoelectronic Sensor Modeling and Applications

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Exceptional optical and electrical characteristics of graphene based materials attract significant interest of the researchers to develop sensing center of surface Plasmon resonance (SPR) based sensors by graphene application. On the other hand refractive index calculation of graphene based structures is necessary for SPR sensor analysis. In this chapter first of all a new method for refractive index investigation of some graphene based structures are introduced and then the effect of carrier density variant in the form of conductance gradient on graphene based SPR sensor response is modeled. The molecular properties such as electro-negativity, molecular mass, effective group number and effective outer shell factor of the molecule are engaged. In addition each factor effect in the cumulative carrier variation is explored analytically. The refractive index shift equation based on these factors is defined and related coefficients are proposed. Finally a semi-empirical model for interpretation of changes in SPR curve is suggested and tested for some organic molecules.

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Effect of intercalation and exfoliation on positron annihilation lifetimes in graphites

Cited by 2 publications

References 8 publications

Effects of process parameters on the defects in graphene oxide–polyaniline composites investigated by positron annihilation spectroscopy

Effects of process parameters on the defects in graphene oxide–polyaniline composites investigated by positron annihilation spectroscopy

Surface Plasmon Resonance-Based Sensor Modeling

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