Localization and nonlinear transport in single walled carbon nanotube fibers

Ксеневич, В. К.; Odzaev, V. B.; Martunas, Z.; Seliuta, D.; Valušis, Gintaras; Galibert, J.; Melnikov, Alexander; Wieck, A. D.; Novitski, David; Kozlov, Mikhail E.; Samuilov, Vladimir

doi:10.1063/1.2996036

Cited by 26 publications

(23 citation statements)

References 37 publications

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“…For both types of the samples the distance between contacts was much higher than the length of the separate nanotubes in the arrays, thus enhancing the probability to observe the localization effects. Investigation of transport in SWCNTs monolayers confirms the importance of intertube contacts between separate nanotubes in their assemblies (Ksenevich et al, 2006). The temperature dependence of the resistance R(T) of the SWCNTs arrays is shown in Fig.…”

Section: Electrical and Magnetotransport Properties Of Carbon Nanotubmentioning

confidence: 81%

Charge Transport in Carbon Nanotube Films and Fibers

Ксеневич¹,

Galibert²,

Samuilov³

2010

Carbon Nanotubes

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Section: Electrical and Magnetotransport Properties Of Carbon Nanotubmentioning

confidence: 81%

Charge Transport in Carbon Nanotube Films and Fibers

Ксеневич¹,

Galibert²,

Samuilov³

2010

Carbon Nanotubes

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“…Unlike materials where Mott VRH [143] or weak localization [70] are determined to be dominant conduction mechanisms, there is no well-defined theoretical description of the magnetoresistance behaviour of a material that conducts via FIT [72]. Experimental observations have been made of both positive and negative magnetoresistance in systems where FIT is determined to be the dominant conduction mechanism [138], [144].…”

Section: Magnetoresistance Model Fitsmentioning

confidence: 93%

“…Hopping conduction has been observed in magnetotransport measurements, but other mechanisms, such as thermally activated transport, have can been seen in these samples. Different mechanisms are dominant in different temperature intervals [72]. Another important transport mechanism found to dominate in optically transparent samples is Coulomb gap variable range hopping.…”

Section: Electrical Transport Properties Of Carbon Nanotubesmentioning

confidence: 99%

The electrical transport properties of nitrogen doped carbon microspheres

Wright

Marsicano

Keartland

et al. 2014

Materials Chemistry and Physics

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A suite of four samples of nitrogen doped carbon microspheres, each with a different level of nitrogen dopant, was synthesised in a horizontal chemical vapour deposition reaction. The samples were characterized using scanning electron microscopy, Raman spectroscopy and electron paramagnetic resonance spectroscopy. Scanning electron microscopy showed that microspheres were produced by the reaction. Raman spectroscopy confirmed the graphitic nature of the samples. Electron paramagnetic resonance spectroscopy determined that nitrogen was present in the graphitic lattice and was used as a non-destructive technique to measure the amount of substitutional nitrogen present in the samples. In order to perform electrical transport measurements an automated magneto-transport measurement station was developed in the laboratory. This transport station was computer controlled and contained all of the necessary hardware and software required to perform magneto-electrical transport measurements. Variable temperature electrical transport measurements were performed on all samples to determine their conductive properties. Resistance measurements showed that two of the samples were semiconductors while the other two samples displayed a transition to metallic behaviour at higher temperatures. This transition can be ascribed to the thermal desorption of nitrogen dopant. Models were fitted to the data and the semiconducting behaviour is best explained by a model of fluctuation induced tunnelling while the metallic behaviour is best explained by a quasi-1 dimensional metallic term based on electron-phonon interactions. The IV characteristics of two of the samples display increasing non-linearity of the current's voltage dependence with decreasing temperature. The other two samples exhibit this behaviour at lower temperatures while higher temperature IV data displays a current saturation with increasing voltage. The same models used to explain the resistance measurements can be used to explain the IV characteristics data extremely well. The magnetoresistance data taken with the direction of current flow orientated both parallel and perpendicular to the field, show a transition from negative to positive magnetoresistance with decreasing temperature. The results of these experiments are inconclusive, as a theoretical model of magnetoresistance in systems that conduct via fluctuation induced tunnelling is not well defined. A comparison between the resistance measurements of all four samples was made to determine the effect of nitrogen doping on the samples' ii Abstract electronic transport properties. The result of this comparison was indeterminate. This was due to samples with identical nitrogen dopant levels displaying vastly different conductive properties and indicates that very strict synthesis conditions need to be adhered to in order to ensure sample quality. Resistance measurements were rerun on the two samples that displayed purely semiconducting behaviour to investigate the possibility of atmospheric doping. It was foun...

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“…Negative perpendicular MR is experimentally observed in disordered systems [17][18][19][20][21][22][23] where the VRH [17][18][19][20] or FIT [24] mechanisms work. Nevertheless, a systematic calculation of the dependence of MR on magnetic field and temperature has been developed in the framework of VRH theory [14,20,25] even though it is qualitatively accepted also in the case of FIT [24].…”

Section: Magnetoresistance Measurementsmentioning

confidence: 99%

“…The condition r > w is, in fact, necessary if one assumes that interference or overlapping effects between wavefunctions related to neighbouring states are at the base of the considered theory. The curves in figure 5(c) are fits to the data following the VRH model [21] and valid at moderate electric fields:…”

Section: Current-voltage Characteristicsmentioning

confidence: 99%

Low temperature conductivity of carbon nanotube aggregates

Salvato

Lucci

Ottaviani

et al. 2011

J. Phys.: Condens. Matter

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We compare, over wide temperature ranges, the transport properties of single-wall carbon nanotubes arranged in the form of aligned arrays or in the form of fibres. The experimental data show that both the forms of aggregates present a crossover in the transport mechanism from three-dimensional hopping of the electrons between localized states at high temperature to fluctuation-induced tunnelling across potential barriers at low temperature. The role of the junctions formed between the bundles in the array and between the nanotubes inside the fibres is discussed on the basis of the experimental results.

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Localization and nonlinear transport in single walled carbon nanotube fibers

Cited by 26 publications

References 37 publications

Charge Transport in Carbon Nanotube Films and Fibers

Charge Transport in Carbon Nanotube Films and Fibers

The electrical transport properties of nitrogen doped carbon microspheres

Low temperature conductivity of carbon nanotube aggregates

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