Electron transport in carbynes modified under high pressure

Demishev, S. V.; Pronin, A. A.; Ġlushkov, V. V.; Sluchanko, N. E.; Samarin, N. A.; Kondrin, M. V.; Lyapin, A. G.; Бражкин, В. В.; Varfolomeeva, T. D.; Попова, С. В.

doi:10.1134/1.1637704

Cited by 12 publications

(6 citation statements)

References 10 publications

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“…In this case, the values of α and T 0 in each group weakly depended on the CB concentration, and it was not specified what exactly is the difference between these two groups, and the causes of the correlation were 3 Another carbon system, namely, so-called carbynes, should be mentioned here; they are supposed to consist of chains of carbon atoms with the sp bonds. Hopping conductivity with α = 1/2, 1/3, and 1/4 is observed in carbyne samples depending on the synthesis temperature, and the case of α = 1/2 is explained by a one-dimensional character of hopping transport rather than by the presence of a Coulomb gap (see [43] and Refs. therein).…”

Section: Resultsmentioning

confidence: 99%

Activated hopping transport in nematic conducting aerogel at low temperatures

Tsebro,

Nikolaev,

Lugansky

et al. 2022

Preprint

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The transport properties of nematic aerogels, which consist of highly oriented Al2O3•SiO2 nanofibers coated with a graphene shell with a large number of defects, are studied. The temperature dependences of the electrical resistivity in the range of 9-40 K strictly follow the formula derived to describe the variable range hopping (VRH) conductivity, in which exponent α changes from 0.4 to 0.9 when the number of layers in the graphene shell decreases from 4-6 to 1-2. The dependence of α on the shell thickness can be explained by a simultaneous change in the dimensionality of hopping transport and the character of the energy dependence of the density of localized states near the Fermi level. The fact that α approaches unity at the minimum graphene shell thickness indicates a gradual transition from VRH transport to nearest neighbor hopping (NNH) transport. The magnetoresistance measured at T = 4.2 K is negative, increases significantly with decreasing graphene shell thickness, and is approximated by a formula for the case of weak localization with a good accuracy. The phase coherence lengths are in a reasonable relation with the graphene grain sizes. The conducting aerogels under study complement the well-known set of materials that exhibit hopping electron transport at low temperatures, which is characteristic of media with strong carrier localization, and also a negative magnetoresistance, which usually manifests itself under weak localization conditions.

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Section: Resultsmentioning

confidence: 99%

Activated hopping transport in nematic conducting aerogel at low temperatures

Tsebro,

Nikolaev,

Lugansky

et al. 2022

Preprint

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“…Another generic source of PMR is related to the effects of wave function shrinkage in the magnetic field. It usually dominates at the low temperatures in strongly disordered systems such as amorphous GaSb [20] or carbon nanomaterials [21] synthesized under high pressure, and also gives quadratic field dependence [22]:…”

Section: Resultsmentioning

confidence: 99%

Magnetoresistance of the high-pressure ferromagnetic phases (GaSb)₂M (M=Cr,Mn)

Pronin

Kondrin

Gizatullin

et al. 2014

J. Phys.: Condens. Matter

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For the first time magnetoresistance of the ferromagnetic high-pressure phases (GaSb)2M (M=Cr,Mn) has been measured in a wide range of temperature and magnetic field. It was found that the magnetic field dependencies of resistivity of both systems contain several contributions, including relatively smaller s-d exchange (Yosida-type) components in low fields and a quadratic positive term (PMR) in the low temperature region. The magnitude of the predominated negative term (NMR), which can be attributed to the quantum corrections effects, demonstrates a peak in the vicinity of Curie temperature.

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“…In pure carbon samples, hopping with a constant and/or variable jump length due to the tunneling between the nearest localization centers was observed [11]. It is shown that charge carrier transport in the composites with OLC can be performed by the variable range hopping and tunneling between OLC clusters and inside the clusters [10][11][12][13][14], while in the composites with MWCNTs carrier transport occurs by tunneling through the potential barriers between MWCNTs [15][16][17]. Also, thermally activated conduction at higher temperatures was observed, and the voltage°uctuations directly in°uenced the tunneling probability [17].…”

Section: Introductionmentioning

confidence: 99%

Low Frequency Noise and Resistivity Characteristics of Hybrid Composites with Onion-Like Carbon and Multi-Walled Carbon Nanotubes

et al. 2019

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The comprehensive study of resistivity and low frequency (10[Formula: see text]Hz–20[Formula: see text]kHz) noise characteristics of hybrid polymer composites with multi-walled carbon nanotubes (MWCNTs) and onion-like carbon (OLC) particles in one material have been carried out in the wide temperature range ((75–380) K). The characteristic dependences on the fillers density and the dominant conduction mechanisms were investigated. At low temperature ((75–170) K), the resistivity dependences on temperature are well-fitted by the Mott’s formula for the quasi-one-dimensional charge carrier variable range hopping and Arrhenius law. At temperatures above 300[Formula: see text]K, the resistance increases with temperature due to matrix expansion and decreases due to the onset of the conductivity in the matrix. Low frequency voltage noise spectra comprise of 1/[Formula: see text] and Lorentzian-type components with characteristic times in the range from 0.1[Formula: see text][Formula: see text]s to 10[Formula: see text][Formula: see text]s; the noise spectral density in the region of Ohmic resistance is proportional to the voltage square. Therefore, thermally activated charge carrier capture centers randomly modulate the sample’s resistance and control the carrier hopping. Impulse noise and more sudden changes of the noise characteristics were observed at the temperatures, where the conduction mechanisms change.

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Electron transport in carbynes modified under high pressure

Cited by 12 publications

References 10 publications

Activated hopping transport in nematic conducting aerogel at low temperatures

Activated hopping transport in nematic conducting aerogel at low temperatures

Magnetoresistance of the high-pressure ferromagnetic phases (GaSb)₂M (M=Cr,Mn)

Low Frequency Noise and Resistivity Characteristics of Hybrid Composites with Onion-Like Carbon and Multi-Walled Carbon Nanotubes

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Electron transport in carbynes modified under high pressure

Cited by 12 publications

References 10 publications

Activated hopping transport in nematic conducting aerogel at low temperatures

Activated hopping transport in nematic conducting aerogel at low temperatures

Magnetoresistance of the high-pressure ferromagnetic phases (GaSb)2M (M=Cr,Mn)

Low Frequency Noise and Resistivity Characteristics of Hybrid Composites with Onion-Like Carbon and Multi-Walled Carbon Nanotubes

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Magnetoresistance of the high-pressure ferromagnetic phases (GaSb)₂M (M=Cr,Mn)