Thermal instability of field emission from carbon nanotubes

Бочаров, Г. С.; Eletskii, Aleksandr V.

doi:10.1134/s1063784207040160

Cited by 30 publications

(18 citation statements)

References 14 publications

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“…At the selected values of k0 and  in the temperature range 200-1000 K, the thermal conductivity coefficient k lies in the range 55 ÷ 830 W/(m  K). This corresponds to the literature data according to which k can vary from 25 to 3000 W/(mK) [25] . The results of the calculations are shown in cooling, no Nottingham effect, the thermal conductivity coefficient and the resistance of CNTs are constant [21]:…”

Section: Calculation Of the Heating Temperature Of The End Of A Singlsupporting

confidence: 67%

“…It is assumed that the temperature of the nanotube end, which is in contact with the substrate, is equal to the temperature of the substrate. The temperature of the opposite end was calculated by solving the heat-transfer equation taking into account the radiative cooling and the release of heat, which is caused by the current flow [21,25] :…”

Section: Calculation Of the Heating Temperature Of The End Of A Singlmentioning

confidence: 99%

“…However, for the case with CNTs there is a temperature dependence of k and R, therefore the results of [21] should be considered as approximate. It was assumed in [25] that the thermal conductivity coefficient k and the resistance R are described by power functions of temperature. For the case:…”

Section: Calculation Of the Heating Temperature Of The End Of A Singlmentioning

confidence: 99%

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Effect of heating and resistance on emission properties of carbon nanotubes

Bulyarskiy

Дудин

Lakalin

et al. 2018

CAN

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We have studied the effect of the series resistance on the heating of the cathode, which is based on carbon nanotubes and serves to realize the field emission of electrons into the vacuum. The experiment was performed with the single multi-walled carbon nanotube (MCNT) that was separated from the array grown by CVD method with thin-film Ni-Ti catalyst (nickel 4 nm / Ti 10 nm). The heating of the cathode leads to the appearance of a current of the thermionic emission. The experimental voltage current characteristic exhibited the negative resistance region caused by thermal field emission. This current increases strongly with increasing voltage and contributes to the degradation of the cold emitter. The calculation of the temperature of the end of the cathode is made taking into account the effect of the phenomenon that warms up and cools the cathode. We have developed a method for processing of the emission volt-ampere characteristics of a cathode, which relies on a numerical calculation of the field emission current and the comparison of these calculations with experiments. The model of the volt-ampere characteristic takes into account the CNT’s geometry, properties, its contact with the catalyst; heating and simultaneous implementation of the thermionic and field emission. The calculation made it possible to determine a number of important parameters, among which the voltage and current of the beginning of thermionic emission, the temperature distribution along the cathode, the resistance of the nanotube. The phenomenon of thermionic emission from CNT’s was investigated experimentally and theoretically. The conditions of this type emission occurrence were defined. The results of the study could form the basis of theory of CNT emitter’s degradation.

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Section: Calculation Of the Heating Temperature Of The End Of A Singlsupporting

confidence: 67%

Section: Calculation Of the Heating Temperature Of The End Of A Singlmentioning

confidence: 99%

Section: Calculation Of the Heating Temperature Of The End Of A Singlmentioning

confidence: 99%

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Effect of heating and resistance on emission properties of carbon nanotubes

Bulyarskiy

Дудин

Lakalin

et al. 2018

CAN

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“…The basic mecha nism of the degradation of CNT based emitters that restricts the emission current is the thermal decompo sition of nanotubes because of Joule heat. Detailed experimental [6,13] and theoretical [6,14,15] inves tigations demonstrate that this effect has a character of thermal instability and manifests itself at a certain crit ical emission current, when the thermal balance between the ohmic heating of CNTs during emission and the heat removal via thermal conduction is vio lated. The threshold character of this effect can be used to avoid the thermal decomposition of CNTs by operating at voltages (currents) below the critical value.…”

Section: Introductionmentioning

confidence: 99%

Degradation of a carbon nanotube-based field-emission cathode during ion sputtering

Бочаров

Eletskii

2012

Tech. Phys.

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The degradation rate of carbon nanotubes (CNTs) in an electron field emitter is calculated. The degradation mechanism is taken to be the sputtering of the CNT surface by the ions that result from the ion ization of residual gas molecules by an electron impact. The degradation rate and the corresponding CNT lifetime are calculated as a function of the nanotube geometry, the applied voltage, the pressure and kind of a residual gas, the interelectrode gap, and the nanotube array density. The obtained strong dependence of the degradation rate on the applied voltage is caused by a sharp character of the I-V emission characteristic determined by the Fowler-Nordheim relationship. The dependence of the degradation rate on the interelec trode gap is induced by the corresponding dependence of the probability of reaching the CNT surface.

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“…12,13 Coupled thermal-electrical effects play important roles in current emission performance as well as the stability of carbon nanofiber based field emitters. [14][15][16][17] There has also been interest in understanding and controlling the local temperature increases within electrically driven nanoscale wires and metallic interconnects. 18 Thermal stability is one of the key challenges in nanoscale devices made of novel materials, such as graphene [19][20][21] and organic materials.…”

Section: Introductionmentioning

confidence: 99%

Effects of temperature dependence of electrical and thermal conductivities on the Joule heating of a one dimensional conductor

Antoulinakis

Chernin

Zhang

et al. 2016

Journal of Applied Physics

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We examine the effects of temperature dependence of the electrical and thermal conductivities on Joule heating of a one-dimensional conductor by solving the coupled non-linear steady state electrical and thermal conduction equations. The spatial temperature distribution and the maximum temperature and its location within the conductor are evaluated for four cases: (i) constant electrical conductivity and linear temperature dependence of thermal conductivity, (ii) linear temperature dependence of both electrical and thermal conductivities, (iii) the Wiedemann-Franz relation for metals, and (iv) polynomial fits to measured data for carbon nanotube fibers and for copper. For (i) and (ii), it is found that there are conditions under which no steady state solution exists, which may indicate the possibility of thermal runaway. For (i), analytical solutions are constructed, from which explicit expressions for the parameter bounds for the existence of steady state solutions are obtained. The shifting of these bounds due to the introduction of linear temperature dependence of electrical conductivity (case (ii)) is studied numerically. These results may provide guidance in the design of circuits and devices in which the effects of coupled thermal and electrical conduction are important.

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Thermal instability of field emission from carbon nanotubes

Cited by 30 publications

References 14 publications

Effect of heating and resistance on emission properties of carbon nanotubes

Effect of heating and resistance on emission properties of carbon nanotubes

Degradation of a carbon nanotube-based field-emission cathode during ion sputtering

Effects of temperature dependence of electrical and thermal conductivities on the Joule heating of a one dimensional conductor

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