Measurement and control of the substrate temperature in vertical graphene nanosheets deposition

Vachkov, V; Kiss’ovski, Zh

doi:10.1088/1742-6596/1492/1/012061

Cited by 2 publications

(2 citation statements)

References 3 publications

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“…We control the heating by controlling the power fed to the heater. The substrate temperature is monitored precisely by a thermocouple system keeping the temperature within the desired range (600 -700 C) [3]. The reflected and forward microwave power is measured by an HP 437B power meter through a Pasternack PE 2219-30 directional coupler; the data received are used to better match the plasma source by means of a Maury 1878C triple stub.…”

Section: Experimental Setup and Diagnosticsmentioning

confidence: 99%

Double-discharge plasma system for deposition of carbon nanostructures

Marinov

Vachkov

Ivanov

et al. 2022

J. Phys.: Conf. Ser.

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Deposition of carbon nanostructures from ethanol precursor at atmospheric pressure can be enhanced via the use of a double-discharge system - a microwave and a DC discharge. We used a surface-wave discharge at a frequency of 2.45 GHz in a gas mixture of Ar, H2 and C2H5OH to create a plasma column in a small-diameter ceramic tube and a plasma plume above it. The plume spectra in the UV/Vis range were measured by an optical system with an iHR550 spectrometer; the gas temperature and the electron temperature and density were calculated from the emission lines. The high gas temperature T g ∼3000 K and electron density (∼6×1020 m3) in the microwave plasma plume cause an effective dissociation of the ethanol even at low levels of absorbed power (10 W) and a strong carbon Swan band is registered in the spectrum. Transporting the created neutral and charged particles to the substrate at atmospheric pressure is difficult due to their short mean-free-path; we, therefore, applied an additional DC discharge. This two-discharge system allows more reactive species and ions from the ethanol decomposition to reach the substrate, thus speeding up the deposition of carbon nanostructures. Such structures were deposited on Ni foil and Ni foam substrates under fixed plasma parameters and controlled substrate temperature. The morphology of the produced graphene structures was studied using SEM and Raman spectroscopy.

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Section: Experimental Setup and Diagnosticsmentioning

confidence: 99%

Double-discharge plasma system for deposition of carbon nanostructures

Marinov

Vachkov

Ivanov

et al. 2022

J. Phys.: Conf. Ser.

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“…These device integrated the DC amplifier, cold-junction temperature sensor with compensating circuits, A/D converter with internal reference as well as the specialized digital interface. Represented by the MAX31855 from Analog Devices, its input can be directly connected to the thermocouple, and the output is an SPI bus digital interface, which has the advantages of high integration and simple peripheral circuitry in hardware [12]. Some other types like MAX6675 and MAX31856 are also commonly adopted.…”

Section: Introductionmentioning

confidence: 99%

Research of transient temperature measuring based on thin-film thermocouple and Wi-Fi wireless DAQ method

2023

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The thin-film thermocouple temperature sensor is a new type of temperature sensor which was emerged with the development of thin-film materials. It features on a small heat capacity and a rapid response speed for transient temperature measurement on the surface of objects. The existing temperature data acquisition systems for filamentary thermocouples do not yet meet the conditions for distortion-free measurement of transient temperature signals in terms of sampling frequency and transmission rate. In addition, it is less flexible in terms of data transmission methods, while the cold end of the thermocouple compensation method has not yet compensated for the non-linear phenomenon of thermocouples, which affects the final measurement accuracy. This paper devised a wireless temperature data acquisition system for K-type thin-film thermocouples using a Wi-Fi wireless network to transmit sampling data, then applied the devised system as a data acquisition method to investigate the measurement of transient temperatures in conjunction with thin-film thermocouple sensors. The results of performance test indicated that the devised system is capable of transient temperature measurement of K-type thin-film thermocouples in the range of 0–650°C with a maximum sampling rate of 100 kHz, a temperature resolution of 0.16 degrees Celsius, an accuracy of 0.2% after non-linear compensation and the ability to measure transient temperature signals with a maximum frequency component of 25 kHz. Taken advantage of the devised wireless data acquisition system to measure the impulse response of a thin-film thermocouple sensor specimen, the meausured response curve is consistent with the law of first-order system, and the time constant of the sensor was obtained as approximately 1.16 ms. A comparison between the existing data acquisition apparatuses of type K thermocouple was made. The limitations of the devised system are also discussed.

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Measurement and control of the substrate temperature in vertical graphene nanosheets deposition

Cited by 2 publications

References 3 publications

Double-discharge plasma system for deposition of carbon nanostructures

Double-discharge plasma system for deposition of carbon nanostructures

Research of transient temperature measuring based on thin-film thermocouple and Wi-Fi wireless DAQ method

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