scholarly journals Optical diagnostics of fullerene synthesis in the RF thermal plasma process

2005 ◽  
Vol 70 (1) ◽  
pp. 79-85 ◽  
Author(s):  
Biljana Todorovic-Markovic ◽  
Zoran Markovic ◽  
I. Mohai ◽  
Z. Károly ◽  
Z. Farkas ◽  
...  
Keyword(s):  
Thermal Plasma ◽  
Plasma Reactor ◽  
Plasma Temperature ◽  
Emission Spectra ◽  
Optical Emission ◽  
Graphite Powder ◽  
Inductively Coupled ◽  
Rf Thermal Plasma ◽  
Emission Study ◽  
Spectroscopy Studies

In this work, the results of an optical emission study of fullerene synthesis in an inductively coupled radio frequency thermal plasma reactor are presented. The emission spectroscopy studies, based on the use of the Swan C2 (0,1) and CN (0,0) vibration emission spectra, were carried out to determine the plasma temperature. The evaporation process of graphite powder was observed by scanning electron microscopy.

scholarly journals Influence of the precursor on fullerene synthesis in a RF thermal plasma reactor

2006 ◽  
Vol 12 (4) ◽  
pp. 246-250
Author(s):  
Zoran Markovic ◽  
Biljana Todorovic-Markovic ◽  
Ilona Mohai ◽  
Zoran Nikolic ◽  
Zsuzsana Farkas ◽  
...  
Keyword(s):  
Particle Size ◽  
Thermal Plasma ◽  
Atmospheric Pressure ◽  
Powder Processing ◽  
Plasma Reactor ◽  
Graphite Powder ◽  
Mean Particle Size ◽  
Pure Graphite ◽  
Rf Thermal Plasma ◽  
The Mean

Several graphite powders and mixtures (4827 Asbury Mills, KS4 and KS6 Timcal flake Alfa Aesar, graphite Aldrich, mixture of iron and KS4 powder) having different mean particle size were processed in a RF thermal plasma reactor at atmospheric pressure. It was found that the mean particle size of the precursors has an important, but not exclusive effect on the evaporation efficiency. The micro-structural orderliness of the precursors, which determines their thermal conductivity, is another important property that should be considered in the interpretation of the observed phenomena. In this study a mixture of iron and KS4 graphite proved to be the best precursor of fullerene synthesis. The maximum fullerene yield was 18.4%, which was higher compared to pure graphite powder processing in a RF reactor without the presence of iron.

Optical spectroscopic study of the radio-frequency oxygen thermal plasma evaporated YBa2Cu3O7−x

1993 ◽  
Vol 8 (4) ◽  
pp. 709-712 ◽  
Author(s):  
Shigenori Yuhya ◽  
Jiro Tsujino ◽  
Noriyuki Tatsumi ◽  
Yuh Shiohara
Keyword(s):  
Thermal Plasma ◽  
Stoichiometric Composition ◽  
Emission Spectra ◽  
Optical Emission ◽  
Lower Plasma ◽  
Rf Thermal Plasma ◽  
Emitting Species ◽  
Optical Emission Spectra ◽  
Deposited Film ◽  
Deposited Films

Optical emission spectroscopy of the rf thermal plasma evaporated YBa2Cu3O7−x has been investigated. The deposited films with the nearly stoichiometric composition could be obtained by using Y-rich powder. From the optical emission spectra, O, Y, Y+, Ba, Ba+, Cu, and YO as the emitting species were observed. The excitation temperature was lower for Y+ than for the other dissociated elements. The relative intensity for YO of a suboxide became larger with a lower plasma torch. It is thought that the deposited film that is poor in Y results from YO sticking to the substrate rather than Y or Y+.

Optical Emission Study of RF Thermal Plasma During Fullerene Synthesis

2005 ◽  
Vol 13 (3) ◽  
pp. 215-226 ◽  
Author(s):  
Z. Marković ◽  
B. Todorović‐Marković ◽  
I. Mohai ◽  
Z. Károly ◽  
Z. Farkas ◽  
...  
Keyword(s):  
Thermal Plasma ◽  
Optical Emission ◽  
Rf Thermal Plasma ◽  
Emission Study

Optical Emission Spectroscopic Study of the Synthesis of Titanium Boride Nanoparticles in RF Thermal Plasma Reactor

2017 ◽  
Vol 37 (6) ◽  
pp. 1491-1503 ◽  
Author(s):  
A. M. Keszler ◽  
P. Fazekas ◽  
E. Bódis ◽  
E. Drotár ◽  
Sz. Klébert ◽  
...  
Keyword(s):  
Spectroscopic Study ◽  
Thermal Plasma ◽  
Plasma Reactor ◽  
Optical Emission ◽  
Titanium Boride ◽  
Rf Thermal Plasma

scholarly journals Treatment of fly ash from power plants using thermal plasma

2017 ◽  
Vol 8 ◽  
pp. 1043-1048 ◽  
Author(s):  
Sulaiman Al-Mayman ◽  
Ibrahim AlShunaifi ◽  
Abdullah Albeladi ◽  
Imed Ghiloufi ◽  
Saud Binjuwair
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fly Ash ◽  
Thermal Plasma ◽  
Inductively Coupled Plasma ◽  
Power Plants ◽  
Plasma Reactor ◽  
Atomic Emission ◽  
Inductively Coupled ◽  
Scanning Electron

Fly ash from power plants is very toxic because it contains heavy metals. In this study fly ash was treated with a thermal plasma. Before their treatment, the fly ash was analyzed by many technics such as X-ray fluorescence, CHN elemental analysis, inductively coupled plasma atomic emission spectroscopy and scanning electron microscopy. With these technics, the composition, the chemical and physical proprieties of fly ash are determined. The results obtained by these analysis show that fly ash is mainly composed of carbon, and it contains also sulfur and metals such as V, Ca, Mg, Na, Fe, Ni, and Rh. The scanning electron microscopy analysis shows that fly ash particles are porous and have very irregular shapes with particle sizes of 20–50 μm. The treatment of fly ash was carried out in a plasma reactor and in two steps. In the first step, fly ash was treated in a pyrolysis/combustion plasma system to reduce the fraction of carbon. In the second step, the product obtained by the combustion of fly ash was vitrified in a plasma furnace. The leaching results show that the fly ash was detoxified by plasma vitrification and the produced slag is amorphous and glassy.

The effect of dielectric top lids on materials processing in a low frequency inductively coupled plasma (LF-ICP) reactor

2014 ◽  
Vol 32 ◽  
pp. 1460340
Author(s):  
J. W. M. Lim ◽  
C. S. Chan ◽  
L. Xu ◽  
S. Xu
Keyword(s):  
Thin Films ◽  
Inductively Coupled Plasma ◽  
Plasma Reactor ◽  
High Vacuum ◽  
Low Frequency ◽  
Optical Emission ◽  
Good Alternative ◽  
Plasma Sources ◽  
Inductively Coupled ◽  
Glass Substrates

The advent of the plasma revolution began in the 1970's with the exploitation of plasma sources for anisotropic etching and processing of materials. In recent years, plasma processing has gained popularity, with research institutions adopting projects in the field and industries implementing dry processing in their production lines. The advantages of utilizing plasma sources would be uniform processing over a large exposed surface area, and the reduction of toxic emissions. This leads to reduced costs borne by manufacturers which could be passed down as consumer savings, and a reduction in negative environmental impacts. Yet, one constraint that plagues the industry would be the control of contaminants in a plasma reactor which becomes evident when reactions are conducted in a clean vacuum environment. In this work, amorphous silicon (a-Si) thin films were grown on glass substrates in a low frequency inductively coupled plasma (LF-ICP) reactor with a top lid made of quartz. Even though the chamber was kept at high vacuum (~10−4 Pa), it was evident through secondary ion mass spectroscopy (SIMS) and Fourier-transform infra-red spectroscopy (FTIR) that oxygen contaminants were present. With the aid of optical emission spectroscopy (OES) the contaminant species were identified. The design of the LF-ICP reactor was then modified to incorporate an Alumina ( Al2O3 ) lid. Results indicate that there were reduced amounts of contaminants present in the reactor, and that an added benefit of increased power transfer to the plasma, improving deposition rate of thin films was realized. The results of this study is conclusive in showing that Al2O3 is a good alternative as a top-lid of an LF-ICP reactor, and offers industries a solution in improving quality and rate of growth of thin films.

Effect of Ion Bombardment on the Structure and Properties of PECVD SiO2

1994 ◽  
Vol 363 ◽  
Author(s):  
Jung H. Lee ◽  
Dong S. Kim ◽  
Young H. Lee
Keyword(s):  
Plasma Reactor ◽  
Substrate Surface ◽  
Emission Spectra ◽  
Optical Emission ◽  
Ion Bombardment ◽  
Ion Energy ◽  
On Line ◽  
Spectrometer Data ◽  
Optical Emission Spectra ◽  
Deposited Films

AbstractSiO2 films were deposited on silicon wafers at 25°C by plasma enhanced decomposition of tetraethoxysilane (TEOS) in a mixture of argon and oxygen. The deposition was performed in a rf-powered (13.56 MIHz) asymmetric plasma reactor. The effect of ion bombardment was evaluated by varying the ion energy flux (IEF) at the substrate surface from 0.93 to 9.94 W/cm2. On-line optical emission spectra (OES) revealed CO, CH, and H peaks whose absorption intensities increased with increasing applied power. On-line mass spectrometer data showed that the peak intensities of OC2H5, SiOH (m/e=45), and HSiOH (m/e=46) fragments decreased with increasing applied power indicating the decomposition of these species. FTIR spectra of the deposited films showed that the concentrations of Si-OH and trapped CO gases in the film decreased with increasing IEF. Also, the FTIR results and the refractive index measurements indicated that the film density increased as a function of IEF. The stoichiometry of the film did not change when IEF was below 2, but for IEF greater than 4.91 W/cm2, the film became Si-rich.

Effects of Precursors and Plasma Parameters on Fullerene Synthesis in RF Thermal Plasma Reactor

2006 ◽  
Vol 26 (6) ◽  
pp. 597-608 ◽  
Author(s):  
János Szépvölgyi ◽  
Zoran Marković ◽  
Biljana Todorović-Marković ◽  
Zoran Nikolić ◽  
Ilona Mohai ◽  
...  
Keyword(s):  
Thermal Plasma ◽  
Plasma Reactor ◽  
Plasma Parameters ◽  
Rf Thermal Plasma
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