Influence of the gas phase composition on the properties of bimetallic Ag/Cu nanomaterials obtained via chemical vapor deposition

Polyhedron ◽  
2013 ◽  
Vol 65 ◽  
pp. 82-88 ◽  
Author(s):  
Iwona B. Szymańska
Keyword(s):  
Phase Composition ◽  
Chemical Vapor Deposition ◽  
Gas Phase ◽  
Vapor Deposition ◽  
Chemical Vapor

Effects of Feed Gas Composition and Catalyst Thickness on Carbon Nanotube and Nanofiber Synthesis by Plasma Enhanced Chemical Vapor Deposition

2008 ◽  
Vol 8 (6) ◽  
pp. 3068-3076 ◽  
Author(s):  
R. K. Garg ◽  
S. S. Kim ◽  
D. B. Hash ◽  
J. P. Gore ◽  
T. S. Fisher
Keyword(s):  
Carbon Nanotubes ◽  
Phase Composition ◽  
Chemical Vapor Deposition ◽  
Carbon Nanotube ◽  
Gas Phase ◽  
Vapor Deposition ◽  
Computational Study ◽  
Chemical Vapor ◽  
Gas Composition ◽  
Hydrogen Mixture

Many engineering applications require carbon nanotubes with specific characteristics such as wall structure, chirality and alignment. However, precise control of nanotube properties grown to application specifications remains a significant challenge. Plasma-enhanced chemical vapor deposition (PECVD) offers a variety of advantages in the synthesis of carbon nanotubes in that several important synthesis parameters can be controlled independently. This paper reports an experimental study of the effects of reacting gas composition (percentage methane in hydrogen) and catalyst film thickness on carbon nanotube (CNT) growth and a computational study of gas-phase composition for the inlet conditions of experimentally observed carbon nanotube growth using different chemical reaction mechanisms. The simulations seek to explain the observed effects of reacting gas composition and to identify the precursors for CNT formation. The experimental results indicate that gas-phase composition significantly affects the synthesized material, which is shown to be randomly aligned nanotube and nanofiber mats for relatively methane-rich inlet gas mixtures and non-tubular carbon for methane-lean incoming mixtures. The simulation results suggest that inlet methane-hydrogen mixture coverts to an acetylene-methane-hydrogen mixture with minor amounts of ethylene, hydrogen atom, and methyl radical. Acetylene appears to be the indicator species for solid carbon formation. The simulations also show that inlet methane-hydrogen mixture does not produce enough gas-phase precursors needed to form quality CNTs below 5% CH4 concentrations in the inlet stream.

scholarly journals Machine learning and a computational fluid dynamic approach to estimate phase composition of chemical vapor deposition boron carbide

2021 ◽  
Vol 10 (3) ◽  
pp. 537-550
Author(s):  
Qingfeng Zeng ◽  
Yong Gao ◽  
Kang Guan ◽  
Jiantao Liu ◽  
Zhiqiang Feng
Keyword(s):  
Phase Composition ◽  
Chemical Vapor Deposition ◽  
Boron Carbide ◽  
Computational Fluid Dynamic ◽  
Vapor Deposition ◽  
Fluid Dynamic ◽  
Chemical Vapor ◽  
Sensitivity Coefficient ◽  
Design Solution ◽  
Novel Approach

AbstractChemical vapor deposition is an important method for the preparation of boron carbide. Knowledge of the correlation between the phase composition of the deposit and the deposition conditions (temperature, inlet gas composition, total pressure, reactor configuration, and total flow rate) has not been completely determined. In this work, a novel approach to identify the kinetic mechanisms for the deposit composition is presented. Machine leaning (ML) and computational fluid dynamic (CFD) techniques are utilized to identify core factors that influence the deposit composition. It has been shown that ML, combined with CFD, can reduce the prediction error from about 25% to 7%, compared with the ML approach alone. The sensitivity coefficient study shows that BHCl2 and BCl3 produce the most boron atoms, while C2H4 and CH4 are the main sources of carbon atoms. The new approach can accurately predict the deposited boron–carbon ratio and provide a new design solution for other multi-element systems.

scholarly journals Gas Phase Chemistry of Trimethylboron in Thermal Chemical Vapor Deposition

2017 ◽  
Vol 121 (47) ◽  
pp. 26465-26471 ◽  
Author(s):  
Mewlude Imam ◽  
Laurent Souqui ◽  
Jan Herritsch ◽  
Andreas Stegmüller ◽  
Carina Höglund ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Gas Phase ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Thermal Chemical Vapor Deposition ◽  
Gas Phase Chemistry ◽  
Phase Chemistry

scholarly journals Gas-phase aluminium acetylacetonate decomposition: Revision of the current mechanism by VUV synchrotron radiation

2021 ◽  
Author(s):  
Sebastian Grimm ◽  
Seung-Jin Baik ◽  
Patrick Hemberger ◽  
Andras Bodi ◽  
Andreas Kempf ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Synchrotron Radiation ◽  
Gas Phase ◽  
Vapor Deposition ◽  
Aluminium Oxide ◽  
Chemical Vapor ◽  
Phase Decomposition ◽  
Common Precursor ◽  
Current Mechanism

Although aluminium acetylacetonate, Al(C5H7O2)3, is a common precursor for chemical vapor deposition (CVD) of aluminium oxide, its gas phase decomposition is not very well investigated. Here, we studied its thermal...

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