Synthesis of functionally graded metal-ceramic microstructures by chemical vapor deposition

1995 ◽  
Vol 10 (12) ◽  
pp. 3000-3002 ◽  
Author(s):  
W.Y. Lee ◽  
Y.W. Bae ◽  
K.L. More
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Functionally Graded ◽  
Ni Substrate ◽  
Cvd Method ◽  
Metal Ceramic ◽  
Composite Microstructure ◽  
Coating Matrix ◽  
Nial Matrix

A composite microstructure consisting of small α-Al2O3 particles dispersed in a β-NiAl coating matrix was synthesized by chemical vapor deposition (CVD). White the surface of a pure Ni substrate was being reacted with AlCl3 and H2 to form β-NiAl at a temperature of 1050 °C, the partial pressure of CO2 in the reactor was controlled via pulsing to nucleate and disperse 50 to 500 nm α-Al2O3 particles in the β-NiAl matrix. The relative amount of the α-Al2O3 phase increased with coating thickness as the rate of the β-NiAl formation decreased with time. These experimental observations suggest that the synthesis of a graded composite microstructure by the CVD method is feasible.

High Band Gap Nanocrystalline Tungsten Carbide (nc-WC) Thin Films Grown by Hot Wire Chemical Vapor Deposition (HW-CVD) Method

2018 ◽  
Vol 10 (3) ◽  
pp. 03001-1-03001-6 ◽  
Author(s):  
Bharat Gabhale ◽  
◽  
Ashok Jadhawar ◽  
Ajinkya Bhorde ◽  
Shruthi Nair ◽  
...  
Keyword(s):  
Thin Films ◽  
Chemical Vapor Deposition ◽  
Tungsten Carbide ◽  
Band Gap ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Hot Wire ◽  
Cvd Method ◽  
High Band

Properties and Production Mechanism of Low-Temperature Deposited CAT-CVD Poly-Silicon films

1992 ◽  
Vol 283 ◽  
Author(s):  
Hideki Matsumura ◽  
Yoichi Hosoda ◽  
Seijiro Furukawa
Keyword(s):  
Chemical Vapor Deposition ◽  
Low Temperature ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Gas Pressure ◽  
Silicon Films ◽  
Production Mechanism ◽  
Cvd Method ◽  
Poly Silicon ◽  
Deposition Conditions

ABSTRACTPoly-silicon films are obtained at temperatures as low as 400 °C by the catalytic chemical vapor deposition (cat-CVD) method, in which deposition gases are decomposed by the catalytic or pyrolytic reactions with a heated catalyzer near substrates. It is found that there are roughly two modes of deposition conditions such as low gas pressure mode and high gas pressure mode for obtaining poly-silicon films, and also that the Hall mobility of the cat-CVD poly-silicon films of low gas pressure mode sometimes exceeds over 100 cm2/Vs.

Synthesis of Carbon Nanotubes from Polycyclic Compounds by CVD Method

2006 ◽  
Vol 320 ◽  
pp. 163-166 ◽  
Author(s):  
Koji Yamada ◽  
Kentaro Abe ◽  
Masafumi Mikami ◽  
Morihiro Saito ◽  
Jun Kuwano
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Quartz Substrate ◽  
Chemical Vapor ◽  
Polycyclic Compounds ◽  
Cvd Method ◽  
Multi Walled Carbon Nanotubes ◽  
Synthesis Of Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Multi-walled carbon nanotubes (MWCNTs) were synthesized from camphor by a chemical vapor deposition (CVD) method in a range of 750-900. The catalyst was fed in three ways: (a) a sputtered Fe-film on a quartz substrate (b) vaporized ferrocene in an Ar flow; (c) both of (a) and (b). In the case (c), highly pure, dense and aligned MWCNT arrays formed on the quartz substrate at 850, whereas nonaligned MWCNTs formed in the cases (a) and (b).

scholarly journals Morphology Evolution of Mn-Si Composition Gradient Micro/Nanomaterials Prepared by Oxygen Assisted Chemical Vapor Deposition

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Siwei Tang
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Atomic Ratio ◽  
Functionally Graded ◽  
Composition Gradient ◽  
Graded Materials ◽  
Manganese Powder ◽  
Shape Structure ◽  
Manganese Silicide

The micro/nanostructure of manganese silicide (Mn-Si) compounds with various morphologies (nanowires, films, particles, and polyhedron shape structure) has been synthesized through oxygen assisted chemical vapor deposition by changing the stacking geometry of manganese powder. Polyhedrons prepared in the Mn-Si contact area were identified to be chemical composition gradient functionally graded materials which were verified by analyzing atomic ratio of Mn/Si from top to bottom. Evolution of morphology greatly depended on the stacking shape correlated distance from precursor to the substrate, resulting in distinctive growth mechanisms. Main structures on the substrate have been verified to be Mn5Si3 and Mn4Si7 with different Mn stacking in bumps comparing to sole Mn4Si7 with flat surface.

Synthysis of S Doped Y-Junction Carbon Nanotubes by CVD Method

2011 ◽  
Vol 183-185 ◽  
pp. 1731-1735 ◽  
Author(s):  
Xia Yuan ◽  
Xiao Juan Wu ◽  
Yu Liang An ◽  
Qing Yi Hou
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Vapor Deposition ◽  
Carbon Disulfide ◽  
Growth Mechanism ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Processing Parameters ◽  
Structure And Morphology ◽  
Cvd Method

The sulfur-doped Y-junction carbon nanotubes (S-YCNTs) were prepared by chemical vapor deposition of carbon disulfide using Fe as catalyst. Sulfur can be incorporated into the nanotubes with an identifiable amount, forming sulfur-doped carbon nanotubes. The growth of asymmetrical Y-branches in the nanotubes may be related to the presence of sulfur from precursor. The structure and morphology of S-YCNTs can be controlled by processing parameters. The S-YCNTs were characterized by SEM, TEM, EDX, and XPS, respectively. The growth mechanism of S-YCNTs was discussed in terms of the role of sulfur from carbon feedstock.

Properties of I-Doped CuI Thin Films by Chemical Vapor Deposition (CVD)

2013 ◽  
Vol 832 ◽  
pp. 439-443 ◽  
Author(s):  
Nur Amalina Muhamad ◽  
Mohamad Rusop
Keyword(s):  
Thin Films ◽  
Chemical Vapor Deposition ◽  
Surface Morphology ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
High Current ◽  
Constant Voltage ◽  
Iodine Doping ◽  
Particle Structure ◽  
Cvd Method

In this paper, we present the properties of I-doped CuI thin films at different concentration of iodine dopant (e.g. 10mg, 20mg, 30mg, 40mg and 100mg). The doping of CuI was done by using double furnace chemical vapor deposition (CVD) method. The effects of I-doped CuI to its surface morphology and electrical were studied. The effect of iodine doping to surface morphology was measured by field emission scanning electron microscopy (FESEM). The morphology of all thin films shows insignificance changes in grain size, grain boundaries and particle structure as the doping concentration varies. For the electrical properties, high current at constant voltage of-5V to 5V was obtained. The resistivity of 10-1 was obtained for undoped CuI thin films. While, for the series of I-doped CuI thin films, the resistivity of 10-2 was obtained. The excess of hole conductor in the I-doped CuI thin films enhances the electrical conductivity of the films.

2-Inch 4H-SiC Homoepitaxial Layer Grown on On-Axis C-Face Substrate by CVD Method

2005 ◽  
Vol 483-485 ◽  
pp. 93-96 ◽  
Author(s):  
Kazutoshi Kojima ◽  
Hajime Okumura ◽  
Satoshi Kuroda ◽  
Kazuo Arai ◽  
Akihiko Ohi ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Surface Morphology ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Spiral Growth ◽  
Layer Surface ◽  
Screw Dislocations ◽  
Specular Surface ◽  
Homoepitaxial Growth ◽  
Cvd Method

Homoepitaxial growth was carried out on 4H-SiC on-axis substrate by horizontal hot wall chemical vapor deposition. By using carbon face substrate, specular surface morphology of a wide area of up to 80% of a 2-inch epitaxial wafer was obtained at a low C/Si ratio growth condition of 0.6. The Micropipe in on-axis substrate was indicated to be filled with spiral growth and to be dissociated into screw dislocations during epitaxial growth. It was found that the appearance of basal plane dislocations on the epitaxial layer surface can be prevented by using an on-axis substrate.

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