Nucleation and growth of silicon on ceramic substrates by RTCVD at atmospheric pressure

2001 ◽  
Vol 11 (PR3) ◽  
pp. Pr3-301-Pr3-306 ◽  
Author(s):  
A. Slaoui ◽  
S. Bourdais
Keyword(s):  
Atmospheric Pressure ◽  
Nucleation And Growth ◽  
Ceramic Substrates

Initial Stages in the Growth of Oxide Thin Films by CVD

1989 ◽  
Vol 168 ◽  
Author(s):  
Lisa A. Tietz ◽  
Scott R. Summerfelt ◽  
Gerald R. English ◽  
C. Barry Carter
Keyword(s):  
Thin Films ◽  
Nucleation And Growth ◽  
Low Energy ◽  
Transparent Ceramic ◽  
Oxide Thin Films ◽  
Island Growth ◽  
Ceramic Substrates ◽  
Surface Steps ◽  
Preferential Nucleation ◽  
Growth Habits

AbstractA technique has been developed for studying the early stages of heteroepitactic nucleation and growth of oxide thin films by TEM using direct deposition onto electron-transparent ceramic substrates. Observations of α-Fe2O3 island growth on four orientations of α-Al2O3 – (0001), {1102}, {1010}, and {1120} – are reported. Moir6 fringes and selected-area diffraction are used to show heteroepitactic growth. Island morphology is compared to known growth habits of hematite crystals. Preferential nucleation of islands at low-energy sites (e.g. surface steps) is also demonstrated.

scholarly journals The Chemical Vapor Deposition of Zirconium Carbide onto Ceramic Substrates

1998 ◽  
Vol 555 ◽  
Author(s):  
John A. Glass ◽  
Nick Palmisiano ◽  
R. Edward Welsh
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Atmospheric Pressure ◽  
Zirconium Carbide ◽  
Chemical Vapor ◽  
High Melting Point ◽  
Ceramic Substrates ◽  
Film Density ◽  
Compositional Changes ◽  
Controlled Preparation

AbstractZirconium carbide is an attractive ceramic material due to its unique properties such as high melting point, good thermal conductivity, and chemical resistance. The controlled preparation of zirconium carbide films of superstoichiometric, stoichiometric, and substoichiometric compositions has been achieved utilizing zirconium tetrachloride and methane precursor gases in an atmospheric pressure high temperature chemical vapor deposition system. Laminar and equiaxial microcrystalline morphologies were obtained for superstoichiometric and substoichiometric zirconium carbide; respectively, allowing cursory metallographic identification of composition. Observed reductions in film density associated with zirconium carbide films that contain additional free carbon or excess zirconium are reported. These changes in film density were found to be consistent with compositional changes. An apparently linear relationship (correlation of 0.99) between methane flow in this chemical vapor deposition system and zirconium carbide stoichiometry in the substoichiometric range deposited above ZrC0.61 has been observed.

Facile and one-pot solution synthesis of several kinds of 3D hierarchical flower-like α-Bi2O3 microspheres

2016 ◽  
Vol 09 (05) ◽  
pp. 1650059 ◽  
Author(s):  
Yajun Wang ◽  
Zexue Li ◽  
Haiyang Yu ◽  
Changgen Feng
Keyword(s):  
Self Assembly ◽  
Atmospheric Pressure ◽  
Three Dimensional ◽  
Water System ◽  
Nucleation And Growth ◽  
Synthesis Process ◽  
Solution Synthesis ◽  
One Pot ◽  
Capping Agents ◽  
Precipitation Synthesis

Several kinds of three-dimensional (3D) hierarchical constructed flower-like [Formula: see text]-Bi2O3 microspheres were prepared successfully via a simple solution precipitation synthesis at 95[Formula: see text]C and ambient atmospheric pressure in 1[Formula: see text]h. The synthesis process was operated in ethanol–water system as solvent with the assistance of glycerin and oleic acid as capping agents. These flower-like [Formula: see text]-Bi2O3 architectures with diameter of several micrometers were 3D self-assembled from nanorods or nanocubes step by step. By adjusting the concentration of the capping agents, various flower-like [Formula: see text]-Bi2O3 microspheres were obtained. The formation of the flower-like superstructures was attributed to the modification of nucleation and growth kinetics, and the guidance of self-assembly approach by capping agents. The formation mechanism of these microstructures was discussed briefly.

Growth of Monolayer WS2 Single Crystals with Atmospheric Pressure CVD: Role of Temperature

MRS Advances ◽  
2019 ◽  
Vol 4 (3-4) ◽  
pp. 255-262
Author(s):  
Yong Xie ◽  
Guanfei Wang ◽  
Zhan Wang ◽  
Tang Nan ◽  
Haolin Wang ◽  
...  
Keyword(s):  
Vapor Deposition ◽  
Atmospheric Pressure ◽  
Chemical Vapor ◽  
Optical Microscope ◽  
Nucleation And Growth ◽  
Pressure Chemical ◽  
Different Temperatures ◽  
Individual Domain

ABTRACTIt has been demonstrated that the introduction of NaCl can significantly improve the quality of monolayer WS2 at the growth temperatures ranging from 700°C to 850°C by atmospheric pressure chemical vapor deposition (APCVD) without the assistant of hydrogen. Here, the influence of NaCl on the nucleation and growth of WS2 has been thoroughly investigated. The morphology and quality of WS2 grown with different temperatures are discussed by optical microscope, Raman and Photoluminescence (PL) spectra. It was found that amount of NaCl can efficiently influence the morphology and quality of WS2 crystals. PL intensity of WS2 crystal increases around three times from the center region to the edge of an individual domain, which may be attributed to the appearance of small triangle hollows formed during the growth at the edge of single crystal WS2.

Effect of Atmosphere on Duplex Oxide Formed on 9Cr Steel at 550 °C

2020 ◽  
Vol 856 ◽  
pp. 15-20
Author(s):  
Mohammad Hassan Shirani Bidabadi ◽  
Abdul Rehman ◽  
Yu Zheng ◽  
Liang Yang ◽  
Somrerk Chandra-Ambhorn ◽  
...  
Keyword(s):  
Oxide Scale ◽  
Cooling Rate ◽  
Growth Rates ◽  
Atmospheric Pressure ◽  
Nucleation And Growth ◽  
Outer Scale ◽  
Breakaway Oxidation ◽  
9Cr Steel ◽  
Oxide Phases ◽  
Duplex Oxide

Commercial F91 steel was exposed to atmospheric pressure CO2 and laboratory air at 550 °C for exposure times up to 1000 h. In both atmospheres, a Fe-rich duplex oxide scale formed, but with different morphology, oxide phases and growth rates. In CO2, the duplex morphology was observed at the onset of oxidation and it was found that the cooling rate affect the oxide phases formed on the outer scale. In air, the alloy initially formed a protective chromium rich oxide layer, followed by the nucleation and growth of duplex iron-rich oxide nodules at random locations, leading to breakaway oxidation. Alloy carburization was also observed in CO2 but not in air environment.

Morphological studies of III-V thin layers and SLS'S

1987 ◽  
Vol 45 ◽  
pp. 344-345
Author(s):  
K.M. Jones ◽  
M.M. Al-Jassim ◽  
J.M. Olson ◽  
A. Kibbler
Keyword(s):  
Atmospheric Pressure ◽  
Secondary Electron ◽  
Large Strain ◽  
Nucleation And Growth ◽  
Thin Layers ◽  
Growth Morphology ◽  
Structural Perfection ◽  
Quantum Well Structures ◽  
Morphological Studies ◽  
Strained Layer Superlattices

Thin layers of III-V semiconductors, such as quantum well structures and strained layer superlattices (SLS's), are currently of great interest. However, there have been widely scattered reports suggesting that thin layers and SLS's with arbitrarily large strain and thicknesses are difficult if not impossible to grow. In this work we studied the nucleation, morphology and structural perfection of a wide variety of thin layers in the GaAs/GalnAsP system. These epitaxial layers were grown by atmospheric pressure MOCVD. The GaAs/GalnAs system is mismatched through the entire compositional range, the extreme mismatch being 7% for GaAs/lnAs. The nucleation and growth morphology of GalnAs layers on GaAs were observed to be very strongly dependent on the mismatch (i.e. the In concentration x) This is clearly depicted in Fig. 1 which shows secondary electron micrographs of the surface of three GalnAs layers grown for 30 sec. using the same growth rate of 600 Å min-1.

Atmospheric pressure synthesis of nanosized ZSM-5 with enhanced catalytic performance for methanol to aromatics reaction

2014 ◽  
Vol 4 (11) ◽  
pp. 3840-3844 ◽  
Author(s):  
Kui Shen ◽  
Ning Wang ◽  
Weizhong Qian ◽  
Yu Cui ◽  
Fei Wei
Keyword(s):  
Atmospheric Pressure ◽  
Growth Process ◽  
Catalytic Performance ◽  
Nucleation And Growth ◽  
Synthetic Route ◽  
Excellent Performance ◽  
Pressure Synthesis ◽  
Atmospheric Pressure Synthesis

We develop an atmospheric pressure synthetic route for nanosized ZSM-5 with 100% yield, by decoupling its nucleation and growth process. The product exhibited excellent performance in catalytically transferring methanol into aromatics.

Chemical Vapor Deposition of Beta Silicon Carbide Epilayers Using the Single Source Precursor 1,2-Disilylethane

1992 ◽  
Vol 282 ◽  
Author(s):  
J. D. Parsons ◽  
D. A. Roberts ◽  
J. G. Wu ◽  
A. K. Chadda ◽  
H-S. Chen ◽  
...  
Keyword(s):  
Epitaxial Growth ◽  
Atmospheric Pressure ◽  
Epitaxial Film ◽  
Growth Parameters ◽  
Chemical Vapor ◽  
Growth Conditions ◽  
Nucleation And Growth ◽  
Film Properties ◽  
Single Source Precursor ◽  
Cvd Growth

ABSTRACTA β-SiC epitaxial growth process, using 1,2-disilylethane (DES), was developed. DSE was selected because it contains an equal number of C and Si atoms and its reported decomposition characteristics suggest that C and Si could be obtained from it at approximately equal rates. Repeatable nucleation and epitaxial growth conditions, giving complete substrate coverage and controlled growth, were established by atmospheric pressure CVD, in an inverted-vertical reactor. A substrate temperature of 1290± 10°C was found to be optimum for β-SiC epilayer nucleation and growth. The maximum β-SiC epitaxial growth rate obtained was 10μms/hr. Undoped β-SiC epilayers were n-type (n≈1016 cm−3 ). DSE synthesis, CVD growth parameters, SiC deposition characteristics and β-SiC epitaxial film properties are described.

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