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.

C/SiC Multilayer Coating for the Oxidation Resistance of C-C Composite by Low Pressure Chemical Vapor Deposition

2003 ◽  
Vol 17 (08n09) ◽  
pp. 1223-1228 ◽  
Author(s):  
J. I. Kim ◽  
W. J. Kim ◽  
D. J. Choi ◽  
J. Y. Park ◽  
W. S. Ryu
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Multilayer Coating ◽  
Chemical Vapor ◽  
Low Pressure ◽  
Functionally Graded ◽  
Graded Materials ◽  
Pressure Chemical ◽  
Graded Layers ◽  
Compositional Distribution

Functionally graded materials (FGM) consisting of C and SiC were deposited between the carbon fiber reinforced carbon (C-C) composites and the SiC coating layer by low pressure chemical vapor deposition (LPCVD) method to reduce the thermal stress. The compositions of the graded layers could be easily controlled to various steps by manipulating the input ratio of CH 3 SiCl 3 to C 2 H 2. The residual stresses for the designed compositional distribution were calculated by finite element method (FEM). The designed FGM layers were coated experimentally on the C-C composites and the oxidation behavior of the composites was investigated.

Low-Temperature Chemical-Vapor-Deposition of Silicon-Nitride from Tetra-Silane and Hydrogen Azide

1992 ◽  
Vol 284 ◽  
Author(s):  
Ryoichi Ishihara ◽  
Hiroshi Kanoh ◽  
Yasutaka Uchida ◽  
Osamu Sugiura ◽  
Masakiyo Matsumura
Keyword(s):  
Chemical Vapor Deposition ◽  
Silicon Nitride ◽  
Vapor Deposition ◽  
Gate Dielectric ◽  
Chemical Vapor ◽  
Atomic Ratio ◽  
Breakdown Field ◽  
Silicon Thin Film ◽  
Silicon Nitride Films ◽  
Low Field

ABSTRACTSilicon nitride films have been successfully deposited at a temperature as low as 300°C by chemical-vapor-deposition using tctra-silane (Si4 H10) and hydrogen azidc (HN3). Atomic ratio (N/Si) of the film deposited at 400°C was 1.47, i.e., the film was N-rich. Total hydrogen content was about 25atomic%. The breakdown-field strength was 6.5MV/cm at leakage-current density of 1μA/cm2, and the low-field resistivity was more than 1015 Ωcm. Similar electrical characteristics were obtained from films deposited at a temperature range between 300°C and 500°C. Amorphous silicon thin-film transistors equipped with this film as the gate dielectric showed good transfer characteristics.

scholarly journals Single Crystalline Higher Manganese Silicide Nanowire Arrays with Outstanding Physical Properties through Double Tube Chemical Vapor Deposition

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1880
Author(s):  
Chin-Li Shen ◽  
Shu-Meng Yang ◽  
Kuo-Chang Lu
Keyword(s):  
Electron Microscopy ◽  
Chemical Vapor Deposition ◽  
Physical Properties ◽  
Vapor Deposition ◽  
Silicon Nanowire ◽  
Chemical Vapor ◽  
Nanowire Arrays ◽  
Higher Manganese Silicide ◽  
Single Crystalline ◽  
Manganese Silicide

In this work, we report a novel and efficient silicidation method to synthesize higher manganese silicide (HMS) nanowires with interesting characterization and physical properties. High density silicon nanowire arrays fabricated by chemical etching reacted with MnCl2 precursor through a unique double tube chemical vapor deposition (CVD) system, where we could enhance the vapor pressure of the precursor and provide stable Mn vapor with a sealing effect. It is crucial that the method enables the efficient formation of high quality higher manganese silicide nanowires without a change in morphology and aspect ratio during the process. X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were utilized to characterize the HMS nanowires. High-resolution TEM studies confirm that the HMS nanowires were single crystalline Mn27Si47 nanowires of Nowotny Chimney Ladder crystal structures. Magnetic property measurements show that the Mn27Si47 nanowire arrays were ferromagnetic at room temperature with a Curie temperature of over 300 K, highly depending on the relationship between the direction of the applied electric field and the axial direction of the standing nanowire arrays. Field emission measurements indicate that the 20 μm long nanowires possessed a field enhancement factor of 3307. The excellent physical properties of the HMS nanowires (NWs) make them attractive choices for applications in spintronic devices and field emitters.

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.

In situ study of electron beam-induced chemical vapor deposition of Au in an environmental TEM

1995 ◽  
Vol 53 ◽  
pp. 256-257
Author(s):  
J. Drucker ◽  
R. Sharma ◽  
J. Kouvetakis ◽  
K.H.J. Weiss
Keyword(s):  
Electron Beam ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Quantum Effect ◽  
Line Drawing ◽  
Chemical Vapor ◽  
Environmental Cell ◽  
Engineering Changes ◽  
Kinetics Of

Patterning of metals is a key element in the fabrication of integrated microelectronics. For circuit repair and engineering changes constructive lithography, writing techniques, based on electron, ion or photon beam-induced decomposition of precursor molecule and its deposition on top of a structure have gained wide acceptance Recently, scanning probe techniques have been used for line drawing and wire growth of W on a silicon substrate for quantum effect devices. The kinetics of electron beam induced W deposition from WF6 gas has been studied by adsorbing the gas on SiO2 surface and measuring the growth in a TEM for various exposure times. Our environmental cell allows us to control not only electron exposure time but also the gas pressure flow and the temperature. We have studied the growth kinetics of Au Chemical vapor deposition (CVD), in situ, at different temperatures with/without the electron beam on highly clean Si surfaces in an environmental cell fitted inside a TEM column.

The relaxation of compressive biaxial strains in SOS via microtwins

1989 ◽  
Vol 47 ◽  
pp. 608-609
Author(s):  
M. E. Twigg ◽  
E. D. Richmond ◽  
J. G. Pellegrino
Keyword(s):  
Thin Film ◽  
Chemical Vapor Deposition ◽  
Molecular Beam Epitaxy ◽  
Compressive Stress ◽  
Vapor Deposition ◽  
Partial Dislocation ◽  
Molecular Beam ◽  
Volume Fraction ◽  
Chemical Vapor ◽  
Silicon Thin Film

For heteroepitaxial systems, such as silicon on sapphire (SOS), microtwins occur in significant numbers and are thought to contribute to strain relief in the silicon thin film. The size of this contribution can be assessed from TEM measurements, of the differential volume fraction of microtwins, dV/dν (the derivative of the microtwin volume V with respect to the film volume ν), for SOS grown by both chemical vapor deposition (CVD) and molecular beam epitaxy (MBE).In a (001) silicon thin film subjected to compressive stress along the [100] axis , this stress can be relieved by four twinning systems: a/6[211]/( lll), a/6(21l]/(l1l), a/6[21l] /( l1l), and a/6(2ll)/(1ll).3 For the a/6[211]/(1ll) system, the glide of a single a/6[2ll] twinning partial dislocation draws the two halves of the crystal, separated by the microtwin, closer together by a/3.

Coating of continuous carbon fibers with double layers by chemical vapor deposition

2001 ◽  
Vol 11 (PR3) ◽  
pp. Pr3-885-Pr3-892 ◽  
Author(s):  
N. Popovska ◽  
S. Schmidt ◽  
E. Edelmann ◽  
V. K. Wunder ◽  
H. Gerhard ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Carbon Fibers ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Double Layers
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