Synthesis and Characterization of Exotic Carbon Fibers with Branched Spurs Using Nickel Catalyst Precursor

2013 ◽  
Vol 645 ◽  
pp. 3-9
Author(s):  
Qian Zhang ◽  
Qiu Xiang Wang ◽  
Hong Zhou Dong ◽  
Li Feng Dong
Keyword(s):  
Electron Microscopy ◽  
Nickel Catalyst ◽  
Carbon Fibers ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Chemical Vapor Deposition Method ◽  
Catalyst Precursor ◽  
X Ray ◽  
Transmission Electron

In this paper, we have synt hesized exotic carbon fibers with branched spurs by a chemical vapor deposition method using nickel catalyst precursor at 600 °C. No catalyst particles were found at the base of the carbon spurs, suggesting that the ni ckel catalyst particles, which were decomposed from the nickel catalyst precursor, facilitated the growth of the carbon fibers but not the spurs. The formation of the spurs resulted from the fluctuation of the carbon source gas acetylene flow. The samples were characterized by field emission sc anning electron microscopy, transmission electron microscopy, and X-ray powder diffraction.

Synthesis of MoS2 Nanoparticles with Inorganic Fullerene-Like Structure from Molybdenum Trioxide and Sulfur

2012 ◽  
Vol 554-556 ◽  
pp. 601-604
Author(s):  
Bin Gao ◽  
Xiao Jun Zhang
Keyword(s):  
Electron Microscopy ◽  
Molybdenum Trioxide ◽  
Raw Materials ◽  
Heating Temperature ◽  
Chemical Vapor ◽  
Diffraction Field ◽  
Chemical Vapor Deposition Method ◽  
X Ray ◽  
Inorganic Fullerene ◽  
Transmission Electron

MoS2 nanoparticles with fullerene-like (IF-MoS2) structure were successfully obtained at heating temperature higher than 840 °C by chemical vapor deposition method in a three-tube furnace using MoO3 and S (sulfur) powders as raw materials. The synthesized samples were characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, and energy dispersion X-ray spectrometerrespectively. IF-MoS2 nanoparticles can be obtained only in the narrow temperature range of 840 °C-870 °C, and the diameter of IF-MoS2 nanoparticles increases with temperature. A gradual formation mechanism of IF-MoS2 nanoparticles was discussed in detail.

Synthesis of Crystalline C3N4 films and the new C-N Phases

1996 ◽  
Vol 441 ◽  
Author(s):  
Yan Chen ◽  
D. J. Johnson ◽  
R. H. Prince ◽  
Liping Guo ◽  
E. G. Wang
Keyword(s):  
Electron Microscopy ◽  
Vapor Deposition ◽  
Growth Parameters ◽  
Chemical Vapor ◽  
Monoclinic Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lattice Constants ◽  
Transmission Electron ◽  
Hot Filament

AbstractCrystalline C-N films composed of α- and β-C3N4, as well as other C-N phases, have been synthesized via bias-assisted hot-filament chemical vapor deposition using a gas mixture of nitrogen and methane. Scanning electron microscopy(SEM), energy dispersive X-ray (EDX) analysis, X-ray diffraction (XRD) and transmission electron microscopy (TEM) were used to characterize the films. Lattice constants of the α- and β-C3N4 phases obtained coincide very well with the theoretical values. In addition to these phases, two new C-N phases in the films have been identified by TEM and XRD; one having a tetragonal structure with a = 5.65 Å, c = 2.75Å, and the second having a monoclinic structure with a = 5.065 Å, b= 11.5 Å, c = 2.801 Å and β = 96°. Their stoichiometric values and atomic arrangements have not yet been identified. Furthermore, variation in growth parameters, for example methane concentration, bias voltage, etc., can yield preferred growth of different C-N phases.

Synthesis and Cathodoluminescence of β-Ga2O3 Nanowires with Holes

2008 ◽  
Vol 8 (3) ◽  
pp. 1284-1287
Author(s):  
Xitian Zhang ◽  
Zhuang Liu ◽  
Suikong Hark
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Vapor Deposition ◽  
Gallium Oxide ◽  
Chemical Vapor ◽  
Oxide Nanowires ◽  
X Ray ◽  
Transmission Electron ◽  
Reactive Surfaces ◽  
Scanning Electron

Gallium oxide nanowires were synthesized on Si (001) substrate by chemical vapor deposition, using a Ga/Ga2O3 mixture as a precursor and Au as a catalyst. The structure of the as-synthesized products was examined by X-ray powder diffraction and high-resolution transmission electron microscopy, and found to be monoclinic β-Ga2O3. The morphologies of the β-Ga2O3 nanowires were characterized by scanning electron microscopy. The majority of the nanowires contain holes along their length, but a few were also found without holes. The holes are believed to be formed by the reaction of adsorbed Ga droplets on reactive terminating surfaces of the nanowires. For nanowires where these reactive surfaces are not exposed, the reaction of Ga is retarded. Cathodoluminescence (CL) of the nanowires was measured. Three emission bands centered at 376, 454, and 666 nm, respectively, were observed.

Preparation of Silica Nano-Rods by CVD

2008 ◽  
Vol 47-50 ◽  
pp. 359-362 ◽  
Author(s):  
Guang Zhu ◽  
Xiao Ping Zou ◽  
Jin Cheng ◽  
Mao Fa Wang ◽  
Yi Su
Keyword(s):  
Electron Microscopy ◽  
Deposition Temperature ◽  
Smooth Surface ◽  
Chemical Vapor ◽  
Chemical Vapor Deposition Method ◽  
Uniform Size ◽  
X Ray ◽  
Synthesis Conditions ◽  
Transmission Electron ◽  
Nano Rods

The straight silica nano-rods with a diameter of about 200nm and smooth surface were synthesized by chemical vapor deposition method at 1300°C. The as-synthesized samples were characterized by means of scanning electron microscopy, energy dispersive x-ray, and transmission electron microscopy. The results show that as-synthesized silica nano-rods have a uniform size, well-defined shape, and smooth surface. However, the morphologies and microstructures of silica nano-rods are affected by synthesis conditions, such as the concentration of the SiOx and the the deposition temperature. On the basis of these experimental results, a possible growth mechanism of silica nano-rods in this process is proposed.

SiGe Nanowires Grown by LPCVD: Morphological and Structural Analysis

2010 ◽  
Vol 1258 ◽  
Author(s):  
Andrés Rodríguez ◽  
Jesús Sangrador ◽  
Tomás Rodríguez ◽  
Carmen Ballesteros ◽  
Carmelo Prieto ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Vapor Liquid Solid ◽  
Chemical Vapor Deposition Reactor ◽  
X Ray ◽  
Transmission Electron ◽  
Pressure Chemical ◽  
Scanning Electron

AbstractSiGe nanowires were grown by the vapor-liquid-solid method using a low pressure chemical vapor deposition reactor and different flows of the GeH4 and Si2H6 gas precursors. The morphology of the nanowires was studied by field emission scanning electron microscopy, and the length, diameter and density of nanowires were determined. Their structure and crystallinity were analyzed by transmission electron microscopy and its related techniques. Energy dispersive X-ray emission of individual nanowires as well a Raman spectroscopy were used to determine their composition and to analyze its homogeneity.

scholarly journals Metal film deposition by laser breakdown chemical vapor deposition

1986 ◽  
Vol 1 (3) ◽  
pp. 420-424 ◽  
Author(s):  
T.R. Jervis ◽  
L.R. Newkirk
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Chemical Vapor Deposition ◽  
Gas Phase ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Film Deposition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

Dielectric breakdown of gas mixtures can be used to deposit thin films by chemical vapor deposition with appropriate control of flow and pressure conditions to suppress gas-phase nucleation and particle formation. Using a pulsed CO2 laser operating at 10.6 μ where there is no significant resonant absorption in any of the source gases, homogeneous films from several gas-phase precursors have been sucessfully deposited by gas-phase laser pyrolysis. Nickel and molybdenum from the respective carbonyls representing decomposition chemistry and tungsten from the hexafluoride representing reduction chemistry have been demonstrated. In each case the gas precursor is buffered with argon to reduce the partial pressure of the reactants and to induce breakdown. Films have been characterized by Auger electron spectroscopy, x-ray diffraction, transmission electron microscopy, pull tests, and resistivity measurements. The highest quality films have resulted from the nickel depositions. Detailed x-ray diffraction analysis of these films yields a very small domain size consistent with the low temperature of the substrate and the formation of metastable nickel carbide. Transmission electron microscopy supports this analysis.

Reduction of Structural Defects in Ge Epitaxially Grown on Nano-Structured Si Islands on SOI Substrate

2013 ◽  
Vol 205-206 ◽  
pp. 400-405
Author(s):  
Peter Zaumseil ◽  
Yuji Yamamoto ◽  
Markus Andreas Schubert ◽  
Thomas Schroeder ◽  
Bernd Tillack
Keyword(s):  
Electron Microscopy ◽  
Vapor Deposition ◽  
Strain State ◽  
Chemical Vapor ◽  
Structural Defects ◽  
Misfit Dislocations ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Nanostructured Si

One way to further increase performance and/or functionality of Si micro-and nanoelectronics is the integration of alternative semiconductors on silicon (Si). We studied the Ge/Si heterosystem with the aim to realize a Ge deposition free of misfit dislocations and with low content of other structural defects. Ge nanostructures were selectively grown by chemical vapor deposition on periodic Si nanoislands (dots and lines) on SOI substrate either directly or with a thin (about 10 nm) SiGe buffer layer. The strain state of the structures was measured by different laboratory-based x-ray diffraction techniques. It was found that a suited SiGe buffer improves the compliance of the Si compared to direct Ge deposition; plastic relaxation during growth can be prevented, and fully elastic relaxation of the structure can be achieved. Transmission electron microscopy confirms that the epitaxial growth of Ge on nanostructured Si is free of misfit dislocations.

scholarly journals Газофазный синтез нового функционального гибридного материала на основе многостенных углеродных нанотрубок, декорированных ограненными нанокристаллами алюминия

2018 ◽  
Vol 44 (19) ◽  
pp. 24
Author(s):  
К.В. Кремлев ◽  
А.М. Объедков ◽  
Н.М. Семенов ◽  
Б.С. Каверин ◽  
С.Ю. Кетков ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Vapor Deposition ◽  
Metalorganic Chemical Vapor Deposition ◽  
Chemical Vapor ◽  
Multiwalled Carbon ◽  
X Ray ◽  
Hybrid Nanomaterial ◽  
Transmission Electron ◽  
Aluminum Nanocrystals ◽  
First Time

AbstractThe deposition of polyhedral aluminum nanocrystals onto the surface of multiwalled carbon nanotubes (MWCNTs) via metalorganic chemical vapor deposition with the use of triisobutylaluminum as the precursor has been performed for the first time. The new hybrid nanomaterial (Al/MWCNTs) has been characterized by X-ray phase analysis, scanning electron microscopy, and high-resolution transmission electron microscopy. The obtained Al/MWCNTs hybrid materials were tested as the filler for the creation of threedimensional composites on the basis of an AMg2 alloy via powder metallurgy. It has been shown that the use of Al/MWCNTs as the filler increases the hardness of the composites by 18% in comparison with the initial MWCNTs.

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