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 OF HIGH QUALITY CRYSTALLINE C-N FILMS ON SILICON

1996 ◽  
Vol 10 (12) ◽  
pp. 567-571 ◽  
Author(s):  
YAN CHEN ◽  
E.G. WANG ◽  
FENG CHEN ◽  
LIPING GUO
Keyword(s):  
Electron Microscopy ◽  
Vapor Deposition ◽  
Interfacial Layer ◽  
Chemical Vapor ◽  
X Ray Diffraction ◽  
High Quality ◽  
X Ray ◽  
Transmission Electron ◽  
Hot Filament ◽  
Microscopy Images

High quality crystalline C–N films have been synthesized via hot filament chemical vapor deposition using a gas mixture of nitrogen and methane. Scanning electron microscopy images show that a high density of crystalline clusters has been achieved. The clusters are composed of small columnar crystals (20–200 nm across) with hexagonal facets. Energy dispersive X ray analysis indicates a relative nitrogen:carbon composition of 1.30–2.5. X ray diffraction results indicate the films composed of β- and α- C 3 N 4 phases. Together with transmission electron microscopy analyses, we suggest that an interfacial layer C 3−x Si x N 4 is formed between the silicon substrate and the crystalline carbonnitride films.

Understanding the Growth Mechanisms of Tin Oxide Nanowires by Chemical Vapor Deposition

2021 ◽  
Vol 21 (4) ◽  
pp. 2538-2544
Author(s):  
Nguyen Minh Hieu ◽  
Nguyen Hoang Hai ◽  
Mai Anh Tuan
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Chemical Mapping ◽  
X Ray Diffraction ◽  
Lattice Constants ◽  
Transmission Electron ◽  
Scanning Transmission

Tin oxides nanowires were prepared by chemical vapor deposition using shadow mask. X-ray diffraction indicated that the products were tetragonal having crystalline structure with lattice constants a = 0.474 nm and c = 0.318 nm. The high-resolution transmission electron microscopy revealed that inter planar spacing is 0.25 nm. The results chemical mapping in scanning transmission electron microscopy so that the two elements of Oxygen and Tin are distributed very homogeneously in nanowires and exhibit no apparent elements separation. A bottom-up mechanism for SnO2 growth process has been proposed to explain the morphology of SnO2 nanowires.

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.

Polymorphous silicon nanowires synthesized by plasma-enhanced chemical vapor deposition

2002 ◽  
Vol 737 ◽  
Author(s):  
X.B. Zeng ◽  
X.B. Liao ◽  
H.W. Diao ◽  
Z.H. Hu ◽  
Y.Y. Xu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Chemical Vapor Deposition ◽  
Silicon Nanowires ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
The Body ◽  
Si Nanowires ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

ABSTRACTPolymorphous Si nanowires (SiNWS) have been successfully synthesized on Si wafer by plasma enhanced chemical vapor deposition (PECVD) at 440°C, using silane as the Si source and Au as the catalyst. To grow the polymorphous SiNWS preannealing the Si substrate with Au film at 1100 °C is needed. The diameters of Si nanowires range from 15 to 100 nm. The structure, morphology and chemical composition of the SiNWS have been characterized by high resolution x-ray diffraction, scanning electron microscopy, transmission electron microscopy, as well as energy dispersive x-ray spectroscopy. A few interesting nanowires with Au nanoclusters uniformly distributed in the body of the wire were also produced by this technique.

Synthesis of Carbon Onions with High Purity by Chemical Vapor Deposition

2013 ◽  
Vol 641-642 ◽  
pp. 43-46
Author(s):  
Lei Shan Chen ◽  
Cun Jing Wang
Keyword(s):  
Electron Microscopy ◽  
Vapor Deposition ◽  
Carbon Materials ◽  
Catalyst Support ◽  
Chemical Vapor ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Carbon Onions ◽  
Nano Carbon

Nano-carbon materials were synthesized by decomposing acetylene at 400 °C using iron supported on alumina as catalyst. The catalysts contain about 0.3 and 5.2 wt% iron. The products were refluxed in concentrated HCl at 80°C for 36 h in order to remove the catalyst support. The samples were examined by transmission electron microscopy and X-ray diffraction. The results show that carbon onions surrounding Fe3C core were obtained using the catalyst containing 0.3 wt% iron and these carbon onions had a structure of stacked graphitic fragments, with diameters in the range 15-50 nm.

scholarly journals Ferromagnetic Property and Synthesis of Onion-Like Fullerenes by Chemical Vapor Deposition Using Fe and Co Catalysts Supported on NaCl

2011 ◽  
Vol 2011 ◽  
pp. 1-6
Author(s):  
Yongzhen Yang ◽  
Xuguang Liu ◽  
Yanxing Han ◽  
Wenfang Ren ◽  
Bingshe Xu
Keyword(s):  
Electron Microscopy ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
X Ray Diffraction ◽  
Ferromagnetic Property ◽  
X Ray ◽  
Co Catalysts ◽  
Transmission Electron ◽  
Morphology And Structure ◽  
Co Nanoparticles

Metal-encapsulating onion-like fullerenes (M@OLFs) were synthesized by CVD at relatively low temperature (420C∘) using Fe and Co nanoparticles impregnated into NaCl as catalyst. The morphology and structure of the products were characterized by field emission scanning electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction, and Raman spectroscopy. The results show that Fe@OLFs and Co@OLFs with stacked graphitic fragments were prepared using Fe/NaCl or Co/NaCl as catalysts; after Co@OLFs were immersed in concentrated HCl for 48 hours, Co nanoparticles encapsulated by carbon shells were not removed, meaning that carbon shells can protect the encapsulated Co cores against environmental degradation. The coercivity value (750.23 Oe) of Co@OLFs showed an obvious magnetic property.

Growth and Characterization of Tungsten Oxide for Applications in Nanoelectronics

2006 ◽  
Vol 48 ◽  
pp. 113-118
Author(s):  
Karthikk Sridharan ◽  
Kenneth P. Roberts ◽  
Saibal Mitra
Keyword(s):  
Tungsten Oxide ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
X Ray Diffraction ◽  
Tungsten Filament ◽  
X Ray ◽  
Transmission Electron ◽  
Oxide Nanorods ◽  
Hot Filament

Tungsten oxide nanorods were prepared in a hot filament chemical vapor deposition (HFCVD) reactor. A mixture of gases containing hydrogen, oxygen or hydrogen and methane mixed with water vapor were passed into a quartz glass jar reactor and activated using a heated tungsten filament. The resulting deposits were characterized by transmission electron microscopy (TEM), x-ray diffraction (XRD), and Raman Spectroscopy. The deposit consisted of tungsten oxide nanorods (5 – 10 nm diameter and 50 – 75 nm long) and tungsten nanospheres with diameters of ~50nm. The tungsten oxide is then reduced to metallic tungsten by annealing in a hydrogen environment.

OMCVD of thin films from metal diketonates and triphenylbismuth

1990 ◽  
Vol 5 (6) ◽  
pp. 1169-1175 ◽  
Author(s):  
A. D. Berry ◽  
R. T. Holm ◽  
M. Fatemi ◽  
D. K. Gaskill
Keyword(s):  
Electron Microscopy ◽  
Vapor Deposition ◽  
Atmospheric Pressure ◽  
Electron Spectroscopy ◽  
Auger Electron ◽  
Chemical Vapor ◽  
X Ray Diffraction ◽  
Strontium Barium ◽  
X Ray ◽  
Scanning Electron

Films containing the metals copper, yttrium, calcium, strontium, barium, and bismuth were grown by organometallic chemical vapor deposition (OMCVD). Depositions were carried out at atmospheric pressure in an oxygen-rich environment using metal beta-diketonates and triphenylbismuth. The films were characterized by Auger electron spectroscopy, Nomarski and scanning electron microscopy, and x-ray diffraction. The results show that films containing yttrium consisted of Y2O3 with a small amount of carbidic carbon, those with copper and bismuth were mixtures of oxides with no detectable carbon, and those with calcium, strontium, and barium contained carbonates. Use of a partially fluorinated barium beta-diketonate gave films of BaF2 with small amounts of BaCO3.

scholarly journals Growth of U-Shaped Graphene Domains on Copper Foil by Chemical Vapor Deposition

Materials ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 1887
Author(s):  
Ming Pan ◽  
Chen Wang ◽  
Hua-Fei Li ◽  
Ning Xie ◽  
Ping Wu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Growth Parameters ◽  
Copper Substrate ◽  
Chemical Vapor ◽  
Morphology Evolution ◽  
Force Microscopy ◽  
Smooth Edge ◽  
Transmission Electron

U-shaped graphene domains have been prepared on a copper substrate by chemical vapor deposition (CVD), which can be precisely tuned for the shape of graphene domains by optimizing the growth parameters. The U-shaped graphene is characterized by using scanning electron microscopy (SEM), atomic force microscopy (AFM), transmission electron microscopy (TEM), and Raman. These show that the U-shaped graphene has a smooth edge, which is beneficial to the seamless stitching of adjacent graphene domains. We also studied the morphology evolution of graphene by varying the flow rate of hydrogen. These findings are more conducive to the study of morphology evolution, nucleation, and growth of graphene domains on the copper substrate.

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