Carbon Nanotubes Grown on Metallic Wires by Cold Plasma Technique

2002 ◽  
Vol 737 ◽  
Author(s):  
D. Sarangi ◽  
A. Karimi
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Growth Conditions ◽  
Effect Of Temperature ◽  
Rutherford Back Scattering ◽  
Novel Approach ◽  
Transmission Electron ◽  
Back Scattering ◽  
Metallic Wires ◽  
Metal Wires

ABSTRACTCarbon nanotubes on metallic wires may be act as electrode for the field emission (FE) luminescent devices. Growing nanotubes on metallic wires with controlled density, length and alignment are challenging issues for this kind of devices. We, in the present investigation grow carbon nanotubes directly on the metal wires by a powerful but simple technique. A novel approach has been proposed to align nanotubes during growth. Methane, acetylene and dimethylamine have been used as source gases. With the same growth conditions (viz. pressure, growth temperature and plasma) methane does not produce any nanotube but nanotubes grown with dimethylamine show shorter length and radius than acetylene. The effect of temperature to control the radius, time to control the density, plasma conditions to align the nanotubes has been focused. Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Rutherford Back Scattering (RBS) are used to characterize the nanotubes.

Synthesis and Photoluminescence of Y2O3:RE3+ (RE = Eu, Tb, Dy) Porous Nanotubes Templated by Carbon Nanotubes

2006 ◽  
Vol 6 (1) ◽  
pp. 120-124 ◽  
Author(s):  
Guixia Liu ◽  
Guangyan Hong
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Rare Earth Ions ◽  
Cubic Phase ◽  
Novel Approach ◽  
Transmission Electron ◽  
Characteristic Emission ◽  
Xrd Patterns ◽  
Photoluminescence Studies ◽  
Micrometer Scale

Y2O3:RE3+ (RE = Eu, Tb, Dy) porous nanotubes were first synthesized using carbon nanotubes as template. The morphology of the coated precursors and porous Y2O3:Eu3+ nanotubes was determined by scanning electron Microscopy (SEM) and transmission electron microscopy (TEM). It was found that the coating of precursors on carbon nanotubes (CNTs) is continuous and the thickness is about 15 nm, after calcinated, the Y2O3:Eu3+ nanotubes are porous with the diameter size in the range of 50–80 nm and the length in micrometer scale. X-ray diffraction (XRD) patterns confirmed that the samples are cubic phase Y2O3 and the photoluminescence studies showed that the porous rare earth ions doped nanotubes possess characteristic emission of Eu3+, Tb3+, and Dy3+. This method may also provide a novel approach to produce other inorganic porous nanotubes used in catalyst and sensors.

Effect of growth conditions on B-doped carbon nanotubes

2006 ◽  
Vol 21 (12) ◽  
pp. 3058-3064 ◽  
Author(s):  
Sara M.C. Vieira ◽  
Odile Stéphan ◽  
David L. Carroll
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Arc Discharge ◽  
Amorphous Material ◽  
Graphite Powder ◽  
Growth Conditions ◽  
Multiwalled Carbon ◽  
Boron Doped ◽  
Transmission Electron ◽  
Electron Energy Loss

The modified arc-discharge technique was used for the growth of boron-doped multiwalled carbon nanotubes. A variety of weight percentages of boron and sulfur were mixed (0.5–15 wt%) with graphite powder and packed in the consumable anode. Transmission electron microscopy, Raman spectroscopy, thermogravimetric analysis (TGA), and electron energy loss spectroscopy (EELS) were used to characterize the samples. EELS indicated a small percentage of boron present (<1 at.%) in the nanotubes. Sulfur was used primarily to enhance boron incorporation; however, Raman and TGA measurements indicated fewer defects and/or amorphous material present when sulfur was added.

Nucleation of Disorder in Fe3Al Alloys

1967 ◽  
Vol 25 ◽  
pp. 312-313
Author(s):  
P. R. Swann ◽  
W. R. Duff ◽  
R. M. Fisher
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Annealing Temperature ◽  
Antiphase Domain ◽  
Effect Of Temperature ◽  
Domain Structures ◽  
Transmission Electron ◽  
Domain Boundaries ◽  
Higher Temperature ◽  
The One

Recently we have investigated the phase equilibria and antiphase domain structures of Fe-Al alloys containing from 18 to 50 at.% Al by transmission electron microscopy and Mössbauer techniques. This study has revealed that none of the published phase diagrams are correct, although the one proposed by Rimlinger agrees most closely with our results to be published separately. In this paper observations by transmission electron microscopy relating to the nucleation of disorder in Fe-24% Al will be described. Figure 1 shows the structure after heating this alloy to 776.6°C and quenching. The white areas are B2 micro-domains corresponding to regions of disorder which form at the annealing temperature and re-order during the quench. By examining specimens heated in a temperature gradient of 2°C/cm it is possible to determine the effect of temperature on the disordering reaction very precisely. It was found that disorder begins at existing antiphase domain boundaries but that at a slightly higher temperature (1°C) it also occurs by homogeneous nucleation within the domains. A small (∼ .01°C) further increase in temperature caused these micro-domains to completely fill the specimen.

Defect morphology in thick relaxed layers of InGaAs on GaAs

1990 ◽  
Vol 48 (4) ◽  
pp. 668-669
Author(s):  
R H Dixon ◽  
P Kidd ◽  
P J Goodhew
Keyword(s):  
Electron Microscopy ◽  
Surface Morphology ◽  
Growth Conditions ◽  
X Ray Diffraction ◽  
Double Crystal ◽  
Strained Layers ◽  
Good Surface ◽  
Transmission Electron ◽  
Device Structures ◽  
Surface Morphologies

Thick relaxed InGaAs layers grown epitaxially on GaAs are potentially useful substrates for growing high indium percentage strained layers. It is important that these relaxed layers are defect free and have a good surface morphology for the subsequent growth of device structures.3μm relaxed layers of InxGa1-xAs were grown on semi - insulating GaAs substrates by Molecular Beam Epitaxy (MBE), where the indium composition ranged from x=0.1 to 1.0. The interface, bulk and surface of the layers have been examined in planar view and cross-section by Transmission Electron Microscopy (TEM). The surface morphologies have been characterised by Scanning Electron Microscopy (SEM), and the bulk lattice perfection of the layers assessed using Double Crystal X-ray Diffraction (DCXRD).The surface morphology has been found to correlate with the growth conditions, with the type of defects grown-in to the layer (e.g. stacking faults, microtwins), and with the nature and density of dislocations in the interface.

CHARACTERIZATION AND ELECTRICAL PROPERTIES OF ALIGNED CARBON NANOTUBES WITH HIGH ASPECT RATIO

2011 ◽  
Vol 10 (01n02) ◽  
pp. 23-28
Author(s):  
RAVI BHATIA ◽  
V. PRASAD ◽  
M. REGHU
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Aspect Ratio ◽  
Multiwall Carbon Nanotubes ◽  
High Quality ◽  
Transmission Electron Microscopy Analysis ◽  
Transmission Electron ◽  
Electron Microscopy Analysis ◽  
High Degree

High-quality multiwall carbon nanotubes (MWNTs) were produced by a simple one-step technique. The production of MWNTs was based on thermal decomposition of the mixture of a liquid phase organic compound and ferrocene. High degree of alignment was noticed by scanning electron microscopy. The aspect ratio of as-synthesized MWNTs was quite high (more than 4500). Transmission electron microscopy analysis showed the presence of the catalytic iron nanorods at various lengths of MWNTs. Raman spectroscopy was used to know the quality of MWNTs. The ratio of intensity of the G-peak to the D-peak was very high which revealed high quality of MWNTs. Magnetotransport studies were carried out at low temperature and a negative MR was noticed.

scholarly journals Biocompatibility Characteristics of Titanium Coated with Multi Walled Carbon Nanotubes—Hydroxyapatite Nanocomposites

Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 224 ◽  
Author(s):  
Jung-Eun Park ◽  
Yong-Seok Jang ◽  
Tae-Sung Bae ◽  
Min-Ho Lee
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Sol Gel ◽  
Pure Titanium ◽  
Cell Proliferation And Differentiation ◽  
Transmission Electron ◽  
Proliferation And Differentiation ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Multi walled carbon nanotubes-hydroxyapatite (MWCNTs-HA) with various contents of MWCNTs was synthesized using the sol-gel method. MWCNTs-HA composites were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). HA particles were generated on the surface of MWCNT. Produced MWCNTs-HA nanocomposites were coated on pure titanium (PT). Characteristic of the titanium coated MWCNTs-HA was evaluated by field-emission scanning electron microscopy (FE-SEM) and XRD. The results show that the titanium surface was covered with MWCNTs-HA nanoparticles and MWCNTs help form the crystalized hydroxyapatite. Furthermore, the MWCNTs-HA coated titanium was investigated for in vitro cellular responses. Cell proliferation and differentiation were improved on the surface of MWCNT-HA coated titanium.

Microstructural study of GaAs epitaxial layers on Ge(100) substrates

1995 ◽  
Vol 10 (4) ◽  
pp. 843-852 ◽  
Author(s):  
N. Guelton ◽  
R.G. Saint-Jacques ◽  
G. Lalande ◽  
J-P. Dodelet
Keyword(s):  
Electron Microscopy ◽  
Surface Preparation ◽  
Growth Conditions ◽  
Vapor Transport ◽  
Threading Dislocations ◽  
Misfit Dislocations ◽  
Antiphase Boundaries ◽  
Microstructural Study ◽  
Mismatch Strain ◽  
Transmission Electron

GaAs layers grown by close-spaced vapor transport on (100) Ge substrates have been investigated as a function of the experimental growth conditions. The effects on the microstructure of the surface preparation, substrate misorientation, and annealing were studied using optical microscopy and transmission electron microscopy. Microtwins and threading dislocations are suppressed by oxide desorption before deposition. Single domain GaAs layers have been obtained using a 50 nm thick double domain buffer layer on an annealed Ge substrate misoriented 3°toward [011]. The mismatch strain is mainly accommodated by dissociated 60°dislocations. These misfit dislocations extend along the interface by the glide of the threading dislocations inherited from the substrate, but strong interaction with antiphase boundaries (APB's) prevents them from reaching the interface. These results are discussed and compared with previous reports of GaAs growth on Ge(100).

Formation of Nanotubes of Carbon by Joule Heating of Carbon-Contaminated Si Nanochains

2011 ◽  
Vol 470 ◽  
pp. 171-174
Author(s):  
Hideo Kohno ◽  
Takafumi Nogami
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Transmission Electron Microscopy ◽  
Joule Heating ◽  
Carbon Shell ◽  
Surface Carbon ◽  
Si Nanowire ◽  
Transmission Electron

We report a new route to fabricating carbon nanotubes and nanotube interconnects. Insulating Si nanochains covered with hydrocarbon, which are a kind of Si nanowire, can be transformed into distorted nanotubes of carbon by Joule heating. Transmission electron microscopy observations of the transformation reveal that first a surface carbon shell is formed, and then oxide evaporates by Joule heating forming a nanotube.

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