scholarly journals Characterization of Sic Fibers by Soft X-Ray Photoelectron and Photoabsorption Spectroscopies and Scanning Auger Microscopy

1996 ◽  
Vol 437 ◽  
Author(s):  
Qing Ma ◽  
M. W. Mcdowell ◽  
R. A. Rosenberg
Keyword(s):  
Depth Profiling ◽  
Chemical Vapor ◽  
Layer Depth ◽  
X Ray ◽  
Sic Fibers ◽  
Line Shapes ◽  
Scanning Auger Microscopy ◽  
Auger Microscopy ◽  
Sic Coatings

AbstractSynchrotron radiation soft x-ray photoelectron and photoabsorption spectroscopy was used to characterize commercially obtained SiC fibers, which were produced by chemical vapor deposition (CVD) of SiC on a W core, followed by a carbon passivating layer. Depth profiling of the fiber through the carbon/SiC interface was done by making Si 2p and C ls core level PES and PAS, as well as scanning Auger microscopy, measurements following Ar+ sputtering. No significant changes in either photoemission or absorption or Auger line shapes were observed as a function of the depth, which indicates that there is no significant interfacial reaction. The line shapes of the carbonaceous coatings are predominately graphite-like and those of the CVD SiC coatings are microcrystalline, with presence of disorder to some extent in both cases.

Microstructural Characterization of Ba2YCu3O7 Films Produced by Co-Evaporation

1987 ◽  
Vol 99 ◽  
Author(s):  
G. J. Fisanick ◽  
P. Mankeewicht ◽  
W. Skocpolt ◽  
R. E. Howardt ◽  
A. Dayem ◽  
...  
Keyword(s):  
Plane Surface ◽  
Depth Profiling ◽  
Microstructural Characterization ◽  
Areal Density ◽  
Oxygen Stoichiometry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Annealing Conditions ◽  
Auger Microscopy

ABSTRACTBa2YCu3O7 films produced by co-evaporation of BaF2, Cu and Y onto <100> S1TiO3 substrates in an O2 ambient followed by post-annealing were analyzed using RBS, X-ray diffraction and Auger microscopy. These films exhibit Tc's (R=0) of =90K and a best Jc of > 1.0×106 A/cm2 at 81K for a =2500A thick film. RBS and Auger depth profiling limit the level of F present in the post-annealed films to <5 at. %, although F is evident in the as-deposited material. RBS channeling experiments yield a Xmin=31%, demonstrating the epitaxial quality of the films. X-ray diffraction shows that the films are predominantly oriented with c-axis perpendicular to the substrate, with narrow mosaic spread in-plane. A small portion of the film is in the form of needles oriented with a-axis perpendicular to the substrate, whose areal density is dependent on annealing conditions and local film stoichiometry. Scanning Auger microscopy confirms that the needles and c-axis plateaus have the same metal and oxygen stoichiometry. Also present in the film are insulating balls which appear to nucleate terraces in the c-axis perpendicular structure. Scanning Auger shows that these features are also close to the metals stoichiometry, but are C rich compared to the needles. The plateaus are covered with =11 times more C than the needles, indicating that the basal plane surface is highly reactive. Auger depth profiling and RBS show little evidence for interdiffusion.

New insights into the characterization of the electrode/electrolyte interfaces within LiMn2O4/Li4Ti5O12 cells, by X-ray photoelectron spectroscopy, scanning Auger microscopy and time-of-flight secondary ion mass spectrometry

2017 ◽  
Vol 5 (29) ◽  
pp. 15315-15325 ◽  
Author(s):  
Jean-Baptiste Gieu ◽  
Volker Winkler ◽  
Cécile Courrèges ◽  
Loubna El Ouatani ◽  
Cécile Tessier ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Photoelectron Spectroscopy ◽  
Secondary Ion Mass Spectrometry ◽  
Time Of Flight ◽  
X Ray ◽  
Scanning Auger Microscopy ◽  
Ion Mass Spectrometry ◽  
Auger Microscopy ◽  
Secondary Ion

This work aims to study the electrode/electrolyte interfaces in a Li4Ti5O12 (LTO)/LiMn2O4 (LMO) cell assembled with a VC-containing electrolyte and operating at 60 °C.

Growth of Single Crystalline ZnO Nanotubes and Nanosquids

2007 ◽  
Vol 1057 ◽  
Author(s):  
Abhishek Prasad ◽  
Samuel Mensah ◽  
Jiesheng Wang ◽  
Archana Pandey ◽  
Yoke Khin Yap
Keyword(s):  
Vapor Deposition ◽  
Self Assembly ◽  
Chemical Vapor ◽  
Zno Nanostructures ◽  
X Ray ◽  
Thermal Chemical Vapor Deposition ◽  
Crystal Growth Mechanism ◽  
Zno Nanotubes ◽  
Solid Crystal

ABSTRACTThe growth of ZnO nanotubes and nanosquids is obtained by conventional thermal chemical vapor deposition (CVD) without the use of catalysts or templates. Characterization of these ZnO nanostructures was conducted by X-ray powder diffraction (XRD), Field-emission scanning electron microscopy (FESEM), Raman spectroscopy, and photoluminescence (PL). Results indicate that these ZnO nanostructures maintain the crystalline structures of the bulk wurtzite ZnO crystals. Our results show that rapid cooling can be used to induce the formation of ZnO nanotubes and ZnO nanosquids. The self-assembly of these novel ZnO nanostructures are guided by the theory of nucleation and the vapor-solid crystal growth mechanism.

Deposition of TRISO Particles With Superhard SiC Coatings and the Characterization of Anisotropy by Raman Spectroscopy

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
E. López-Honorato ◽  
P. J. Meadows ◽  
J. Tan ◽  
Y. Xiang ◽  
P. Xiao
Keyword(s):  
Solid Solution ◽  
Raman Spectroscopy ◽  
Pyrolytic Carbon ◽  
X Ray Diffraction ◽  
X Ray ◽  
Flat Substrate ◽  
High Concentrations ◽  
Triso Particles ◽  
Sic Coatings

In this work we have deposited silicon carbide (SiC) at 1300°C with the addition of small amounts of propylene. The use of propylene and high concentrations of methyltrichlorosilane (9 vol %) allowed the deposition of superhard SiC coatings (42 GPa). The superhard SiC could result from the presence of a SiC–C solid solution, undetectable by X-ray diffraction but visible by Raman spectroscopy. Another sample obtained by the use of 50 vol % Argon, also showed the formation of SiC with good properties. The use of a flat substrate together with the particles showed the importance of carrying out the analysis on actual particles rather than in flat substrates. We show that it is possible to characterize the anisotropy of pyrolytic carbon by Raman spectroscopy.

AlxGa1-xN-Based Materials and Heterostructures

1996 ◽  
Vol 449 ◽  
Author(s):  
P. Kung ◽  
A. Saxler ◽  
D. Walker ◽  
X. Zhang ◽  
R. Lavado ◽  
...  
Keyword(s):  
Chemical Vapor ◽  
Bragg Reflectors ◽  
X Ray Diffraction ◽  
Chemical Vapor Deposition Growth ◽  
X Ray ◽  
Sapphire Substrates ◽  
Transmission Electron ◽  
Dimensional Electron Gas ◽  
P Type

ABSTRACTWe present the metalorganic chemical vapor deposition growth, n-type and p-type doping and characterization of AlxGa1-xN alloys on sapphire substrates. We report the fabrication of Bragg reflectors and the demonstration of two dimensional electron gas structures using AlxGa1-xN high quality films. We report the structural characterization of the AlxGa1-xN / GaN multilayer structures and superlattices through X-ray diffraction and transmission electron microscopy. A density of screw and mixed threading dislocations as low as 107 cm-2 was estimated in AlxGa1-xN / GaN structures. The realization of AlxGa1-xN based UV photodetectors with tailored cut-off wavelengths from 365 to 200 nm are presented.

Potentialities of an Innovative Technique Like 129Xe NMR and of Saxs for the Characterization of Microporous Sol-Gel Derived SiO2

1996 ◽  
Vol 431 ◽  
Author(s):  
L. C. de Menorval ◽  
A. Julbe ◽  
H. Jobic ◽  
J. A. Dalmon ◽  
C. Guizard
Keyword(s):  
Chemical Shifts ◽  
High Surface ◽  
Sol Gel ◽  
Narrow Pore Size Distribution ◽  
X Ray ◽  
Porous Texture ◽  
129Xe Nmr ◽  
Line Shapes ◽  
X Ray Scattering

AbstractAddition of surfactants in TEOS derived sols leads to micro- or mesoporous materials whose porous texture can be varied by changing the surfactant quantity and/or chain length. This series of materials, with a relatively narrow pore size distribution, is well adapted to study the potentialities of an innovative characterization technique like 129Xe Nuclear Magnetic Resonance in comparison with Small Angle X-ray Scattering and N2 adsorption. SAXS revealed a high surface rugosity of the materials and a good correlation with pore hydraulic radius distributions measured by N2 adsorption. Using 129Xe NMR, we have studied the Xe chemical shifts (δXe,) as a function of pXe, and have pointed out several original results showing the importance, for microporous materials, of the NMR line shapes and of the slope of the lines δXe.=f(pXe).

CVD Boron Carbo-Nitride as Pore Sealant for Ultra Low-K Interlayer Dielectrics

2005 ◽  
Vol 863 ◽  
Author(s):  
P. Ryan Fitzpatrick ◽  
Sri Satyanarayana ◽  
Yangming Sun ◽  
John M. White ◽  
John G. Ekerdt
Keyword(s):  
Photoelectron Spectroscopy ◽  
Depth Profiling ◽  
Chemical Vapor ◽  
K Value ◽  
X Ray ◽  
Dimethylamine Borane ◽  
The Stability ◽  
Low K ◽  
Secondary Ion ◽  
Sims Depth Profiling

AbstractBlanket porous methyl silsesquioxane (pMSQ) films on a Si substrate were studied with the intent to seal the pores and prevent penetration of a metallic precursor during barrier deposition. The blanket pMSQ films studied were approximately 220 nm thick and had been etched and ashed. When tantalum pentafluoride (TaF5) is exposed to an unsealed pMSQ sample, X-ray photoelectron spectroscopy (XPS) depth profiling and secondary ion mass spectroscopy (SIMS) depth profiling reveal penetration of Ta into the pores all the way to the pMSQ / Si interface. Boron carbo-nitride films were grown by thermal chemical vapor deposition (CVD) using dimethylamine borane (DMAB) precursor with Ar carrier gas and C2H4 coreactant. These films had a stoichiometry of BC0.9N0.07 and have been shown in a previous study to have a k value as low as 3.8. BC0.9N0.07 films ranging from 1.8 to 40.6 nm were deposited on pMSQ and then exposed to TaF5 gas to determine the extent of Ta penetration into the pMSQ. Ta penetration was determined by XPS depth profiling and sometimes SIMS depth profiling. XPS depth profiling of a TaF5 / 6.3 nm BC0.9N0.07 / pMSQ / Si film stack indicates the attenuation of the Ta signal to < 2 at. % throughout the pMSQ. Backside SIMS of this sample suggests that trace amounts of Ta (< 2 at. %) are due to knock-in by Ar ions used for sputtering. An identical film stack containing 3.9 nm BC0.9N0.07 was also successful at inhibiting Ta penetration even with a 370°C post-TaF5 exposure anneal, suggesting the stability of BC0.9N0.07 to thermal diffusion of Ta. All BC0.9N0.07 films thicker than and including 3.9 nm prevented Ta from penetrating into the pMSQ.

scholarly journals AACVD Synthesis and Characterization of Iron and Copper Oxides Modified ZnO Structured Films

Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 471 ◽  
Author(s):  
Martha Claros ◽  
Milena Setka ◽  
Yecid P. Jimenez ◽  
Stella Vallejos
Keyword(s):  
Contact Angle ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Contact Angles ◽  
Copper Oxides ◽  
Water Contact ◽  
X Ray ◽  
Hydrophobic Behavior

Non-modified (ZnO) and modified (Fe2O3@ZnO and CuO@ZnO) structured films are deposited via aerosol assisted chemical vapor deposition. The surface modification of ZnO with iron or copper oxides is achieved in a second aerosol assisted chemical vapor deposition step and the characterization of morphology, structure, and surface of these new structured films is discussed. X-ray photoelectron spectrometry and X-ray diffraction corroborate the formation of ZnO, Fe2O3, and CuO and the electron microscopy images show the morphological and crystalline characteristics of these structured films. Static water contact angle measurements for these structured films indicate hydrophobic behavior with the modified structures showing higher contact angles compared to the non-modified films. Overall, results show that the modification of ZnO with iron or copper oxides enhances the hydrophobic behavior of the surface, increasing the contact angle of the water drops at the non-modified ZnO structures from 122° to 135° and 145° for Fe2O3@ZnO and CuO@ZnO, respectively. This is attributed to the different surface properties of the films including the morphology and chemical composition.

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