Characterization of lubricated states on carbon coated media by low energy photoelectron spectroscopy method in ambient atmosphere

1991 ◽  
Vol 69 (12) ◽  
pp. 8042-8046 ◽  
Author(s):  
Ken‐ichi Nishimori ◽  
Kohichi Tanaka ◽  
Yasunobu Inoue
Keyword(s):  
Photoelectron Spectroscopy ◽  
Low Energy ◽  
Spectroscopy Method ◽  
Ambient Atmosphere ◽  
Carbon Coated

Monitoring and characterization of creation of geopolymers prepared from fly ash and metakaolin by X-ray photoelectron spectroscopy method

2014 ◽  
Vol 34 (3) ◽  
pp. 841-849 ◽  
Author(s):  
M. Kanuchova ◽  
L. Kozakova ◽  
M. Drabova ◽  
M. Sisol ◽  
A. Estokova ◽  
...  
Keyword(s):  
Fly Ash ◽  
Photoelectron Spectroscopy ◽  
Spectroscopy Method ◽  
X Ray

Functionalization of LiFePO4/C by Spontaneous Reduction of In-situ Generated Bromobenzene Diazonium Ions in Organic Media

2015 ◽  
Vol 1773 ◽  
pp. 21-26
Author(s):  
Nicolas Delaporte ◽  
Karim Zaghib ◽  
Daniel Bélanger
Keyword(s):  
Photoelectron Spectroscopy ◽  
Organic Media ◽  
Agglomerate Size ◽  
X Ray ◽  
Organic Species ◽  
Spontaneous Reduction ◽  
Diazonium Ions ◽  
Carbon Coated

ABSTRACTBromophenyl moieties were attached to the carbon-coated LiFePO4 (LiFePO4/C) surface by spontaneous reduction of in-situ generated 4-bromobenzene diazonium ions in organic media. The presence of the surface organic species on the grafted LiFePO4/C powders was confirmed by X-ray photoelectron spectroscopy. Thermogravimetric analyses revealed a low loading (lower than 1 wt. %) of grafted molecules. The electrochemical characterization of the LiFePO4/C cathodes showed that a low loading of bromophenyl groups at the LiFePO4/C surface can enhance the rate of Li+ extraction, presumably due to the decrease of the LiFePO4/C agglomerate size and an increase of the wettability of the electrode. On the other hand, poor performances were obtained using the grafted cathode material with the highest loading of bromophenyl moieties.

Atomic force microscopy and X-ray photoelectron spectroscopy characterization of low-energy ion sputtered mica

2007 ◽  
Vol 601 (13) ◽  
pp. 2735-2739 ◽  
Author(s):  
Renato Buzio ◽  
Andrea Toma ◽  
Andrea Chincarini ◽  
Francesco Buatier de Mongeot ◽  
Corrado Boragno ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Photoelectron Spectroscopy ◽  
Low Energy ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force

Growth and Characterization of Epitaxial Graphene on SiC Induced by Carbon Evaporation

2010 ◽  
Vol 645-648 ◽  
pp. 593-596
Author(s):  
Ameer Al-Temimy ◽  
Christian Riedl ◽  
Ulrich Starke
Keyword(s):  
Photoelectron Spectroscopy ◽  
Epitaxial Graphene ◽  
Low Energy ◽  
Ultraviolet Photoelectron Spectroscopy ◽  
Force Microscopy ◽  
Low Energy Electron Diffraction ◽  
Atomic Force ◽  
Graphene Lattice ◽  
Low Energy Electron

By carbon evaporation under ultrahigh vacuum (UHV) conditions, epitaxial graphene can be grown on SiC(0001) at significantly lower temperatures than with conventional Si sublimation. Therefore, the degradation of the initial SiC surface morphology can be avoided. The layers of graphene are characterized by low energy electron diffraction (LEED), angle resolved ultraviolet photoelectron spectroscopy (ARUPS), and atomic force microscopy (AFM). On SiC the graphene lattice is rotated by 30o in comparison to preparation by annealing in UHV alone.

Cryomicroscopy of multiphase latices

1991 ◽  
Vol 49 ◽  
pp. 1060-1061
Author(s):  
O. L. Shaffer ◽  
M.S. El-Aasser ◽  
C. L. Zhao ◽  
M. A. Winnik ◽  
R. R. Shivers
Keyword(s):  
Electron Microscopy ◽  
Radiation Damage ◽  
Freeze Fracture ◽  
Particle Morphology ◽  
Second Stage ◽  
Transmission Electron ◽  
Important Approach ◽  
Carbon Coated ◽  
Preparation Techniques

Transmission electron microscopy is an important approach to the characterization of the morphology of multiphase latices. Various sample preparation techniques have been applied to multiphase latices such as OsO4, RuO4 and CsOH stains to distinguish the polymer phases or domains. Radiation damage by an electron beam of latices imbedded in ice has also been used as a technique to study particle morphology. Further studies have been developed in the use of freeze-fracture and the effect of differential radiation damage at liquid nitrogen temperatures of the latex particles embedded in ice and not embedded.Two different series of two-stage latices were prepared with (1) a poly(methyl methacrylate) (PMMA) seed and poly(styrene) (PS) second stage; (2) a PS seed and PMMA second stage. Both series have varying amounts of second-stage monomer which was added to the seed latex semicontinuously. A drop of diluted latex was placed on a 200-mesh Formvar-carbon coated copper grid.

Characterization of interfaces in CVD-coated nicalon fiber-reinforced SiC

1989 ◽  
Vol 47 ◽  
pp. 556-557
Author(s):  
K.L. More ◽  
R.A. Lowden
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Chemical Vapor ◽  
Chemical Vapor Infiltration ◽  
Frictional Stress ◽  
Fiber Reinforced ◽  
Pull Out ◽  
Carbon Coated ◽  
Fiber Matrix

The mechanical properties of fiber-reinforced composites are directly related to the nature of the fiber-matrix bond. Fracture toughness is improved when debonding, crack deflection, and fiber pull-out occur which in turn depend on a weak interfacial bond. The interfacial characteristics of fiber-reinforced ceramics can be altered by applying thin coatings to the fibers prior to composite fabrication. In a previous study, Lowden and co-workers coated Nicalon fibers (Nippon Carbon Company) with silicon and carbon prior to chemical vapor infiltration with SiC and determined the influence of interfacial frictional stress on fracture phenomena. They found that the silicon-coated Nicalon fiber-reinforced SiC had low flexure strengths and brittle fracture whereas the composites containing carbon coated fibers exhibited improved strength and fracture toughness. In this study, coatings of boron or BN were applied to Nicalon fibers via chemical vapor deposition (CVD) and the fibers were subsequently incorporated in a SiC matrix. The fiber-matrix interfaces were characterized using transmission and scanning electron microscopy (TEM and SEM). Mechanical properties were determined and compared to those obtained for uncoated Nicalon fiber-reinforced SiC.

Characterization and Elimination of Forward Snapback Defects in GaAs Light Emitting Diodes

1996 ◽  
Author(s):  
J. Zimmer ◽  
D. Nielsen ◽  
T.A. Anderson ◽  
M. Schade ◽  
N. Saha ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Light Emitting Diode ◽  
Elevated Concentration ◽  
Forward Voltage ◽  
Light Emitting ◽  
Intermittent Yield ◽  
Si Doped ◽  
Secondary Ion ◽  
Furnace Pressure

Abstract The p-n junction of a GaAs light emitting diode is fabricated using liquid phase epitaxy (LPE). The junction is grown on a Si doped (~1018/cm3) GaAs substrate. Intermittent yield loss due to forward voltage snapback was observed. Historically, out of specification forward voltage (Vf) parameters have been correlated to abnormalities in the junction formation. Scanning electron (SEM) and optical microscopy of cleaved and stained samples revealed a continuous layer of material approximately 2.5 to 3.0 urn thick at the n-epi/substrate interface. Characterization of a defective wafer via secondary ion mass spectroscopy (SIMS) revealed an elevated concentration of O throughout the region containing the defect. X-ray Photoelectron Spectroscopy (XPS) and Auger Electron Spectroscopy (AES) data taken from a wafer prior to growth of the epi layers did not reveal any unusual oxidation or contamination. Extensive review of the processing data suggested LPE furnace pressure was the obvious source of variability. Processing wafers through the LPE furnace with a slight positive H2 gas pressure has greatly reduced the occurrence of this defect.

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