EFFECT OF SURFACE CHARGING ON THE EROSION RATE OF POLYIMIDE UNDER 5 EV ATOMIC OXYGEN BEAM EXPOSURE

2006 ◽  
pp. 51-59
Author(s):  
MASAHITO TAGAWA ◽  
SHINSUKE SEIKYU ◽  
KEN-ICHI MAEDA ◽  
KUMIKO YOKOTA ◽  
NOBUO OHMAE
Keyword(s):  
Erosion Rate ◽  
Atomic Oxygen ◽  
Surface Charging ◽  
Effect Of Surface

Charge induced Variation of the Magnetization in Nanoporous Ni-Pd

2005 ◽  
Vol 876 ◽  
Author(s):  
Christian Lemier ◽  
Sadhan Ghosh ◽  
R. N. Viswanath ◽  
Guang-Tao Fei ◽  
Jörg Weissmüller
Keyword(s):  
Space Charge ◽  
High Surface ◽  
Volume Ratio ◽  
X Ray Diffraction ◽  
Noticeable Effect ◽  
Surface Charging ◽  
Nanoporous Metal ◽  
Nanoporous Metals ◽  
Effect Of Surface ◽  
Considerable Strain

AbstractChanges in the electronic structure in superficial space-charge regions may substantially affect the properties of metals near their surface. In materials with a nanoscale porosity and with a high surface to volume ratio, changes in the properties of even a thin surface layer may have a noticeable effect on the properties of the entire material. In nanoporous metals immersed in an electrolyte, the space charge can be induced as a part of the electric double layer at the metal-electrolyte interface. Here we present first experiments on the effect of surface charging in a nanoporous metal on the magnetism. We report reversible changes in the magnetic moment in Ni-Pd alloys. As possible origins of the dependency of the magnetization on the surface charge density we discuss band filling and, alternatively, magnetostriction. X-ray diffraction and dilatometry reveal a considerable strain amplitude, about of 6×10-4, resulting from surface charging; this corresponds to a surface-induced pressure in the crystal lattice, in the order of 0.3 GPa.

scholarly journals Effect of Surface treatment of Glass Fiber on Erosion damage of Frp

1997 ◽  
Vol 6 (5) ◽  
pp. 096369359700600 ◽  
Author(s):  
Dong-Seop Kim ◽  
Masatoshi Kubouchi ◽  
Ken Tsuda
Keyword(s):  
Surface Treatment ◽  
Glass Fiber ◽  
Erosion Rate ◽  
Fracture Behavior ◽  
Interface Strength ◽  
Coupling Agents ◽  
Erosion Damage ◽  
Sand Erosion ◽  
Effect Of Surface

The effect of surface treatment of glass fiber on sand erosion of FRP have studied with using three kinds of coupling agents. The erosion rate decreased with increase of interface strength between fiber and matrix. The mechanism was discussed with observation of fracture behavior of glass fiber.

Impingement Angle Dependence of Erosion Rate of Polyimide in Atomic Oxygen Exposures

2002 ◽  
Vol 39 (1) ◽  
pp. 155-156 ◽  
Author(s):  
Kumiko Yokota ◽  
Masahito Tagawa ◽  
Nobuo Ohmae
Keyword(s):  
Erosion Rate ◽  
Atomic Oxygen ◽  
Impingement Angle ◽  
Angle Dependence

Quantitative Electron Probe Microanalysis of Nonconducting Specimens: Science or Art?

2004 ◽  
Vol 10 (6) ◽  
pp. 733-738 ◽  
Author(s):  
Guillaume F. Bastin ◽  
Hans J.M. Heijligers
Keyword(s):  
Electrical Conductivity ◽  
Electron Probe Microanalysis ◽  
Electron Probe ◽  
Light Element ◽  
X Ray ◽  
Surface Charging ◽  
Quantitative Electron Probe Microanalysis ◽  
Quantitative Analyses ◽  
Intensity Ratios ◽  
Effect Of Surface

The influence of a lack of sufficient electrical conductivity on the results of quantitative electron probe microanalysis has been investigated on a number of oxides. The effect of surface charging and the way it alters the emitted X-ray signals has been studied. It is shown that the presence of conducting coatings, such as carbon or copper, will affect the interelement X-ray intensity ratios, whatever the thickness of the coating may be. Although the effects for heavier elements may be acceptable, they cannot be ignored for a light element such as oxygen, where strong variations with coating thickness were observed. Quantitative analyses of oxygen, on uncoated well-conducting oxide specimens, using uncoated well-conducting hematite (Fe2O3) as a standard yielded excellent results in the range between 4 and 40 kV with the φ(ρz) software used. As soon as coated nonconducting specimens were examined, using the same hematite standard, coated under exactly the same conditions, widely scattering and noncoherent results were obtained. These discrepancies can only be attributed to a lack of conductivity.

STUDY ON THE ATOMIC OXYGEN EROSION RESISTANCE OF POLY-Γ-AMINOPROPYLSILOXANE/METHYLPHENYLSILICONEHYBRID FILMS

2010 ◽  
Vol 24 (15n16) ◽  
pp. 3071-3076 ◽  
Author(s):  
WEI ZHAO ◽  
HUICONG LIU ◽  
WEIPING LI ◽  
LIQUN ZHU
Keyword(s):  
Mass Loss ◽  
Erosion Rate ◽  
Atomic Oxygen ◽  
Erosion Resistance ◽  
Hybrid Films ◽  
Hydrolytic Condensation ◽  
Atomic Oxygen Erosion

To improve the atomic oxygen (AO) erosion resistance of the polyimide (PI) maretials, cage-shaped poly-γ-aminopropylsiloxane (NPOSS) was synthesized from γ-aminopropyltriethoxysilane through the control of hydrolytic condensation conditions. Poly-γ-aminopropylsiloxane/methylphenylsilicone (NPOSS/MPS) hybrid films were prepared on PI samples. The physics and chemistry properties of the hybrid films surface was analyzed after exposure to AO flux in a ground AO simulated facility. The results showed that: NPOSS gathered to the spherical shapes and uniformly distributed in films, SiO 2 layer formed on the films surface after explorer and prevented the further AO erosion, mass loss and erosion rate of samples was dramatically decreased, AO erosion resistance had been increased and it could be further enhanced with the increase of NPOSS content.

First-principles modeling of GaN(0001)/water interface: Effect of surface charging

2019 ◽  
Vol 150 (15) ◽  
pp. 154703 ◽  
Author(s):  
Masahiro Sato ◽  
Yuki Imazeki ◽  
Katsushi Fujii ◽  
Yoshiaki Nakano ◽  
Masakazu Sugiyama
Keyword(s):  
First Principles ◽  
Interface Effect ◽  
Water Interface ◽  
Surface Charging ◽  
Effect Of Surface

Nucleation and initial growth of Pd2Si crystals on Si(111)

1993 ◽  
Vol 51 ◽  
pp. 844-845
Author(s):  
Xianghong Tong ◽  
Oliver Pohland ◽  
J. Murray Gibson
Keyword(s):  
High Vacuum ◽  
Dark Field ◽  
Ultra High Vacuum ◽  
Initial Growth ◽  
Surface And Interface ◽  
Dark Field Imaging ◽  
Transmission Electron ◽  
Initial Stage ◽  
Effect Of Surface

The nucleation and initial stage of Pd2Si crystals on Si(111) surface is studied in situ using an Ultra-High Vacuum (UHV) Transmission Electron Microscope (TEM). A modified JEOL 200CX TEM is used for the study. The Si(111) sample is prepared by chemical thinning and is cleaned inside the UHV chamber with base pressure of 1x10−9 τ. A Pd film of 20 Å thick is deposited on to the Si(111) sample in situ using a built-in mini evaporator. This room temperature deposited Pd film is thermally annealed subsequently to form Pd2Si crystals. Surface sensitive dark field imaging is used for the study to reveal the effect of surface and interface steps.The initial growth of the Pd2Si has three stages: nucleation, growth of the nuclei and coalescence of the nuclei. Our experiments shows that the nucleation of the Pd2Si crystal occurs randomly and almost instantaneously on the terraces upon thermal annealing or electron irradiation.

Charging microscopy and cathodoluminescence imaging of semi-insulating gallium arsenide

1986 ◽  
Vol 44 ◽  
pp. 816-817
Author(s):  
T.C. Sheu ◽  
S. Myhajlenko ◽  
D. Davito ◽  
J.L. Edwards ◽  
R. Roedel ◽  
...  
Keyword(s):  
Integrated Circuits ◽  
Secondary Electron ◽  
Crystal Defects ◽  
Device Performance ◽  
Gaas Wafer ◽  
Surface Charging ◽  
Gaas Substrates ◽  
Voltage Contrast ◽  
Cathodoluminescence Imaging ◽  
Scanning Electron

Liquid encapsulated Czochralski (LEC) semi-insulating (SI) GaAs has applications in integrated optics and integrated circuits. Yield and device performance is dependent on the homogeniety of the wafers. Therefore, it is important to characterise the uniformity of the GaAs substrates. In this respect, cathodoluminescence (CL) has been used to detect the presence of crystal defects and growth striations. However, when SI GaAs is examined in a scanning electron microscope (SEM), there will be a tendency for the surface to charge up. The surface charging affects the backscattered and secondary electron (SE) yield. Local variations in the surface charge will give rise to contrast (effectively voltage contrast) in the SE image. This may be associated with non-uniformities in the spatial distribution of resistivity. Wakefield et al have made use of “charging microscopy” to reveal resistivity variations across a SI GaAs wafer. In this work we report on CL imaging, the conditions used to obtain “charged” SE images and some aspects of the contrast behaviour.

EFFECT OF SURFACE CONDITIONS ON COERCIVITIES FOR Nd-Fe-B MAGNETS

1988 ◽  
Vol 49 (C8) ◽  
pp. C8-641-C8-642
Author(s):  
Y. Otani ◽  
H. Miyajima ◽  
S. Chikazumi ◽  
S. Hirosawa ◽  
M. Sagawa
Keyword(s):  
Surface Conditions ◽  
Effect Of Surface
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