Surface Analysis of UO2 Leached in Mineral Water Studied by X-Ray Photoelectron Spectroscopy

1988 ◽  
Vol 127 ◽  
Author(s):  
M. P. Lahalle ◽  
J. C. Krupa ◽  
R. Guillaumont ◽  
M. Genet ◽  
G. C. Allen ◽  
...  
Keyword(s):  
Surface Layer ◽  
Uranium Dioxide ◽  
Photoelectron Spectroscopy ◽  
Uranium Oxide ◽  
Mineral Water ◽  
Depth Profiling ◽  
X Rays ◽  
Xps Analysis ◽  
X Ray ◽  
Layer Analysis

ABSTRACTX-rays photoelectron spectroscopy (XPS) analysis has been carried out on uranium dioxide single crystals placed in both deionised or mineral water at 60 °C and 90 °C for a few months. The surface layer on the sample immersed in mineral water at 90 °C was sufficiently thick to mask the presence of uranium in the recorded XPS spectrum. Depth profiling experiments showed that the deposit was ∼ 100 nm in thickness and revealed the formation of a mixed magnesium-uranium oxide region between the bulk UO2 and the outer magnesium- rich layer. Analysis of the aqueous medium following immersion of the UO2 samples showed that the concentration of uranium released to the mineral water was 10 to 100 times lower than that in deionised water.

Near-Surface-Layer Analysis by Critical Takeoff-Angle X-Ray Fluorescence Detection

1992 ◽  
Vol 36 ◽  
pp. 257-262
Author(s):  
Shinjiro Hayakawa ◽  
Satoshi Sasaki ◽  
Yohichi Gohshi
Keyword(s):  
Thin Films ◽  
Surface Layer ◽  
Fluorescence Detection ◽  
Depth Profiling ◽  
Near Surface ◽  
X Ray ◽  
Angle Dependence ◽  
Layer Analysis ◽  
Takeoff Angle

AbstractNear-surface-layer analysis by x-ray fluorescence critical takeoff-angle detection was examined theoretically and experimentally. The takeoff-angle dependence of Cr K-L x-ray fluorescence from Cr thin films was measured with practical analyzed depth varying from several thousand to less than one hundred angstroms. Comparison of Cr K-L and K-M takeoff-angle dependence shows the analyzed depth depends on the observed x-ray energy even with identical takeoff angles. The potential of nondestructive depth profiling is also discussed.

Angle-Resolved X-Ray Depth Profiling: Interpretation of Angleresolved Profiles Using a Monte Carlo Approach

1999 ◽  
Vol 5 (S2) ◽  
pp. 582-583
Author(s):  
D.K. Wilkinson ◽  
M. Prutton ◽  
D.A. Loveday
Keyword(s):  
Monte Carlo ◽  
Electron Scattering ◽  
Photoelectron Spectroscopy ◽  
Depth Profiling ◽  
Incident Beam ◽  
Angle Of Incidence ◽  
X Rays ◽  
X Ray ◽  
Interaction Volume ◽  
Depth Profiles

A technique has been developed for the interpretation of composition depth profiles from angleresolved x-ray data using a Monte Carlo electron scattering simulation. Conventional methods for the interpretation of angle-resolved depth profiles used in the fields of x-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) assume that the outgoing signal is exponentially attenuated along its path. This assumption if not valid for angle-resolved x-ray techniques, as the x-ray signal is dependent on both the paths of the incident electrons and the path of the emitted x-rays. In this case, while the latter can be treated using an exponential attenuation, the path of the incident beam is more complex and corresponds to the well known “pear-shaped” interaction volume. In order to reliably interpret angle-resolved depth profiles in which the angle of the incident beam is varied, it is necessary to be able to obtain the distribution of x-ray emission within the sample for any angle of incidence.

Investigation of the Internal Chemical Composition of Chitosan-Based LbL Films by Depth-Profiling X-ray Photoelectron Spectroscopy (XPS) Analysis

Langmuir ◽  
2018 ◽  
Vol 34 (4) ◽  
pp. 1429-1440 ◽  
Author(s):  
Thiago B. Taketa ◽  
Danilo M. dos Santos ◽  
Anderson Fiamingo ◽  
Juliana M. Vaz ◽  
Marisa M. Beppu ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Photoelectron Spectroscopy ◽  
Depth Profiling ◽  
Xps Analysis ◽  
X Ray ◽  
Lbl Films

scholarly journals Mixed H2O/H2 Plasma-Induced Redox Reactions of Thin Uranium Oxide Films under UHV Conditions

2021 ◽  
Author(s):  
Ghada El Jamal ◽  
Thomas Gouder ◽  
Rachel Eloirdi ◽  
Evgenia Tereshina-Chitrova ◽  
Lukáš Horák ◽  
...  
Keyword(s):  
Thin Films ◽  
Photoelectron Spectroscopy ◽  
Redox Reactions ◽  
Uranium Oxide ◽  
Oxide Films ◽  
X Ray ◽  
Gas Plasma

X-Ray Photoelectron Spectroscopy (XPS) has been used to study the effect of mixed H2O/H2 gas plasma on the surface of UO2, U2O5 and UO3 thin films at 400 °C. The...

scholarly journals Chemical Abundances of Early Type Stars

1998 ◽  
Vol 188 ◽  
pp. 224-225
Author(s):  
S. Tanaka ◽  
S. Kitamoto ◽  
T. Suzuki ◽  
K. Torii ◽  
M.F. Corcoran ◽  
...  
Keyword(s):  
Surface Layer ◽  
Stellar Wind ◽  
Nuclear Reactions ◽  
X Rays ◽  
Early Type ◽  
Chemical Abundances ◽  
X Ray ◽  
Low Metallicity ◽  
Early Type Stars

X-rays from early-type stars are emitted by the corona or the stellar wind. The materials in the surface layer of early-type stars are not contaminated by nuclear reactions in the stellar inside. Therefore, abundance study of the early-type stars provides us an information of the abundances of the original gas. However, the X-ray observations indicate low-metallicity, which is about 0.3 times of cosmic abundances. This fact raises the problem on the cosmic abundances.

Formation of GaN Self-Organized Nanotips by Nanomasking Effect

2001 ◽  
Vol 707 ◽  
Author(s):  
Harumasa Yoshida ◽  
Tatsuhiro Urushido ◽  
Hideto Miyake ◽  
Kazumasa Hiramtsu
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Aspect Ratio ◽  
Formation Mechanism ◽  
High Aspect Ratio ◽  
Photoelectron Spectroscopy ◽  
Nanometer Scale ◽  
Xps Analysis ◽  
X Ray ◽  
Self Organized

ABSTRACTWe have successfully fabricated self-organized GaN nanotips by reactive ion etching using chlorine plasma, and have revealed the formation mechanism. Nanotips with a high density and a high aspect ratio have been formed after the etching. We deduce from X-ray photoelectron spectroscopy (XPS) analysis that the nanotip formation is attributed to nanometer-scale masks of SiO2 on GaN. The structures calculated by Monte Carlo simulation of our formation mechanism are very similar to the experimental nanotip structures.

Comparative Study of Time-Dependent PAES and XPS on a Ni/Pd Surface

2017 ◽  
Vol 373 ◽  
pp. 313-316 ◽  
Author(s):  
Samantha Zimnik ◽  
Christian Piochacz ◽  
Sebastian Vohburger ◽  
Christoph Hugenschmidt
Keyword(s):  
Photoelectron Spectroscopy ◽  
Electron Spectroscopy ◽  
Auger Electron ◽  
Structural Changes ◽  
Time Dependent ◽  
Xps Analysis ◽  
Time Constants ◽  
X Ray ◽  
Residual Gas ◽  
Rule Out

We report on time-dependent Positron annihilation induced Auger Electron Spectroscopy (PAES) study on 0.5 monolayers (ML) Ni on polycrystalline Pd accompanied by complementary X-ray induced Photoelectron Spectroscopy (XPS). The normalized PAES spectra showed a significant decrease in the Ni intensity and an increase in the Pd intensity as a function of time. To rule out varying influence on the elements e.g. from surface contaminates due to the residual gas, a time-dependent XPS analysis was performed on pure Ni and Pd as well as to analyze the main contaminants C and O. The O fraction was found to be constant within the measurement time and the time constants for C significantly differ from those of Ni and Pd in the PAES data. Consequently, it was concluded that the PAES data show a superposition of C contamination and structural changes at the surface of Ni/Pd.

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