scholarly journals Comments on the XPS Analysis of Carbon Materials

2021 ◽  
Vol 7 (3) ◽  
pp. 51
Author(s):  
David J. Morgan
Keyword(s):  
Surface Chemistry ◽  
Photoelectron Spectroscopy ◽  
Spectroscopic Data ◽  
Carbon Materials ◽  
Core Level ◽  
Spectral Envelope ◽  
Xps Analysis ◽  
X Ray ◽  
Logical Approach ◽  
Carbon Core

The surface chemistry of carbon materials is predominantly explored using x-ray photoelectron spectroscopy (XPS). However, many published papers have critical failures in the published analysis, stemming from an ill-informed approach to analyzing the spectroscopic data. Herein, a discussion on lineshapes and changes in the spectral envelope of predominantly graphitic materials are explored, together with the use of the D-parameter, to ascertain graphitic content, using this information to highlight a simple and logical approach to strengthen confidence in the functionalization derived from the carbon core-level spectra.

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.

Xps Analysis of the Sapphire Surface as a Function of High Temperature Vacuum Annealing

1989 ◽  
Vol 159 ◽  
Author(s):  
E.D. Richmond
Keyword(s):  
High Temperature ◽  
Binding Energy ◽  
Photoelectron Spectroscopy ◽  
Vacuum Annealing ◽  
Xps Analysis ◽  
Chemical Changes ◽  
Cleaning Procedure ◽  
Sapphire Surface ◽  
X Ray ◽  
First Time

ABSTRACTFor the first time the (1102) surface of sapphire has been investigated by X-ray photoelectron spectroscopy to ascertain chemical changes resulting from annealing in vacuum at 1300° C and 1450° C. As received substrates had a substantial surface C contaminant. For substrates that were chemically cleaned before inserting them into the MBE system no trace of carbon is detected. A residual flourine contaminant results from the cleaning procedure and is desorbed by the vacuum annealing. Spectra of annealed substrates are compared to the unannealed chemically cleaned substrates. The annealed substrates exhibit 0.4 to 0.5 eV shift to higher binding energy of the Al peak and a 0.3 eV shift to higher binding energy of the O peak. In addition, a 2% depletion of oxygen from the surface occurs.

scholarly journals On the prediction of core level binding energies in molecules, surfaces and solids

2018 ◽  
Vol 20 (13) ◽  
pp. 8403-8410 ◽  
Author(s):  
Francesc Viñes ◽  
Carmen Sousa ◽  
Francesc Illas
Keyword(s):  
Photoelectron Spectroscopy ◽  
State Of The Art ◽  
Binding Energies ◽  
Core Level ◽  
Chemical Environment ◽  
X Ray ◽  
Unique Information

Core level binding energies, measured by X-ray photoelectron spectroscopy providing unique information regarding the chemical environment of atoms in a system, can be estimated by a diversity of state-of-the-art accurate methods here detailed.

scholarly journals Synthesis of 1-(2-Hydroxyphenyl) Dec-2-en-1-One Oxime and Its Flotation and Adsorption Behavior for Malachite

2020 ◽  
Vol 8 ◽  
Author(s):  
Liqing Li ◽  
Lin Yang ◽  
Fangxu Li
Keyword(s):  
Photoelectron Spectroscopy ◽  
Adsorption Behavior ◽  
Xps Analysis ◽  
X Ray ◽  
Benzohydroxamic Acid ◽  
Wide Ph Range ◽  
Flotation Performance ◽  
Ph Range

A novel collector of 1-(2-hydroxyphenyl) dec-2-en-1-one oxime (HPDO) was synthesized from 2-hydroxy acetophenone and octanal, and its flotation and adsorption behavior for malachite were studied by flotation tests and x-ray photoelectron spectroscopy (XPS) analysis. The flotation results of a single mineral show HPDO is a special collector for malachite. Compared with benzohydroxamic acid (BHA), isobutyl xanthate (SIBX), and dodecylamine (DA), HPDO exhibits excellent flotation performance for malachite and satisfied selectivity against quartz and calcite over a wide pH range. The HPDO with a concentration of 200 mg/L can float 94% malachite at pH 8, while only recovering 7.8% quartz and 28% calcite. XPS data give clear evidence for the formation of a Cu-oxime complex on malachite surfaces after HPDO adsorption.

scholarly journals Effect of Nitric Acid Modification on Characteristics and Adsorption Properties of Lignite

Processes ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 167 ◽  
Author(s):  
Bo Huang ◽  
Guowei Liu ◽  
Penghui Wang ◽  
Xiang Zhao ◽  
Hongxiang Xu
Keyword(s):  
Nitric Acid ◽  
Surface Chemistry ◽  
Pore Structure ◽  
Surface Properties ◽  
Photoelectron Spectroscopy ◽  
Metal Ion ◽  
Adsorption Properties ◽  
Acid Modification ◽  
X Ray ◽  
Adsorption Performance

The objective of this research was to explore the changes of the pore structure and surface properties of nitric-modified lignite and base the adsorption performance on physical and chemical adsorbent characteristics. To systematically evaluate pore structure and surface chemistry effects, several lignite samples were treated with different concentrations of nitric acid in order to get different pore structure and surface chemistry adsorbent levels. A common heavy metal ion contaminant in water, Pb2+, served as an adsorbate probe to demonstrate the change of modified lignite adsorption properties. The pore structure and surface properties of lignite samples before and after modification were characterized by static nitrogen adsorption, X-ray diffraction, Scanning electron microscope, Fourier transform infrared spectroscopy, zeta potential, and X-ray photoelectron spectroscopy. The experimental results showed that nitric acid modification can increase the ability of lignite to adsorb Pb2+. The adsorption amount of Pb2+ increased from 14.45 mg·g−1 to 30.68 mg·g−1. Nitric acid reacted with inorganic mineral impurities such as iron dolomite in lignite and organic components in coal, which caused an increase in pore size and a decrease in specific surface areas. A hydrophilic adsorbent surface more effectively removed Pb2+ from aqueous solution. Nitric acid treatment increased the content of polar oxygen-containing functional groups such as hydroxyl, carbonyl, and carboxyl groups on the surface of lignite. Treatment introduced nitro groups, which enhanced the negative electrical properties, the polarity of the lignite surface, and its metal ion adsorption performance, a result that can be explained by enhanced water adsorption on hydrophilic surfaces.

Surface Analysis, Microstructural Characterization and Local Corrosion Processes in Decarburized SAE 9254 Spring Steel

CORROSION ◽  
10.5006/3234 ◽  
2019 ◽  
Vol 75 (12) ◽  
pp. 1474-1486
Author(s):  
Jéssica Cristina Costa de Castro Santana ◽  
Rejane Maria Pereira da Silva ◽  
Renato Altobelli Antunes ◽  
Sydney Ferreira Santos
Keyword(s):  
Surface Chemistry ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Microstructural Characterization ◽  
Spring Steel ◽  
Laser Scanning Microscopy ◽  
Local Corrosion ◽  
Confocal Laser ◽  
X Ray ◽  
Decarburized Layer

The aim of the present work was to study the surface chemistry, microstructure, and local corrosion processes at the decarburized layer of the SAE 9254 automotive spring steel. The samples were austenitized at 850°C and 900°C, and oil quenched. The microstructure was investigated using confocal laser scanning microscopy and scanning electron microscopy. The surface chemistry was analyzed by x-ray photoelectron spectroscopy. Electrochemical impedance spectroscopy and potentiodynamic polarization were used to assess the global corrosion behavior of the decarburized samples. Scanning electrochemical microscopy was used to evaluate the influence of decarburization on the local corrosion activity. Microstructural characterization and x-ray photoelectron spectroscopy analysis indicate a dependence of the local electrochemical processes with the steel microconstituents and Si oxides in the decarburized layer.

scholarly journals Effect of electron correlation in the decomposition of core level binding energy shifts into initial and final state contributions

2019 ◽  
Vol 21 (18) ◽  
pp. 9399-9406 ◽  
Author(s):  
Marc Figueras ◽  
Carmen Sousa ◽  
Francesc Illas
Keyword(s):  
Binding Energy ◽  
Electron Correlation ◽  
Photoelectron Spectroscopy ◽  
Core Level ◽  
Final State ◽  
X Ray ◽  
Core Level Binding Energy

The influence of electron correlation into the decomposition of core level binding energy shifts, measured by X-ray photoelectron spectroscopy (XPS), into initial and final effects is analysed for a series of molecules where these effects are noticeable.

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