New interpretation and approach to curve fitting synchrotron X-ray photoelectron spectra of (Fe,Ni)9S8 fracture surfaces

2020 ◽  
Vol 504 ◽  
pp. 144458 ◽  
Author(s):  
Zoe E. Pettifer ◽  
Jamie S. Quinton ◽  
William M. Skinner ◽  
Sarah L. Harmer
Keyword(s):  
Curve Fitting ◽  
Photoelectron Spectra ◽  
X Ray ◽  
Fracture Surfaces ◽  
New Interpretation

scholarly journals Curve fitting complex X-ray photoelectron spectra of graphite-supported copper nanoparticles using informed line shapes

2020 ◽  
Vol 505 ◽  
pp. 143841 ◽  
Author(s):  
Vincent Fernandez ◽  
Daniyal Kiani ◽  
Neal Fairley ◽  
François-Xavier Felpin ◽  
Jonas Baltrusaitis
Keyword(s):  
Copper Nanoparticles ◽  
Curve Fitting ◽  
Photoelectron Spectra ◽  
X Ray ◽  
Line Shapes

Exploiting XPS for the identification of sulfides and polysulfides

RSC Advances ◽  
2015 ◽  
Vol 5 (93) ◽  
pp. 75953-75963 ◽  
Author(s):  
Marzia Fantauzzi ◽  
Bernhard Elsener ◽  
Davide Atzei ◽  
Americo Rigoldi ◽  
Antonella Rossi
Keyword(s):  
Curve Fitting ◽  
Photoelectron Spectra ◽  
X Ray ◽  
Auger Spectra ◽  
First Time

The identification of surface sulfide and polysulfide species based on the curve fitting of S2p photoelectron spectra and, for the first time, of X-ray excited S KLL Auger spectra has been performed.

Analysis of X-ray Photoelectron Spectra through Their Even Derivatives

1979 ◽  
Vol 33 (5) ◽  
pp. 502-509 ◽  
Author(s):  
Attila E. Pavlath ◽  
Merle M. Millard
Keyword(s):  
Curve Fitting ◽  
Photoelectron Spectroscopy ◽  
Least Square ◽  
Photoelectron Spectra ◽  
Original Position ◽  
Noise Background ◽  
X Ray ◽  
Fitting Procedures ◽  
Higher Derivatives ◽  
Derivatives Of

The analysis of organic and inorganic surfaces can be carried out very effectively with the aid of x-ray photoelectron spectroscopy. In many cases, however, the presently available methods and techniques for data treatment resolutions are not suitable for the qualitative and quantitative identification of the various forms of a given atom on the same surface. The number of components and a good approximation of their original position in the composite curve must be known to use the available curve fitting procedures, otherwise the evaluation can be unreliable. It is suggested that the second and higher even derivatives of the composite could provide these data. The possibility of applying even derivatives of composite curves in combination with a nonlinear least square curve fitting program was investigated. It was found that depending on the noise background of the spectra, the resolution could be improved through this method. The resolution is dependent on the half-width of the component curves, their separation, and ratio. Both Gaussian and Lorentzian curves can be resolved, but the resolution of the latter is easier. The resolution is increasing with higher derivatives; however, increased smoothing must be applied at each step to neutralize the influence of the noise background.

scholarly journals Least squares curve fitting in Mo3d X-ray photoelectron spectra for determination of oxidation states of supported molybdenum catalysts.

1989 ◽  
Vol 38 (2) ◽  
pp. 65-71
Author(s):  
Natsuo FUKUMOTO ◽  
Isao KOJIMA ◽  
Masayasu KURAHASHI ◽  
Hiromichi SHIMADA ◽  
Akio NISHIJIMA
Keyword(s):  
Least Squares ◽  
Curve Fitting ◽  
Photoelectron Spectra ◽  
Oxidation States ◽  
X Ray ◽  
Molybdenum Catalysts ◽  
Least Squares Curve Fitting ◽  
Fitting In

Valence and Core Electron Spectra of Mg in MgO in Evoporated Thin Films

1975 ◽  
Vol 30 (11) ◽  
pp. 1485-1490 ◽  
Author(s):  
N. C. Haider ◽  
J. Alonso ◽  
W. E. Swartz
Keyword(s):  
Thin Films ◽  
Valence Band ◽  
Binding Energies ◽  
Photoelectron Spectra ◽  
High Quality ◽  
Core Electron ◽  
X Ray ◽  
Electron Spectra ◽  
Contamination Effect ◽  
New Interpretation

X-ray photoelectron spectra (XPS) are obtained for Mg in MgO using high quality (purity 99.999%) Mg films prepared and oxidized under pressures of 10-6 ~ 10-8 torr and measured on an ESCA-36 spectrometer at a pressure of 10-8 torr. AlKα line source was used for excitation, and the minimum of Au valence band at 5.0 eV was chosen for calibration.With increased oxidation the valence band shifts about 1.0 eV towards the Fermi level, but with extreme contamination it disappears completely. Accurate measurements of binding energies have been made of Mg in pure Mg, and Mg in MgO. The average shift resulting from oxidation is 1.1 eV for Mg(2s) and 1.5 eV for Mg(2p) core levels. It is also observed that the contamination effect due to oxygen decreases with increasing film thickness. The present results are compared with the previous results, and a new interpretation is offered by postulating the formation of two kinds of oxides, stoichiometric and chemisorbed layers in Mg on oxidation

X-ray photoelectron spectra of C6F5X compounds (X = CH3, CF3, CN, CHO, OH, OCH3, NH2, NO2)

1978 ◽  
Vol 56 (4) ◽  
pp. 538-542 ◽  
Author(s):  
Barry C. Trudell ◽  
S. James W. Price
Keyword(s):  
Gas Phase ◽  
Curve Fitting ◽  
Binding Energies ◽  
Photoelectron Spectra ◽  
Atomic Charges ◽  
X Ray ◽  
Wide Range ◽  
Charge Calculations

The gas phase photoelectron spectra, XPS, were observed for the series C6F5X (X = CH3, CF3, OCH3, OH, CHO, NO2, NH2, CN). Binding energies were determined from the spectra by using computer curve fitting. Charge calculations were carried out using CNDO/2 and ACHARGE techniques. The CNDO/2 analysis led to the following correlation for the C 1s binding energies and the atomic charges, qi[Formula: see text]Correlations were also obtained for O 1s and N 1s:[Formula: see text]These equations are based on only four and three points respectively. However, the N 1s values cover a wide range (Ei, 402 to 419 eV; qi, −0.2 to 0.5) and show a better correlation than those for oxygen.

scholarly journals Modification of Wood with Monoethanolamino-borate by The Data of X-Ray Photoelectron Spectroscopy

2018 ◽  
Vol 196 ◽  
pp. 04005
Author(s):  
Irina Stepina ◽  
Irina Kotlyarova
Keyword(s):  
Particle Size ◽  
Photoelectron Spectroscopy ◽  
Model Compound ◽  
Hydrolytic Stability ◽  
Photoelectron Spectra ◽  
Wood Cellulose ◽  
Rapid Loss ◽  
X Ray ◽  
Wood Protection ◽  
Cellulose Materials

The difficulty of wood protection from biocorrosion and fire is due to the fact that modifiers in use are washed out from the surface of the substrate under the influence of environmental factors. This results in a rapid loss of the protective effect and other practically important wood characteristics caused by the modification. To solve this problem is the aim of our work. Here, monoethanolaminoborate is used as a modifier, where electron-donating nitrogen atom provides a coordination number equal to four to a boron atom, which determines the hydrolytic stability of the compounds formed. Alpha-cellulose ground mechanically to a particle size of 1 mm at most was used as a model compound for the modification. X-ray photoelectron spectra were recorded on the XSAM-800 spectrometer (Kratos, UK). Prolonged extraction of the modified samples preceded the registration of the photoelectron spectra to exclude the fixation of the modifier molecules unreacted with cellulose. As a result of the experiment, boron and nitrogen atoms were found in the modified substrate, which indicated the hydrolytic stability of the bonds formed between the modifier molecules and the substrate. Therefore monoethanolaminoborate can be considered as a non-extractable modifier for wood-cellulose materials.

scholarly journals Impact of high temperatures on aluminoceladonite studied by Mössbauer, Raman, X-ray diffraction and X-ray photoelectron spectroscopy

2021 ◽  
Author(s):  
Mariola Kądziołka-Gaweł ◽  
Maria Czaja ◽  
Mateusz Dulski ◽  
Tomasz Krzykawski ◽  
Magdalena Szubka
Keyword(s):  
Photoelectron Spectroscopy ◽  
Integral Intensity ◽  
Photoelectron Spectra ◽  
X Ray Diffraction ◽  
Structural Reorganization ◽  
Oh Groups ◽  
X Ray ◽  
Al Content ◽  
Integral Intensity Ratio ◽  
Higher Temperature

AbstractMössbauer, Raman, X-ray diffraction and X-ray photoelectron spectroscopies were used to examine the effects of temperature on the structure of two aluminoceladonite samples. The process of oxidation of Fe2+ to Fe3+ ions started at about 350 °C for the sample richer in Al and at 300 °C for the sample somewhat lower Al-content. Mössbauer results show that this process may be associated with dehydroxylation or even initiate it. The first stage of dehydroxylation takes place at a temperature > 350 °C when the adjacent OH groups are replaced with a single residual oxygen atom. Up to ~500 °C, Fe ions do not migrate from cis-octahedra to trans-octahedra sites, but the coordination number of polyhedra changes from six to five. This temperature can be treated as the second stage of dehydroxylation. The temperature dependence on the integral intensity ratio between bands centered at ~590 and 705 cm−1 (I590/I705) clearly reflects the temperature at which six-coordinated polyhedra are transformed into five-coordinated polyhedra. X-ray photoelectron spectra obtained in the region of the Si2p, Al2p, Fe2p, K2p and O1s core levels, highlighted a route to identify the position of Si, Al, K and Fe cations in a structure of layered silicates with temperature. All the measurements show that the sample with a higher aluminum content and a lower iron content in octahedral sites starts to undergo a structural reorganization at a relatively higher temperature than the less aluminum-rich sample does. This suggests that iron may perform an important role in the initiation of the dehydroxylation of aluminoceladonites.

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