X-ray photoelectron spectroscopic characterization of Silica Springs allophane

Clay Minerals ◽  
1997 ◽  
Vol 32 (4) ◽  
pp. 565-572 ◽  
Author(s):  
C. W. Childs ◽  
K. Inoue ◽  
H. Seyama ◽  
M. Soma ◽  
B. K. G. Theng ◽  
...  
Keyword(s):  
New Zealand ◽  
Photoelectron Spectroscopy ◽  
Spectroscopic Characterization ◽  
Binding Energies ◽  
Surface Enrichment ◽  
Auger Electrons ◽  
X Ray ◽  
C And N ◽  
Bulk Structure

AbstractA range of allophane samples (atomic AI/Si bulk ratios 1.1-1.9) from Silica Springs, New Zealand, has been characterized by X-ray photoelectron spectroscopy (XPS). Binding energies of Si 2s, Si 2p, Al 2p, O 1s, C 1s, and N 1s electrons, together with the kinetic energies of Al KL23L23 Auger electrons, at or near the surface of allophane aggregates, have been derived. The values for Al, Si and O electrons are similar to those for kaolinite but also to those for some framework silicates (feldspars) having 4-coordinate Al. Values for N electrons suggest that N occurs in organic structures. Comparison of XPS and bulk Al/Si ratios shows an enrichment of Al at or near the surface of allophane aggregates. The same is true for C and N. Extraction with citrate-dithionite-bicarbonate (CDB) reagent leaves the surfaces depleted in Al. The CDB extracts have higher Al/Si ratios than the bulk allophanes. Similarly, CDB treatment reduces the degree of surface enrichment of C and N. Small increases in the binding energies of Si electrons following CDB treatment suggest partial dissolution of the bulk structure though a concomitant removal of a separate phase or species cannot be ruled out. The results may be accounted for in terms of the structure previously suggested for the primary spherules of Silica Springs allophane (Childs et al., 1990) though the composition of the spherules at or near the surface of the allophane aggregates is different from those of the bulk.

Spectroscopic Characterization of Wilkinson's Catalyst Using X-ray Photoelectron Spectroscopy (ESCA)

1982 ◽  
Vol 36 (3) ◽  
pp. 290-296 ◽  
Author(s):  
Manuel Carvalho ◽  
Larry F. Wieserman ◽  
David M. Hercules
Keyword(s):  
Binding Energy ◽  
Photoelectron Spectroscopy ◽  
Analytical Techniques ◽  
Spectroscopic Characterization ◽  
Homogeneous Hydrogenation ◽  
X Ray ◽  
Wilkinson’S Catalyst ◽  
Ft Ir ◽  
Wilkinson's Catalyst

Wilkinson's catalyst, RhCl(PPh3)3 is a well known and widely used homogeneous hydrogenation catalyst. This catalyst was analyzed by ESCA which revealed that two rhodium species [Rh(I) and Rh(III)] were present, both for commercial preparations and for catalysts prepared in this laboratory. The ratio of Rh(I) to Rh(III) was 3:2 regardless of the source. A different method of synthesizing RhCl(PPh3)3 was used and produced a compound having only Rh(I) species. Additional analytical techniques such as elemental analysis, FT-IR, liquid chromatography, and 31P NMR were used to determine the origin of the higher binding energy peaks when Wilkinson's procedure was used to prepare RhCl(PPh3)3. Hydrogenation of cyclohexene was also performed to determine the effect of the higher binding energy species on catalytic activity.

X-ray photoelectron spectroscopy characterization of aerosol particles in Antarctica

2015 ◽  
Vol 27 (5) ◽  
pp. 493-499 ◽  
Author(s):  
Simona Rella ◽  
Cosimino Malitesta
Keyword(s):  
Photoelectron Spectroscopy ◽  
Surface Characterization ◽  
Chemical Elements ◽  
Aerosol Particles ◽  
Qualitative And Quantitative Analysis ◽  
Surface Enrichment ◽  
X Ray ◽  
Qualitative And Quantitative

AbstractQualitative and quantitative analysis of surface species on size-segregated atmospheric particulate collected in Antarctica during the 2010–11 summer was performed by X-ray photoelectron spectroscopy (XPS). This represents the first example of surface characterization of Antarctic aerosols. The size class with particle cut-off diameter of 3 μm was richest in terms of chemical elements. Peculiar findings of the application included detection of Ca (possibly surface-segregated) and surface enrichment of Mg. The determination of nitrate, ammonium and sulphate species on collection filters provides evidence for a possible advantage of XPS over more laborious techniques (e.g. ion chromatography). The presence of these species is in reasonable agreement with other recent reports from Antarctica.

Characterization of Oxidized Nickel (II) Dimethylglyoxime Using X-Ray Photoelectron Spectroscopy

1987 ◽  
Vol 41 (6) ◽  
pp. 994-1000 ◽  
Author(s):  
V. Y. Young ◽  
F. C. Chang ◽  
K. L. Cheng
Keyword(s):  
Oxidation State ◽  
Photoelectron Spectroscopy ◽  
Binding Energies ◽  
Core Level ◽  
Solution Phase ◽  
Intensity Data ◽  
X Ray ◽  
Complex Core

X-ray photoelectron spectroscopy has been used to determine the oxidation state of nickel in the oxidized nickel (II) dimethylglyoxime complex. Core level binding energies for the Ni(2p), N(1s), and O(1s) levels; the presence or absence of shake-up satellites on the Ni(2p) levels; and the analysis of intensity data are consistent only with an assignment of +3. Structures consistent with the data are proposed for both the solid-and the solution-phase complexes.

Surface Characterization of Clean Gd5Ge4(010)

2012 ◽  
Vol 1517 ◽  
Author(s):  
Chad D. Yuen ◽  
Gordon J. Miller ◽  
Patricia A. Thiel
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Photoelectron Spectroscopy ◽  
Surface Characterization ◽  
Surface Segregation ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
X Ray ◽  
Show Evidence ◽  
Bulk Structure

AbstractBased on X-ray photoelectron spectroscopy, Gd5Ge4(010) does not show evidence of surface segregation. Scanning tunneling microscopy reveals two types of terraces which alternate laterally on the surface. From the step heights, these two surface terminations are assigned as dense, Gd-pure layers in the bulk structure. There is evidence of reconstruction on one type of terrace.

Characterization of Fluorinated Polyimide Films

1992 ◽  
Vol 264 ◽  
Author(s):  
Pradnya V. Nagarkar ◽  
Jiong Ping Lu ◽  
David Volfson ◽  
Klavs F. Jensen ◽  
Stephen D. Senturia
Keyword(s):  
Photoelectron Spectroscopy ◽  
Polyimide Film ◽  
Binding Energies ◽  
Polyimide Films ◽  
Chemical Modifications ◽  
X Ray ◽  
Fluorinated Polyimide ◽  
Peak Assignment ◽  
Good Agreement

Abstract:X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) have been used to characterize the polyimide film based on 4,4′ hexafluoro-isopropylidene -bis pthalic anhydride (HFDA) and 4,4′ -bis (4-aminophenoxy) biphenyl (APBP). Films of varying thicknesses made from diluted precursors were studied by IR and XPS. An elemental analysis and a tentative peak assignment for C 1s in XPS is presented. The HFDA-APBP thick films are stoichiometric in composition and binding energies are in good agreement with data on hexafluorodianhydride-oxydianiline (HFDA-ODA). For thinner films, certain chemical modifications were observed at high cure temperatures.

In situ X-ray photoelectron and Auger electron spectroscopic characterization of reaction mechanisms during Li-ion cycling

2016 ◽  
Vol 52 (90) ◽  
pp. 13257-13260 ◽  
Author(s):  
Ching-Yen Tang ◽  
Richard T. Haasch ◽  
Shen J. Dillon
Keyword(s):  
Photoelectron Spectroscopy ◽  
Reaction Mechanisms ◽  
Electron Spectroscopy ◽  
Auger Electron ◽  
Spectroscopic Characterization ◽  
X Ray ◽  
Li Ion ◽  
Novel Design

We demonstrate a novel design for in situ X-ray photoelectron spectroscopy and in situ Auger electron spectroscopy, and we applied this technique to characterize the evolution of bonding and chemistry during cycling of nanoparticle electrodes.

Surface Characterization of Amalgams Using X-ray Photoelectron Spectroscopy

1987 ◽  
Vol 66 (9) ◽  
pp. 1470-1478 ◽  
Author(s):  
T. Hanawa ◽  
H. Takahashi ◽  
M. Ota ◽  
R.F. Pinizzotto ◽  
J.L. Ferracane ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Surface Characterization ◽  
Surface Film ◽  
Binding Energies ◽  
Minimal Amount ◽  
Surface Films ◽  
X Ray ◽  
Argon Ion ◽  
Electron Binding Energies

This study is the first to report on the use of x-ray photoelectron spectroscopy (XPS or ESCA) for studying the surface films (less than 10 nm thick) of aged amalgams. The concentrations and electron binding energies of the elements on the surfaces of four different amalgams aged for 20 min, one day, seven days, and 30 days were determined quantitatively. For comparison, the bulk compositions of the amalgams aged for seven days were also determined after removal of approximately 5 nm of material from the surface by argon-ion-sputtering. The XPS data revealed that the surface films of aged zinc-containing amalgams were not a simple oxide but were primarily composed of a (hydrated) tin and zinc oxy-hydroxide, whereas, in the zinc-free amalgams, the surface films were primarily a tin oxide. The concentration of mercury in this thin surface film after aging was depleted. This suggests that tin and/or zinc preferentially diffused to the surface and combined with oxygen, forming a surface film and diluting the mercury concentration in the surface. Another probable explanation for the depleted mercury is that a minimal amount of mercury in the surface film evaporated during the aging.

scholarly journals Structural and Electronic Characterization of CuxBi2Se3

2017 ◽  
Vol 60 (3) ◽  
Author(s):  
Paola Arévalo López ◽  
Francisco Morales Leal ◽  
Roberto Escudero Derat
Keyword(s):  
Topological Insulator ◽  
Structural Characterization ◽  
Photoelectron Spectroscopy ◽  
Binding Energies ◽  
X Ray Diffraction ◽  
X Ray ◽  
Chemical Studies

Topological insulator Bi2Se3 becomes superconductor when it is intercalated with copper. In this work, we present our studies related to the electronic and structural characterization of CuxBi2Se3 with Cu variation from x = 0.11 to 0.20. We show structural and chemical studies performed via X-ray diffraction and photoelectron spectroscopy. Cu insertion modifies the Bi and Se binding energies and induces superconductivity in the compound.

scholarly journals X-ray Photoelectron Spectroscopic Characterization of Au Collected with Atom Trapping on Silica for Atomic Absorption Spectrometry

1997 ◽  
Vol 51 (10) ◽  
pp. 1537-1539 ◽  
Author(s):  
Ş. Süzer ◽  
N. Ertaş ◽  
S. Kumser ◽  
O. Y. Ataman
Keyword(s):  
Binding Energy ◽  
Atomic Absorption ◽  
Absorption Spectrometry ◽  
Platinum Metal ◽  
Spectroscopic Characterization ◽  
Binding Energies ◽  
Atom Trapping ◽  
X Ray ◽  
Two Peaks

The nature of analyte species collected on a cooled silica tube for atom-trapping atomic absorption spectrometric determination was investigated with the use of X-ray photoelctron spectroscopy (XPS). An XPS spectrum of gold deposited on atom-trapping silica tubes reveals a Au 4f7/2 peak with a binding energy of 84.8 (±0.2) eV, which falls in the middle of the binding energies corresponding to zerovalent Au(0) at 84.0 eV and that of monovalent Au(I) at 85.2 eV. The corresponding energy for Au vapor deposited on silica is also 84.8 eV. Deposition of AuCl4- solution on silica results in two different Au 4f7/2 peaks with binding energies of 84.8 and 87.3 eV corresponding, respectively, to Au(0) and Au(III). Deposition of the same AuCl4- solution on platinum metal again gives two peaks, this time at 84.4 and 87.0 eV energies corresponding again to Au(0) and Au(III). Combining all these data, we conclude that gold is trapped on atom-trapping silica surface as zerovalent Au(0) with a 0.8-eV matrix shift with respect to the metal surface. A similar 0.6-eV shift is also observed between the binding energy of 4f7/2Hg22+ measured in Hg2(NO3)2·2H2O powder and that deposited on silica.

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