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

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.

2010 ◽  
Vol 657 ◽  
pp. 35-45 ◽  
Author(s):  
Asif A. Qaiser ◽  
Margaret M. Hyland

X-ray photoelectron spectroscopy (XPS) is a promising technique employed for the study of conducting polymers and their composites. XPS was used to study the surface chemistry of polyaniline-mixed cellulose ester (PANI-ME) composite membranes prepared by various chemical oxidative polymerization techniques such as insitu solution, vapour phase polymerizations and aniline polymerization using a two-compartment permeation cell. Hydrolytic degradation of surface deposited PANI and scission of cellulosic chains due to x-ray irradiation inside the XPS chamber influenced the quantification of polyaniline deposition levels as well as oxidation and doping states in PANI-ME membranes. N1s core level spectra allowed characterization of the PANI deposition level, its oxidation state and x-ray induced cellulosic ring cleavage. C1s and O1s core level spectra revealed PANI hydrolysis at the membrane surface. These degradation phenomena influence the performance of PANI composite membranes used specifically in electrodiffusion applications. It was shown that successful quantification of PANI deposition levels and its oxidation state on microporous mixed cellulose ester membranes using XPS could be realized by incorporating the degradation effects in the characterization results.


2018 ◽  
Vol 20 (13) ◽  
pp. 8403-8410 ◽  
Author(s):  
Francesc Viñes ◽  
Carmen Sousa ◽  
Francesc Illas

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.


Clay Minerals ◽  
1982 ◽  
Vol 17 (4) ◽  
pp. 477-481 ◽  
Author(s):  
S. Evans ◽  
E. Raftery

It is usually assumed that the oxidation state of the small proportion of Mn sometimes present in micas is +2, although there is evidence from electronic spectroscopy (Burns, 1970) for at least the occasional occurrence of Mn(III) in manganophyllite. We describe here X-ray photoelectron spectroscopic (XPS) measurements on the Mn in a Norwegian lepidolite which was the subject of a concurrent structural study by X-ray photoelectron diffraction (Evans & Raftery, 1982). To establish the Mn oxidation state we have compared the Mn2p core-electron binding energies (BE), the Mn2P3/2-O ls BE differences, and the Mn2p XPS peak profiles from the four common oxides of manganese (MnO, Mn3O4, Mn2O3 and MnO2) with those from the lepidolite. A re-examination of these oxides was undertaken because the agreement between reports in the literature was unsatisfactory, and uncertainty existed concerning the integrity of some of the surfaces previously examined.


1993 ◽  
Vol 333 ◽  
Author(s):  
S. Sunder ◽  
N.H. Miller ◽  
A.M. Duclos

ABSTRACTMineral samples from the natural fission reactors 10 and 13 in the Oklo uranium deposits were studied using X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) to gain information about the long-term behaviour of UO2 fuel in a geological disposal vault. Two samples from reactor zone 10 (samples # D81N-190292 and D73-88) and one sample from reactor zone 13 (sample # SD37-S2/CD) were analysed. Low-resolution XPS spectra were recorded to determine the major elements present in the ore. High-resolution spectra were recorded to gain information about the chemical state of the elements present in the mineral samples. The samples show low values for the U6+/U4+ ratio. The oxidation state of uranium in these samples is even lower than that in U409. The binding energies of the Pb 4f bands indicate most of the Pb is in the +2 oxidation state in these samples. The C Is band indicates the presence of organic carbon. XRD analysis shows that the main uranium-bearing phase is uraninite and lead is present mainly as galena. The significance of the results for nuclear fuel waste management is discussed.


1986 ◽  
Vol 82 ◽  
Author(s):  
H. E. Rhodes ◽  
G. Apai

ABSTRACTWe have studied the atomic states of arsenic (As) and phosphorus (P) in SiO2 using X-ray photoelectron spectroscopy (XPS). Silicon dioxide implanted with As or P shows multiple XPS core level peaks corresponding to the impurity atoms located in two distinct atomic sites. The binding energies of the two arsenic 3d core levels occur at 45.8 and 42.3 eV and the two phosphorus 2p core levels occur at 134.7 and 130.3 eV. When the implanted oxides are annealed in an oxygen ambient between 900°C and 950°C, only the highbinding- energy peaks of P and As are observed. This identifies the highbinding- energy core level peaks as being associated with the impurity (P or As) on silicon sites. Annealing in nitrogen at 950° C results in an increase in the low-binding-energy signal. The low-binding-energy peaks are associated with the impurity (P or As) bonded to silicon neighbors. The relative amounts of dopants in silicon and oxygen sites depend on ambient purity and processing details. Reference to previous work shows that the presence of As or P on silicon sites in SiO2 corresponds to a fast diffusing state whereas As or P on oxygen sites corresponds to a slow diffusing state [1].


1992 ◽  
Vol 264 ◽  
Author(s):  
Pradnya V. Nagarkar ◽  
Jiong Ping Lu ◽  
David Volfson ◽  
Klavs F. Jensen ◽  
Stephen D. Senturia

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.


1987 ◽  
Vol 66 (9) ◽  
pp. 1470-1478 ◽  
Author(s):  
T. Hanawa ◽  
H. Takahashi ◽  
M. Ota ◽  
R.F. Pinizzotto ◽  
J.L. Ferracane ◽  
...  

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.


Author(s):  
S.M. Widstrand ◽  
K.O. Magnusson ◽  
L.S.O. Johansson ◽  
E. Moons ◽  
M. Gurnett ◽  
...  

We report on a high-resolution x-ray photoelectron spectroscopy (HRXPS) study using synchrotron radiation, for the identification of the core level binding energies of Ga 3d and N 1s, from a stoichiometric Ga-polar GaN(0001)-1×1 sample.Three surface shifted components were found on the stoichiometric surface for the Ga 3d feature. The first surface shifted component has a higher binding energy of 0.85 eV, and is interpreted as surface Ga with one of the N bonds replaced by an empty dangling bond. This structure is belonging to the stoichiometric clean and ordered Ga-polar GaN(0001)-1×1 surface. The second, with a binding energy relative the bulk of −0.76 eV, is interpreted as Ga with one of the bonds to a Ga atom, which indicates a slight excess of Ga on the surface. The third surface shifted component is shifted by 2.01 eV and is related to gallium oxide in different configurations.The N 1s feature is complex with five surface shifted components relative the bulk were found. Two components with binding energy shifts of −0.54 eV and 0.47 eV are interpreted as surface shifted core levels from the stoichiometric, clean Ga-polar GaN(0001)-1×1 surface.We also analysed the Ga 3d spectrum after deposition of 1.5 ML of Ga on a stoichiometric surface. The surface shift for the Ga 3d5/2 component from the Ga overlayer is −1.74 eV relative the bulk GaN.The C 1s and O 1s core levels from remaining surface contamination have also been line shaped analysed and show complex structures.


Clay Minerals ◽  
1997 ◽  
Vol 32 (4) ◽  
pp. 565-572 ◽  
Author(s):  
C. W. Childs ◽  
K. Inoue ◽  
H. Seyama ◽  
M. Soma ◽  
B. K. G. Theng ◽  
...  

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.


Sign in / Sign up

Export Citation Format

Share Document