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.

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.

Photoreflectance and X-Ray Photoelectron Spectroscopy in Lt MBE GaAs

1991 ◽  
Vol 241 ◽  
Author(s):  
D. C. Look ◽  
J. E. Hoelscher ◽  
J. T. Grant ◽  
C. E. Stutz ◽  
K. R. Evans ◽  
...  
Keyword(s):  
Surface Charge ◽  
Active Layer ◽  
Photoelectron Spectroscopy ◽  
Binding Energies ◽  
Near Surface ◽  
X Ray ◽  
Molecular Beam Epitaxial ◽  
Layer Interface ◽  
Hall Effect Measurements ◽  
Good Agreement

ABSTRACTIt has recently been shown that a 1000Å cap layer of molecular beam epitaxial (MBE) GaAs grown at 200°C passivates the surface of a GaAs active layer (n≃2×1017cm−3) in the sense of reducing the free–carrier depletion which arises from surface acceptor states. The same phenomenon holds for active-layer concentrations up to 7×1018cm−3, for caps as thin as 14Å, and for either As2 or As4 anion species. In an attempt to understand these effects, we have applied photoreflectance (PR) and x–ray photoelectron spectroscopy (XPS). In general, the PR shows contributions from the surface, cap/active–layer interface, and active–layer/buffer–layer interface, because each of these regions can have a different electric field. In fact the various field strengths can be determined from Franz–Keldysh oscillations (FKO), and good agreement with Hall–effect measurements is usually found. However, for 200°C material, no PR is seen, suggesting that there is no surface charge (no surface acceptor states below the Fermi level) or at least no surface–charge modulation by the light. The XPS data, which arise only from the near–surface (∼30Å) region, show that the binding energies in the capped samples are increased (i.e., surface Fermi pinning energy decreased) by 0.2 eV with respect to those in the uncapped samples. These data are discussed in relation to a passivation model.

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.

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.

Chemical and physical characterization of C(N)-doped W–S sputtered films

2004 ◽  
Vol 19 (8) ◽  
pp. 2356-2365 ◽  
Author(s):  
A. Nossa ◽  
A. Cavaleiro
Keyword(s):  
Photoelectron Spectroscopy ◽  
Amorphous Structure ◽  
X Ray Diffraction ◽  
Load Bearing Capacity ◽  
X Ray ◽  
Sputtered Films ◽  
Different Types ◽  
N Compounds ◽  
Good Agreement

The load-bearing capacity of self-lubricating W–S films can be improved by doping with nitrogen or carbon. In this study, the chemical composition, the atomic bonding, the structure, and the surface and cross section morphologies of sputtered W–S–C(N) films were analyzed. The addition of the doping element leads to a progressive broadening of the x-ray diffraction (XRD) peaks indicating a loss of crystallinity. In W–S–N films, amorphous structure could be obtained. In W–S–C films, W–C compounds were detected in conjunction with the hexagonal WS2 phase. For the highest C contents, a nanocomposite structure, including those phases and graphite, was suggested for the film. X-ray photoelectron spectroscopy results showed different types of bonds in the W4f peak in good agreement with the XRD results, i.e., when W–C(N) compounds were indexed W–S, W–C, and W–N bonds are present in the W4f peak. For the highest C content film, the detection of C–C bond in the C1s peak confirmed the formation of graphite.

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.

A DFT study of spherands containing five anisyl groups — Highly preorganized to bind the alkali metal

2006 ◽  
Vol 84 (8) ◽  
pp. 1045-1049 ◽  
Author(s):  
Shabaan AK Elroby ◽  
Kyu Hwan Lee ◽  
Seung Joo Cho ◽  
Alan Hinchliffe
Keyword(s):  
Density Functional Theory ◽  
Binding Energy ◽  
Density Functional ◽  
Ionic Radius ◽  
Binding Energies ◽  
Cavity Size ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray ◽  
Good Agreement

Although anisyl units are basically poor ligands for metal ions, the rigid placements of their oxygens during synthesis rather than during complexation are undoubtedly responsible for the enhanced binding and selectivity of the spherand. We used standard B3LYP/6-31G** (5d) density functional theory (DFT) to investigate the complexation between spherands containing five anisyl groups, with CH2–O–CH2 (2) and CH2–S–CH2 (3) units in an 18-membered macrocyclic ring, and the cationic guests (Li+, Na+, and K+). Our geometric structure results for spherands 1, 2, and 3 are in good agreement with the previously reported X-ray diffraction data. The absolute values of the binding energy of all the spherands are inversely proportional to the ionic radius of the guests. The results, taken as a whole, show that replacement of one anisyl group by CH2–O–CH2 (2) and CH2–S–CH2 (3) makes the cavity bigger and less preorganized. In addition, both the binding and specificity decrease for small ions. The spherands 2 and 3 appear beautifully preorganized to bind all guests, so it is not surprising that their binding energies are close to the parent spherand 1. Interestingly, there is a clear linear relation between the radius of the cavity and the binding energy (R2 = 0.999).Key words: spherands, preorganization, density functional theory, binding energy, cavity size.

The Growth and Characterization of Germanium-Carbon Alloy Thin Films

1992 ◽  
Vol 270 ◽  
Author(s):  
Haojie Yuan ◽  
R. Stanley Williams
Keyword(s):  
Thin Films ◽  
Photoelectron Spectroscopy ◽  
Vacuum Chamber ◽  
Optical Band Gap ◽  
High Vacuum ◽  
Optical Absorption Spectroscopy ◽  
Alloy Thin Film ◽  
New Materials ◽  
X Ray

ABSTRACTThin films of pure germanium-carbon alloys (GexC1−x with x ≈ 0.0, 0.2, 0.4, 0.5, 0.6, 0.8, 1.0) have been grown on Si(100) and A12O3 (0001) substrates by pulsed laser ablation in a high vacuum chamber. The films were analyzed by x-ray θ-2θ diffraction (XRD), x-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), conductivity measurements and optical absorption spectroscopy. The analyses of these new materials showed that films of all compositions were amorphous, free of contamination and uniform in composition. By changing the film composition, the optical band gap of these semiconducting films was varied from 0.00eV to 0.85eV for x = 0.0 to 1.0 respectively. According to the AES results, the carbon atoms in the Ge-C alloy thin film samples has a bonding configuration that is a mixture of sp2 and sp3 hybridizations.

Monitoring and characterization of creation of geopolymers prepared from fly ash and metakaolin by X-ray photoelectron spectroscopy method

2014 ◽  
Vol 34 (3) ◽  
pp. 841-849 ◽  
Author(s):  
M. Kanuchova ◽  
L. Kozakova ◽  
M. Drabova ◽  
M. Sisol ◽  
A. Estokova ◽  
...  
Keyword(s):  
Fly Ash ◽  
Photoelectron Spectroscopy ◽  
Spectroscopy Method ◽  
X Ray
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