Unraveling Exafs Spectroscopy

Fay, Martin J.; Proctor, Andrew; Hoffmann, Douglas P.; Hercules, David M.

doi:10.1021/ac00172a737

Cited by 21 publications

(9 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Such a statement has been based on the fact that the main EXAFS oscillation appears at higher energy when the bond is shorter. 40 The phenomenon presumably originates from the fact that the hydrated potassium and cesium ions are smaller than hydrated sodium and lithium cations. We assume that alkali metal cations enter the system's lattice in the hydrated form.…”

Section: Resultsmentioning

confidence: 99%

Electrochemical Charging, Countercation Accommodation, and Spectrochemical Identity of Microcrystalline Solid Cobalt Hexacyanoferrate

et al. 1998

View full text Add to dashboard Cite

Oxidized and reduced cobalt(II) hexacyanoferrates were fabricated and characterized in the presence of alkali metal (Li+, Na+, K+, Cs+) and Co2+ countercations. Formal potentials of hexacyanoferrate(III,II) redox reactions are sensitive to the choice of electrolyte cation, and they correlate well with the sizes of hydrated Li+, Na+, and K+. Electrochemical quartz crystal microbalance measurements clearly indicate that countercations, presumably in partially dehydrated form, are incorporated into reduced cobalt(II) hexacyanoferrate(II). The color of the system reflects primarily the oxidation state of iron sites. But the color of the reduced form is also affected by the nature of an intercalated hydrated countercation. This observation is correlated with the reversible continuous thermochromism of K2CoII[FeII(CN)6]*nH2O that shall be attributed to the release of structural water molecules interacting with CoII during heating in the temperature range 25−85 °C. It is apparent from X-ray absorption near-edge structure (XANES) experiments that the chemical environment of cobalt(II) sites is influenced by the presence of hydrated alkali metal countercations. The results are consistent with the accommodation of countercations in the lattice cavities at interstitial positions. The structural environment of iron ions was the same in all systems studied except that a chemical shift was observed due to change of the oxidation state of iron.

show abstract

Section: Resultsmentioning

confidence: 99%

Electrochemical Charging, Countercation Accommodation, and Spectrochemical Identity of Microcrystalline Solid Cobalt Hexacyanoferrate

et al. 1998

View full text Add to dashboard Cite

show abstract

“…Researchers are currently investigating both instrumental and wetchemical analytical methods. Instrumental approaches, such as laser microprobe mass spectrometry (LAMMS) (16) or extended X-ray absorption fine structure (EXAFS) and related X-ray absorption near-edge structure (XANES) spectroscopies (17), focus on characteristics of atoms, less often molecules, while examining very small areas of the sample to the depth of only a few micrometers. This limitation can cause problems during calibration and speciation as minute amounts of airborne dust often are not distributed uniformly on collection filters.…”

Section: Introductionmentioning

confidence: 99%

“…Several methods have been proposed and/or are currently used to remove hazardous chemicals from contaminated waters, for example, carbon adsorption (7-12), oxidation using ozone (13,14), and aeration stripping (15)(16)(17)(18)(19). All of the above processes have been and are being used.…”

Section: Introductionmentioning

confidence: 99%

Chemical speciation of nickel in airborne dusts: analytical method and results of an interlaboratory test program

Zatka¹,

Warner²,

Maskery³

1992

Environ. Sci. Technol.

View full text Add to dashboard Cite

“…Electron diffraction techniques such as low-energy electron diffraction (DEED) can provide surface structural information. The wider availability of synchrotron radiation sources has provided options for analysis of other forms of local surface structure through the use of extended X-ray absorption fine structure (EXAFS) and related spectroscopies (3,4).…”

mentioning

confidence: 99%

Quantitation of Auger and x-ray photoelectron spectroscopies

Nebesny¹,

Maschhoff²,

Armstrong³

1989

Anal. Chem.

View full text Add to dashboard Cite

Surface analysis using electron spectroscopies is now a well-established and continuously expanding area. With appropriate data treatment procedures, both Auger electron spectroscopy (AES, not to he confused with atomic emission spectroscopy) and Xray photoelectron spectroscopy (XPS or ESCA) can routinely supply reliable with binding energies of less than loo0 eV. The kinetic energy of the electron escaping the solid and successfully traversing the analyzer to the detector is specific to the element of origin and is further varied by changes in the oxidation state of that element. Shifts in spectral lines are sizable in both AES and XPS, hut more easily interpreted for XPS. Molecular information about the solid can generally he obtained together with its elemental makeup and an estimate of concentration.Since the development of the first modern commercial surface spectrometers in the late 1960s and early 1970s, there has been a steady refinement and improvement in the instrumentation for surface electron spectroscopies (see qualitative and semiquantitative characterization of the near-surface region (top 1-100 A) of most solids.A schematic of the spectroscopic processes is shown in Figure 1 (using the S(2p) photoemission (XPS) and S (LMM) Auger emission as examples).Both XPS and AES typically involve ionization of core and valence electrons

show abstract

Unraveling Exafs Spectroscopy

Cited by 21 publications

References 48 publications

Electrochemical Charging, Countercation Accommodation, and Spectrochemical Identity of Microcrystalline Solid Cobalt Hexacyanoferrate

Electrochemical Charging, Countercation Accommodation, and Spectrochemical Identity of Microcrystalline Solid Cobalt Hexacyanoferrate

Chemical speciation of nickel in airborne dusts: analytical method and results of an interlaboratory test program

Quantitation of Auger and x-ray photoelectron spectroscopies

Contact Info

Product

Resources

About