X-ray photoemission spectroscopy study of hexavalent uranium compounds

Veal, B. W.; Lam, D. J.; Carnall, W. T.; Hoekstra, H.R.

doi:10.1103/physrevb.12.5651

Cited by 109 publications

(39 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This indicates that two structurally distinct uranyls may be present in the crystal structure. They also agree with the U-O bond lengths in uranyl calculated with various empirical relations expressing R U-O = f [ν 3 (UO 2 ) 2+ ] Å [12,33] from the IR spectra of uranyl vanadate minerals. These values vary approximately in the range 1.770-1.798 Å [12].…”

Section: Francevillitesupporting

confidence: 83%

Vibrational spectroscopy of selected natural uranyl vanadates

Frost

Čejka

Weier

et al. 2005

Vibrational Spectroscopy

View full text Add to dashboard Cite

Dermot (2005) range and are assigned to the doubly degenerate ν 2 modes of the (UO 2 ) 2+ units. The study of the vibrational spectroscopy of uranyl vanadates is complicated by the overlap of bands from the (VO 3 ) and (UO 2 ) 2+ units. Raman spectroscopy has proven most useful in assigning bands to these two units since Raman bands are sharp and well separated as compared with infrared bands. The uranyl vanadate minerals are often found as crystals on a host matrix and Raman spectroscopy enables their in-situ characterisation without sample preparation.

show abstract

Section: Francevillitesupporting

confidence: 83%

Vibrational spectroscopy of selected natural uranyl vanadates

Frost

Čejka

Weier

et al. 2005

Vibrational Spectroscopy

View full text Add to dashboard Cite

show abstract

“…In some lightly corroded areas, FTIR analysis showed a U-O band at higher frequency 940 cm 1 than that found at more corroded areas ¾910 cm 1 , indicating that uranium may be part of a structure similar to˛-UO 2 OH 2 . 22 In the heavily corroded areas, additional corrosion processes occur that may involve further incorporation of uranium with iron corrosion products.…”

Section: Non-corroded Steel Coupons Exposed To Uranium Speciesmentioning

confidence: 99%

Uranium association with corroding carbon steel surfaces

Eng

Halada

Francis

et al. 2003

Surface & Interface Analysis

View full text Add to dashboard Cite

We investigated the association of uranium with clean and corroded surfaces of 1010 carbon steel. Studying steel contaminated by uranium species will have an important effect on the development of methods used to clean radioactively contaminated metal waste. X-ray photoelectron spectroscopy, synchrotron infrared microspectroscopy and laboratory-based Fourier transform infrared analysis of steel surfaces exposed to uranyl nitrate showed the presence of crystallized hydrated uranyl oxides, uranyl hydroxides, iron oxyhydroxides and iron oxides. In general, heavily corroded areas physically shield the uranium species, which tended to associate spatially with hydroxyl groups and lepidocrocite. Lightly corroded areas contained uranium species with stronger axial U-O bonding. Infrared spectroscopy, Rutherford backscattering spectroscopy and energy-dispersive spectroscopy mapping analysis revealed that the uranium species are well distributed within the upper micron of the thick corrosion layer and associated more with areas of high hydroxide content. Parameters such as the concentration of uranyl nitrate solution used to expose the carbon steel coupons, the method of contamination (dipped or sprayed with dilute uranyl nitrate solution) and the degree of corrosion (accelerated corrosion before and/or after contamination) played significant roles in the distribution and nature of the uranyl hydroxide/iron oxyhydroxide corrosion products found on the surface of all coupons. These factors must be considered in the development and optimization of decontamination processes for metal waste.

show abstract

“…For U compounds, several studies have shown the influence of the U-O bond length on the XPS spectral features. It was demonstrated that the splitting of the U6p 3=2 due to ligand electric fields is determined by the U-O distance (7,8). The O1s position in a large set of alkali earth-metal uranates was also shown to be closely related to the U-O bond length (9).…”

Section: Introductionmentioning

confidence: 98%