A5048791782- Radioactive element chemistry and processing
- Nuclear Materials and Properties
- Rare-earth and actinide compounds
- Fusion materials and technologies
- X-ray Spectroscopy and Fluorescence Analysis
- Nuclear materials and radiation effects
- High-pressure geophysics and materials
- Nuclear reactor physics and engineering
- Nuclear Physics and Applications
- Radioactive contamination and transfer
- Glass properties and applications
- X-ray Diffraction in Crystallography
- Ion-surface interactions and analysis
- Radioactivity and Radon Measurements
- Geochemistry and Geologic Mapping
- Thermodynamic and Structural Properties of Metals and Alloys
- Electrochemical Analysis and Applications
- Advanced Materials Characterization Techniques
- Luminescence Properties of Advanced Materials
- Physics of Superconductivity and Magnetism
- Chemical Synthesis and Characterization
- Laser-Plasma Interactions and Diagnostics
- Particle Detector Development and Performance
- Lanthanide and Transition Metal Complexes
- Diamond and Carbon-based Materials Research
Lawrence Livermore National Laboratory
2012-2024
Lawrence Berkeley National Laboratory
1996-2013
Los Alamos National Laboratory
1991-2013
Beijing Research Institute of Uranium Geology
2012
Dioxide Materials (United States)
2012
Underground Systems (United States)
2003
Lawrence Livermore National Security
2002-2003
Office of Scientific and Technical Information
2000-2003
National Technical Information Service
2000-2003
University of California, Berkeley
1996-1999
U, Np, and Pu L(II,III)-edge X-ray absorption fine structure (XAFS) spectra were collected for the UO(2)(2+), NpO(2)(+), Np(4+), Pu(3+) ions as a function of chloride concentration in aqueous solution. At low concentration, hydration numbers corresponding bond lengths different are follows: N= 5.3, R = 2.41 Å; N 5.0, 2.50 11.2, 2.40 Pu(3+), 10.2, 2.51 Å. As Cl(-) increases, inner-sphere complexation occurs, resulting decrease an expansion actinide-oxygen (water) lengths. The ion shows only...
We have used EXAFS spectroscopy to investigate the inner sphere coordination of trivalent lanthanide (Ln) and actinide (An) ions in aqueous solutions as a function increasing chloride concentration. At low concentration, hydration numbers corresponding Ln,An−O bond lengths are follows: La3+, N = 9.2, R 2.54 Å; Ce3+, 9.3, 2.52 Nd3+, 9.5, 2.49 Eu3+, 2.43 Yb3+, 8.7, 2.32 Y3+, 9.7, 2.36 Am3+, 10.3, 2.48 Cm3+, 10.2, 2.45 Å. In ca. 14 M LiCl, early Ln3+ (La, Ce, Nd, Eu) show Cl- complexation along...
ADVERTISEMENT RETURN TO ISSUEPREVarticleNEXTMultinuclear NMR, Raman, EXAFS, and X-ray diffraction studies of uranyl carbonate complexes in near-neutral aqueous solution. structure [C(NH2)3]6[(UO2)3(CO3)6].cntdot.6.5H2OP. G. Allen, J. Bucher, D. L. Clark, N. M. Edelstein, S. A. Ekberg, W. Gohdes, E. Hudson, Kaltsoyannis, Lukens, P. Neu, Palmer, T. Reich, K. Shuh, C. Tait, B. ZwickCite this: Inorg. Chem. 1995, 34, 19, 4797–4807Publication Date (Print):September 1, 1995Publication History...
The x-ray linear dichroism of the uranyl ion (${\mathrm{UO}}_{2}^{2+}$) in uranium ${\mathit{L}}_{3}$-edge extended x-ray-absorption fine structure (EXAFS), and ${\mathit{L}}_{1}$- near-edge (XANES), has been investigated both by experiment theory. A striking polarization dependence is observed experimental XANES EXAFS for an oriented single crystal acetate dihydrate [${\mathrm{UO}}_{2}$(${\mathrm{CH}}_{3}$${\mathrm{CO}}_{2}$${)}_{2}$\ensuremath{\cdot}${2\mathrm{H}}_{2}$O], with vector...
Solid state experiments at extreme pressures (10–100 GPa) and strain rates (10 6 –10 8 s −1 ) are being developed on high energy laser facilities, offer the possibility for exploring new regimes of materials science. These solid conditions can be accessed with either shock loading or a quasi-isentropic ramped pressure drive. Velocity interferometer measurements establish conditions. Constitutive models strength under these tested by comparing 2D continuum simulations measuring perturbation...
Uranium and plutonium’s 5f electrons are tenuously poised between strongly bonding with ligand spd-states residing close to the nucleus. The unusual properties of these elements their compounds (e.g., six different allotropes elemental plutonium) widely believed depend on related attributes f-orbital occupancy delocalization for which a quantitative measure is lacking. By employing resonant X-ray emission spectroscopy (RXES) absorption near-edge structure (XANES) making comparisons specific...
The use of principal component (factor) analysis for the interpretation EXAFS spectra is described.The components derived from share mathematical properties with original spectra.As a result, abstract can be analyzed using standard methodology to yield bond distances and other coordination parameters.The number that must usually less than spectra.The method demonstrated series aqueous solutions uranyl ions.
A combination of X-ray absorption, optical luminescence, and Raman vibrational spectroscopies along with ancillary techniques such as energy dispersive scanning electron microscopy powder diffraction have been used to determine the chemical form uranium in contaminated soils from United States Department Energy's (DOE) former production facility located at Fernald, OH (30 km NW Cincinnati). The analyses described here carried out on soil samples prior application various decontamination...
Extended x-ray absorption fine structure (EXAFS) measurements have demonstrated the phase transformation from body-centered-cubic (bcc) to hexagonal-close-packed (hcp) iron due nanosecond, laser-generated shocks. The EXAFS spectra are also used determine compression and temperature in shocked iron, which consistent with hydrodynamic simulations inferred velocity interferometry. This is a direct, atomic-level, situ proof of shock-induced as opposed previous indirect based on shock-wave splitting.
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTThe Oxidation State of Ce in the Sandwich Molecule CeroceneN. M. Edelstein, P. G. Allen, J. Bucher, D. K. Shuh, C. Sofield, N. Kaltsoyannis, H. Maunder, R. Russo, and A. SellaView Author Information Chemical Sciences Division Lawrence Berkeley National Laboratory Berkeley, California 94720 Department Chemistry, University College London 20 Gordon Street, WC1H 0AJ, U.K. Cite this: Am. Chem. Soc. 1996, 118, 51, 13115–13116Publication Date...
U LIII-edge EXAFS spectra were measured for 1:1 mixtures of the uranyl ion with tartaric, malic, and citric acids. The room-temperature these demonstrate characteristic uranium−oxygen interactions UO22+ also show a U−U interaction at 3.92 Å, indicating presence dimer. On basis models proposed by Martell et al. from earlier potentiometric titration experiments, it is concluded that dimer ligand-bridged species (UO2)2(L)2, in which bridging occurs through α-hydroxyl groups polycarboxylate ligands.
The structures of the aqueous nitrate complexes Pu(IV) have been studied by extended X-ray absorption fine-structure (EXAFS) at nitric acid concentrations 3, 8, and 13 M. Systematic changes in EXAFS spectra demonstrate trends increasing ligation decreasing water as a function concentration. coordination numbers nitrogens noncoordinating oxygens are consistent with previous studies which principal species were found to be di-, tetra-, hexanitrato these solutions. nitrato appear similar...