X‐ray diffraction and x‐ray absorption studies of porous silicon, siloxene, heat‐treated siloxene, and layered polysilane

1994 ◽  
Vol 75 (4) ◽  
pp. 1946-1951 ◽  
Author(s):  
J. R. Dahn ◽  
B. M. Way ◽  
E. W. Fuller ◽  
W. J. Weydanz ◽  
J. S. Tse ◽  
...  
Keyword(s):  
Porous Silicon ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heat Treated ◽  
Absorption Studies ◽  
X Ray Absorption

Characterization and Dissolution of ZrTh3UO10 and Th3UO8 Ceramics

2002 ◽  
Vol 713 ◽  
Author(s):  
Gini Curran ◽  
Yoann Sevestre ◽  
Wendy Rattray ◽  
Patrick G. Allen ◽  
Ken R. Czerwinski
Keyword(s):  
Oxidation State ◽  
X Ray Diffraction ◽  
X Ray ◽  
Uranium Oxidation ◽  
Absorption Studies ◽  
The Matrix ◽  
Microscopy Techniques ◽  
Long Term Behavior ◽  
Electron Energy Loss ◽  
X Ray Absorption

ABSTRACTThoria-urania-zirconia ceramics were studied in order to investigate the long-term behavior of potential thorium fuels in a repository environment. The ceramics were prepared by coprecipitation of the metal salts. Zirconia was added to determine if further stabilization against dissolution of the thoria-urania system could be achieved. In addition, 0.5 wt% MgO was added to some samples to increase stability and density. The inclusion of Zr in the ceramics did not dramatically decrease the leaching of thorium from the matrix.Material properties of the ceramic were analyzed using electron microscopy techniques such as Energy Dispersive X-ray (EDX) analysis and Electron Energy Loss Spectroscopy (EELS). X-ray diffraction and synchrotron-based x-ray absorption studies including extended xray fine structure (EXAFS) and x-ray absorption near edge spectroscopy (XANES) were also used to reveal elements of the phase structure and chemistry of the ceramics. X-ray diffraction (XRD) and EDX show that these ceramics separate into a zirconium-based phase and an actinide-based phase with low mutual affinity of thorium and zirconium, as well as partial solubilization of uranium in zirconium. The comparison of EELS spectra collected for the ceramics with spectra collected for UO2 and U3O8 reference materials also allow the assessment of uranium oxidation state independently in the two separate phases. Assessment of the bulk oxidation state using XANES correlated well with the EELS analysis. Interatomic distances and the bulk crystal structure were determined using EXAFS.

Operando X-ray diffraction and X-ray absorption studies of the structural transformation upon cycling excess Li layered oxide Li[Li1/18Co1/6Ni1/3Mn4/9]O2 in Li ion batteries

2015 ◽  
Vol 3 (16) ◽  
pp. 8613-8626 ◽  
Author(s):  
Ching-Hsiang Chen ◽  
Chun-Jern Pan ◽  
Wei-Nien Su ◽  
John Rick ◽  
Chih-Jen Wang ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Li Ion Batteries ◽  
X Ray Diffraction ◽  
Lithium Ions ◽  
X Ray ◽  
Oxygen Ions ◽  
Surface Electronic Structure ◽  
Absorption Studies ◽  
Li Ion ◽  
X Ray Absorption

Co helps maintain the lithium ions stably in the transition metal inter slabs and the surface electronic structure of oxygen ions is reversible during cycling between 4.6 V and 2.5 V.

In Situ X-Ray Absorption Studies of the Electrochemical Reduction of Hydroxocobalamin

1997 ◽  
Vol 7 (C2) ◽  
pp. C2-619-C2-620 ◽  
Author(s):  
M. Giorgett ◽  
I. Ascone ◽  
M. Berrettoni ◽  
S. Zamponi ◽  
R. Marassi
Keyword(s):  
Electrochemical Reduction ◽  
X Ray ◽  
Absorption Studies ◽  
X Ray Absorption

Effect of trytophan as dopant on potassium acid phthalate single crystals

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Single Crystals ◽  
Room Temperature ◽  
Visible Region ◽  
X Ray Diffraction ◽  
X Ray ◽  
Slow Evaporation Technique ◽  
Absorption Studies ◽  
Evaporation Technique ◽  
Potassium Acid Phthalate ◽  
Acid Phthalate

Optically transparent single crystals of potassium acid phthalate (KAP, 0.5 g) 0.05 g and 0.1 g (1 and 2 mol %) trytophan were grown in aqueous solution by slow evaporation technique at room temperature. Single crystal X- ray diffraction analysis confirmed the changes in the lattice parameters of the doped crystals. The presence of functional groups in the crystal lattice has been determined qualitatively by FTIR analysis. Optical absorption studies revealed that the doped crystals possess very low absorption in the entire visible region. The dielectric constant has been studied as a function of frequency for the doped crystals. The thermal stability was evaluated by TG-DSC analysis.

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