The structure of the niobium oxide on alumina surface was investigated for low loading (5 wt.-%) and high loading (19 wt.-%) samples. The TPD profile of water molecules showed the appearance of water adsorption sites other than those on alumina. The XANES and EXAFS spectra clearly showed that niobic acid-like species are formed on the surface of 19 wt.-% NbO,/Al,O,. The XANES spectra of 5 wt.-%...

We shed light on the specific hydration structure around a zinc ion of nanosolution restricted in a cylindrical micropore of single-wall carbon nanotube (SWNT) by comparison with the structure restricted in a cylindrical mesopore of multi-wall carbon nanotube (MWNT) and that of bulk aqueous solution. The average micropore width of open-pore SWNT was 0.87 nm which is equivalent to the size of a ...

PrBa2Cu3O7 (PBCO) is unique in the RBa2Cu3O7 (R=rare earth) series because it is not superconducting. In fact, for Y1−xPrxBa2Cu3O7, Tc drops monotonically with Pr concentration, with Tc going to zero at ∼55% Pr. There have been many studies of this material with the hope that an explanation for the lack of superconductivity in PBCO might help explain why YBa2Cu3O7 (YBCO) is superconducting. Exp...

IFEFFIT, an interactive program and scriptable library of XAFS algorithms is presented. The core algorithms of AUTOBK and FEFFIT have been combined with general data manipulation and interactive graphics into a single package. IFEFFIT comes with a command-line program that can be run either interactively or in batch-mode. It also provides a library of functions that can be used easily from C or...

Contamination of vadose zone sediments under tank BX-102 at the Hanford site, Washington, resulted from the accidental release of 7-8 metric tons of uranium dissolved in caustic aqueous sludge in 1951. We have applied synchrotron-based X-ray spectroscopic and diffraction techniques to characterize the speciation of uranium in samples of these contaminated sediments. UIII-edge X-ray absorption f...

The arseniasis in Southwest Guizhou, China has been identified as a unique case of endemic arseniasis caused by exposure to indoor combustion of high As-content coal. Present investigation targeted the microdistribution and speciation of the element arsenic in human hair and environmental samples collected in one of the hyper-endemic villages of arseniasis in the area. Analyses were performed b...

X-ray Absorption Fine Structure (XAFS) spectroscopy has been widely used to characterize the short-range order of glassy materials since the theoretical basis was established 45 years ago. Soon after the technique became accessible, mainly due to the existence of Synchrotron laboratories, a wide range of glassy materials was characterized. Silicate glasses have been the most studied because the...

Complementary XAFS measurements (LURE and NSLS) of Sel,Te, glasses have been canied out on both the Se and Te Kedges at low and room temperatures. Using a multi-shell best fit analysis procedure, we have reconstructed the Se and Te local environment: (i)first shell intrachain nearest neighbors (Se-Sel, Se-Tel, Te-Se~,and Te-Tel); (ii) second shell intrachain (Se-Sez and Se-Tez) and interchain n...

We report the direct deposition of epitaxial 215-nm-thick vanadium sesquioxide (V2O3) films on aand c-plane sapphire substrates from powder-pressed V2O3 targets via pulsed-laser deposition (PLD) in an evacuated deposition chamber devoid of O2. The films were characterized using x-ray diffraction (XRD), x-ray photoemission spectroscopy (XPS), x-ray absorption fine structure (XAFS) spectroscopy, ...