0000000000113643

AUTHOR

S. Bénazeth

Cu Polyimidazole Thioether Complexes : Comparison of RDF's Reconstructed from XAFS and XRD Data

Radial distribution functions (RDF) reconstructed from XAFS data (Cu K-edge at low and room temperatures) are compared with RDF's constructed from XRD crystallographic data of Cu polyimidazole thioether complexes. New EDA software package possibilities are used to reconstruct RDFs: (i) model independent RDF reconstruction, and (ii) multi shell - cumulant fitting. RDF's obtained from XRD data are broadened with Debye Waller factors calculated from XAFS. This way the structural disorder (set of distances) and thermal (vibrational) disorder are quantitatively taken into account in each RDF reconstruction approach. Within experimental error the three sets of RDF'S agree well with each other for…

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Short and Medium Range Order in Se1-xTexGlasses

Complementary XAFS measurements (LURE and NSLS) of Se 1 - x Te x glasses have been carried out on both the Se and Te K-edges 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-Se 1 , Se-Te 1 , Te-Se 1 ,and Te-Te 1 ); (ii) second shell intrachain (Se-Se 2 and Se-Te 2 ) and interchain next nearest neighbors (Se⇔Se 3 single scattering in the chains Se-Se 1 -Se 3 and Se-Te 1 -Se 3 ). For the first and second coordination shells we suggest that the intrachain chemical order increases with Te content. On the other hand, we propose a model of random distribution of Se…

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XAFS study of interchain and intrachain order inSe1−xTexglasses: Nearest neighbors

XAFS measurements (LURE and NSLS) of ${\mathrm{Se}}_{1\ensuremath{-}x}{\mathrm{Te}}_{x}$ glasses have been carried out on both the Se and Te $K$ edges at low and room temperatures. Using a multishell best-fit analysis procedure, we have reconstructed the Se and Te local environment: first-shell intrachain nearest neighbors $(\mathrm{Se}\ensuremath{-}{\mathrm{Se}}_{1}, \mathrm{Se}\ensuremath{-}{\mathrm{Te}}_{1}, \mathrm{Te}\ensuremath{-}{\mathrm{Se}}_{1},$ and $\mathrm{Te}\ensuremath{-}{\mathrm{Te}}_{1}).$ We conclude that the intrachain chemical order (preferential of Se-Te pairs) increases with Te content in the glasses. On the other hand, we suggest a random distribution of Se and Te atom…

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