Accession Number : ADA321671

Title :   Application of a Novel Differential XAFS Approach for Determination of Coordination Geometries.

Descriptive Note : Technical rept.,

Corporate Author : GEORGE WASHINGTON UNIV WASHINGTON DC DEPT OF CHEMISTRY

Personal Author(s) : Ramaker, D. E. ; Sambe, H. ; Qian, X. ; O'Grady, W. E.

PDF Url : ADA321671

Report Date : JAN 1997

Pagination or Media Count : 5

Abstract : A novel differential XAFS approach has been developed which allows the determination of small distortions in coordination geometry (distortions in bond lengths and angles) about the absorber. The approach requires taking the difference, delta-X, between the XAFS of the sample and a reference material. The Fourier transform of delta-X directly reveals the average of the altered path lengths between the sample and the reference. More importantly, the amplitude of delta-X directly reflects the magnitude of the changes in the bond lengths or angles. FEFF6 calculations verify this approach, and help to interpret the data. Application of this technique has been made to the zincate ion in an alkaline Zn battery, where small distortions from the Td geometry, resulting from ion pair interactions can be determined directly.

Descriptors :   *SYSTEMS APPROACH, *DISTORTION, *X RAY ABSORPTION ANALYSIS, FOURIER TRANSFORMATION, PATHS, LENGTH, ZINC, BONDING, DETERMINATION, ION ION INTERACTIONS.

Subject Categories : Physical Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE