Proceedings of the 9th International Conference on X-Ray Absorption Fine Structure

J. Phys. IV France 7 (1997) C2-647-C2-648
DOI: 10.1051/jp4/1997130

EXAFS Study of the Hydration Structure of Ga Aqueous Solution. Comparison of Data from two Laboratories

A. Muñoz-Páez¹, S. Díaz-Moreno¹, E. Sánchez Marcos², J. M. Martínez², R. R. Pappalardo², I. Persson³, M. Sandstrom⁴, S. Pattanaik⁴ and P. Lindquist-Reis<sup>4

1</sup>  Departmento de Química Inorgánica and ICMSE, University of Sevilla - CSIC, 41012 Sevilla, Spain
²  Departamento de Química Física, Universidad de Sevilla, 41012 Sevilla, Spain
³  Department of Chemistry SLU, Box 7015, 75007 Uppsala, Sweden
⁴  Department of Chemisty, The Royal Institute of Technology, 10044 Stockholm, Sweden

Abstract
The reliability of EXAFS data is a matter of controversy when new applications near the limit of the technique are carried out. Herewith we present results of aqueous solutions of Ga(N0₃)₃ (0.005-1.0M) and Ga(C10₄)₃ (0.5M) measured at two synchrotron sources, SRS (Daresbury, UK) and SSRL (Stanford, USA), respectively, by two independent teams (Sevilla, Spain and Uppsala-Stockholm, Sweden), and analyzed with two different software packages (XDAP and EXAFSPAK). For the first hydration sphere the fitting parameters obtained are the same (d(Ga-O_I)=1.95±0.005Å, CN=6.0±0.1). Parameters apparently corresponding to a second hydration sphere (d(Ga-O_II)=3.97±0.03Å, CN=12±2) can be refined from both sets of spectra if the XDAP package is used, but no such contribution can be found with the EXAFSPAK program package. This is a consequence of different spline fitting techniques used in the two program packages.

© EDP Sciences 1997