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

J. Phys. IV France 7 (1997) C2-261-C2-262
DOI: 10.1051/jp4/1997191

Analytical Development of the Hard-Sphere Based Radial Distribution Function for EXAFS Analysis of Disordered Compounds

E. Prouzet¹, A. Michalowicz² and N. Allali<sup>3

1</sup>  Institut des Matériaux de Nantes, UMR 110 du CNRS, 2 rue de la Houssinière, 44072 Nantes cedex 03, France
²  Faculté des Sciences et Technologies, Université Paris XII, avenue du Général de Gaulle, 94000 Créteil, France.
³  Laboratoire de Chimie Appliquée, Université Moulay Ismaïl, BP. 4010, Beni M'hamed, Meknès, Maroc

Abstract
Errors in distances and neighbors numbers are generally found when a symmetric gaussian radial distribution function (RDF) is used for fitting highly disordered compounds. Among methods used to overcome this problem, we introduced in the EXAFS equation the analytical expression of an asymmetric distances distribution based on a hard-sphere model. Such a model leads to an easy-to-handle formula that can been introduced in any fitting software. The fit gives values of R_i , the lowest distance and s, the asymmetry parameter. The effective RDF can thus be drawed b y convoluting both this distribution with the Debye-Waller gaussian broadening

© EDP Sciences 1997