Workshop on Investigations of Higher Order Correlation Functions
J. Phys. Colloques 46 (1985) C9-101-C9-106
DOI: 10.1051/jphyscol:1985912
PROBING HIGHER ORDER CORRELATION FUNCTIONS IN LIQUIDS BY XANES (X-RAY ABSORPTION NEAR EDGE STRUCTURE)
A. Bianconi1, J. Garcia1, 2, A. Marcelli1, M. Benfatto3, C.R. Natoli3 et I. Davoli41 Dipartimento di Fisica, Università "La Sapienza", 00185 Roma, Italy
2 Department of Thermology, Zaragoza University, Spain
3 I.N.F.N. Laboratori Nazionali di Frascati, 00044 Frascati, Italy
4 Dipartimento di Matematica e Fisica, Università di Camerino, 62032 Camerino, Italy
Abstract
The higher order correlation functions of local atomic distribution at metal ion sites in acqueous solutions have been probed by XANES (X ray absorption near edge structure) experiments using synchrotron radiation. Multiple scattering theory has been applied to interpret the data and we show that in these systems the expansion of the total absorption cross section in terms of contributions of higher order scattering processes is possible over a large energy range. Therefore higher order distribution functions, beyond the pair distribution function probed by EXAFS, are probed by XANES, which is shown to be a powerful method for site geometry determination in liquids and amorphous systems.