Probing the local structure of liquid binary mixtures by x-ray absorption spectroscopy

Local structure of binary mixtures has been usually determined by diffraction techniques. In the past few years the analysis of x-ray absorption spectroscopy data has been proved to be a powerful tool for an accurate determination of the structure of solid and liquid systems, complementary to x-ray or neutron scattering methods. In this paper we report about a procedure to extract pair correlation functions of liquid and disordered binary mixtures from x-ray absorption fine structure (XAFS) data, satisfying both long-distance behavior and long wavelength limit of Bhatia-Thornton structure factors. An application to accurate XAFS data collected on a CuSn binary metal alloy (Cu6Sn5) is reported and compared with existing models.