EXAFS studies of bimetallic palladium-cobalt nanoclusters using Molecular Dynamics simulations

Structural properties of model palladium-cobalt clusters with various composition have been analysed. Their structure is optimised using Sutton-Chen potentials and Monte-Carlo procedure. Radial distribution functions and extended X-ray absorption fine structure (EXAFS) spectra were averaged over atomic configurations along Molecular Dynamics (MD) run. Applicability of the cumulant expansion method for studies of such nanoclusters is discussed. It has been found that shape of EXAFS oscillations of Pd K-edge in the k range 5-8 Å−1 strongly depends on composition of a cluster. The same effect is visible for EXAFS spectra of Co K-edge in the range 4-7 Å−1. These results are compared to the experimental data obtained for the sample of 50 at.%Pd-50 at.%Co supported on silica.