Temperature-Dependent EXAFS Study on Supported Silver and Palladium Clusters

Abstract
Temperature-dependent Ag and Pd K-edge EXAFS (extended X-ray absorption fine structure) spectra were measured for SiO2-supported small Ag and Pd metal clusters. EXAFS analysis using the cumulant expansion technique has revealed that the Debye temperature is significantly lower and the themal expansion coefficient is larger for the small metal clusters compared with the corresponding bulk metal. These observations can be explained by the simple concept that the surface metal atoms of the clusters have shallower and more anharmonic interatomic potentials.