Photon correlation spectroscopy of colloidal palladium using a coherent x-ray beam

We have used an intense coherent x-ray beam and a real time digital autocorrelator to study the low frequency dynamics of colloidal palladium in glycerol by x-ray photon correlation spectroscopy (XPCS). The translational diffusion was studied in the q range from 1.5 x 10(-3) to 6 x 10(-3) Angstrom(-1) and in the temperature range from 279 to 293 K. The measured relaxation rates were proportional to q(2) and inversely proportional to viscosity as expected for a translational diffusion process. experiment shows that XPCS can be performed in a wide time range (10(-4) to 100 s) and opens up a new opportunity for the study of the dynamics of nontransparent media.