Journal of Applied Crystallography

Volume 40, Supplement (April 2007)

Dynamics

J. Appl. Cryst. (2007). 40 (Supplement), s34-s37

Measurement of self-diffusion constant with two-dimensional X-ray photon correlation spectroscopy

A. Robert

Abstract: The X-ray photon correlation spectroscopy technique probes the slow dynamics of disordered materials, overcoming the limitations of using photon correlation spectroscopy with coherent visible light. It extends the accessible range of the modulus of the scattering vector to short wavelength density fluctuations and is not sensitive to multiple scattering. We measure here experimentally the short-time self-diffusion coefficient $D_{\rm S}$ of a charge-stabilized colloidal dispersion. It is in contradiction with theoretical models including many-body hydrodynamic interactions.

Keywords: XPCS; colloids; self diffusion; density fluctuations.