title: Photon correlation spectroscopy: X rays versus visible light
abstract: We have performed combined dynamic light scattering (DLS) and dynamic x-ray scattering (DXS) experiments on dense colloidal suspensions. The intermediate scattering functions obtained with these two techniques are compared directly. In the case of optically index matched samples, the comparison demonstrates that DXS yields accurate and reliable results. It is shown that the hydrodynamic interaction H(q) can be determined experimentally, without taking recourse to any theoretical model, by combining DXS and DLS. The combination of the two methods probes the dynamics over more than one decade in scattering vector. Experiments on optically opaque samples, where DLS fails, demonstrate the necessity to use x rays in these systems.
authors.affiliation: Van der Waals-Zeeman Instituut, Universiteit van Amsterdam, Valckenierstraat 65-67, 1018 XE Amsterdam, The Netherlands.
authors.initials: DO
authors.lastname: Riese
authors.initials: WL
authors.lastname: Vos
authors.initials: GH
authors.lastname: Wegdam
authors.initials: FJ
authors.lastname: Poelwijk
authors.initials: DL
authors.lastname: Abernathy
authors.initials: G
authors.lastname: Grubel