title: Dynamics of bulk fluctuations in a lamellar phase studied by coherent x-ray scattering.
abstract: Using x-ray photon correlation spectroscopy, we studied the layer fluctuations in the lamellar phase of an ionic lyotropic system. We measured the relaxation rate of in-plane (undulation) fluctuations as a function of the wave vector. Static and dynamic results obtained during the same experiment were combined to yield the values of both elastic constants of the lamellar phase (compression and bending moduli) as well as that of the sliding viscosity. The results are in very good agreement with dynamic light-scattering data, validating the use of the technique in ordered phases.
authors.affiliation: Ecole Normale Supérieure de Lyon, Laboratoire de Physique, 46 Allée d'Italie, 69364 Lyon Cedex 07, France. constantin@lps.u-psud.fr
authors.forename: Doru
authors.initials: D
authors.lastname: Constantin
authors.forename: Guillaume
authors.initials: G
authors.lastname: Brotons
authors.forename: Tim
authors.initials: T
authors.lastname: Salditt
authors.forename: Eric
authors.initials: E
authors.lastname: Freyssingeas
authors.forename: Anders
authors.initials: A
authors.lastname: Madsen