2020 Impact factor 1.890
Soft Matter and Biological Physics


Eur. Phys. J. E 4, 263-271

Dynamics and correlations in magnetic colloidal systems studied by X-ray photon correlation spectroscopy

J. Lal1, D. Abernathy1, L. Auvray2, O. Diat1 and G. Grübel1

1  European Synchrotron Radiation Facility, B.P. 220 F-38043 Grenoble Cedex, France
2  Laboratoire Leon Brillouin, CEA-SACLAY, 91191-Gif-Sur-Yvette, Cedex France

jlal@anl.gov

(Received 9 August 1999 and Received in final form 26 July 2000)

Abstract
We have studied the static and dynamic behaviour of magnetic colloidal systems (ferrofluids) by Small-Angle X-ray Scattering (SAXS) and X-ray Photon Correlation Spectroscopy (XPCS). The main features of the novel XPCS technique will be illustrated by data taken on a model system, colloidal silica spheres. We will then present the results obtained on an optically opaque suspension of magnetic colloids (maghemite) in the wave vector range from 10-3 to $10^{-2}{\AA^{-1}}$. Translational diffusion in zero field and anisotropic diffusion under external magnetic fields will be discussed.

PACS
61.10.Eq - X-ray scattering (including small-angle scattering).
82.70.Dd - Colloids.
83.10.Pp - Particle dynamics.


© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2001