Three-body forces at work: Three-body potentials derived from triplet correlations in colloidal suspensionsC. Russ1, M. Brunner2, C. Bechinger2 and H. H. von Grünberg3
1 Universität Konstanz, Fachbereich Physik - D-78457 Konstanz, Germany
2 Universität Stuttgart, 2. Physikalisches Institut - D-70550 Stuttgart, Germany
3 Karl-Franzens Universität Graz, Institut für Chemie - A-8010 Graz, Austria
received 13 September 2004; accepted in final form 12 November 2004
published online 24 December 2004
Two- and three-particle correlation functions are computed from video-microscopy data of two-dimensional suspensions of charged colloids and inverted to derive the pair and three-body interaction potentials between the colloidal particles. Our method allows to resolve the full spatial dependence of the three-body potentials. Examining colloidal systems at different colloid densities, we find density-independent, attractive three-body potentials, with a minimum of a few kT that is most pronounced in the equilateral triangle configuration.
82.70.Dd - Colloids.
82.70.-y - Disperse systems; complex fluids.
05.20.Jj - Statistical mechanics of classical fluids.
© EDP Sciences 2005