Three-body forces at work: Three-body potentials derived from triplet correlations in colloidal suspensions

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.

[1]  R. Rzehak,et al.  Poisson–Boltzmann Brownian dynamics of charged colloids in suspension , 2004, 0801.3913.

[2]  J. Dobnikar,et al.  Three-body interactions in colloidal systems. , 2004, Physical review. E, Statistical, nonlinear, and soft matter physics.

[3]  Clemens Bechinger,et al.  Direct measurement of three-body interactions amongst charged colloids. , 2004, Physical review letters.

[4]  C. Bechinger,et al.  Measuring the equation of state of a hard-disc fluid , 2003, cond-mat/0305652.

[5]  G. Maret,et al.  Three-particle correlations in simple liquids. , 2003, Physical review letters.

[6]  J. Dobnikar,et al.  Effect of many-body interactions on the solid-liquid phase behavior of charge-stabilized colloidal suspensions , 2002, cond-mat/0209162.

[7]  M. Dijkstra,et al.  Three-body forces between charged colloidal particles. , 2002, Physical review. E, Statistical, nonlinear, and soft matter physics.

[8]  C. Bechinger,et al.  Density-dependent pair interactions in 2D , 2002 .

[9]  E. Verwey,et al.  Theory of the stability of lyophobic colloids. , 1955, The Journal of physical and colloid chemistry.