Triplet correlations in two-dimensional colloidal model liquids

Abstract

Three-body distribution functions in classical fluids have been theoretically investigated many times, but have never been measured directly. We present experimental three-point correlation functions that are computed from particle configurations measured by means of video-microscopy in two types of quasi-two-dimensional colloidal model fluids: a system of charged colloidal particles and a system of paramagnetic colloids. In the first system the particles interact via a Yukawa potential, in the second via a potential $\Gamma /r^3$. We find for both systems very similar results: on increasing the coupling between the particles one observes the gradual formation of a crystal-like local order due to triplet correlations, even though the system is still deep inside the fluid phase. These are mainly packing effects as is evident from the close resemblance between the results for the two systems having completely different pair-interaction potentials.

many pages, 8 figures, contribution to the special issue in J.Phys. Cond. Mat. of the CECAM meeting in LYON ''Many-body....''

References in corpus (2)

• Three-Particle Correlations in Simple Liquids
• Triplet correlations in two-dimensional colloidal model liquids

Cited by in corpus (6)

• Volume terms for charged colloids: a grand-canonical treatment
• Nonlinear screening and gas-liquid separation in suspensions of charged colloids
• Triplet correlations in two-dimensional colloidal model liquids
• Effective triplet interactions in nematic colloids
• Investigation of the degree of local structural similarity between the parent-liquid and children-crystal states for a model soft matter system
• Structure of the simple harmonic-repulsive system in liquid and glassy states studied by the triple correlation function