Structure and tracer-diffusion in quasi–two-dimensional and strongly asymmetric magnetic colloidal mixtures

• DOI: 10.1209/epl/i2002-00458-0
• Publication Date: 2003-12-23T10:43:22Z
• Authors: M Kollmann; R Hund; B Rinn; G Nägele; K Zahn; H König; G Maret; R Klein; J. K. G Dhont
• Keywords: Chemical physics and physical chemistry; info:eu-repo/classification/pacs/82.70.Dd, 05.40.Jc, 05.10.Gg; 0103 physical sciences; Computational physics; liquids and polymers; Statistical physics and nonlinear systems; Soft matter; info:eu-repo/classification/ddc/530; 01 natural sciences

We study theoretically and experimentally static and diffusional properties of a strongly asymmetric binary mixture of super-paramagnetic colloids confined to an air-water interface. The colloids interact via repulsive dipolar forces, induced by a magnetic field applied perpendicular to the planar interface. Brownian dynamics (BD) computer simulations are employed to analyse the microstructure and the tracer-diffusion of both components. The profound interaction asymmetry leads to unusual features in the partial pair distribution functions, and to significantly enhanced tracer-diffusion. We find good agreement between our experimental data and the computer simulation results.