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arXiv · 1310.8198

Two-dimensional colloidal mixtures in magnetic and gravitational fields

Hartmut Löwen·Tobias Horn·Tim Neuhaus·Borge ten Hagen
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Abstract

This mini-review is concerned with two-dimensional colloidal mixtures exposed to various kinds of external fields. By a magnetic field perpendicular to the plane, dipole moments are induced in paramagnetic particles which give rise to repulsive interactions leading to complex crystalline alloys in the composition-asymmetry diagram. A quench in the magnetic field induces complex crystal nucleation scenarios. If exposed to a gravitational field, these mixtures exhibit a brazil--nut effect and show a boundary layering which is explained in terms of a depletion bubble picture. The latter persists for time-dependent gravity ("colloidal shaking"). Finally, we summarize crystallization effects when the second species is frozen in a disordered matrix which provides obstacles for the crystallizing component.

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Hartmut Löwen, Tobias Horn, Tim Neuhaus, Borge ten Hagen. 2013-10-30. Two-dimensional colloidal mixtures in magnetic and gravitational fields. https://doi.org/10.1140/epjst%2Fe2013-02069-8

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