![]() We have found that in a system of long-range repulsive colloids, a simple one-dimensional (1D) substrate pattern consisting of equally spaced lines induces a variety of 3D colloidal structures. The figure shows a 2D coordinate autocorrelation graphs (probing correlations between particle coordinates) for a system exhibiting a 1D ordered surface plane (line spacing = 2.26mm, f = 0.24). Successive images indicate correlations in (a) the surface layer, (b) layer four and five with coordinates from both layers projected onto a single plane (which causes the frequency doubling compared to (a)), and (c) a depth of 15 µm using again a two-layer projection. The color table is given on the right (blue = 0, white = 1). The inset in (a) shows a confocal image of the surface layer to demonstrate the buckling of particles; the lines that make up the substrate pattern are visible as well in the inset. The dashed lines in (c) indicate the two in-plane lattice-directions, deviating slightly from 90 degrees due to the stress present in the crystal. |
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modified: 25-04-2018, 12.37 |