Epitaxial crystal growth of charged colloids.

A pattern of repulsive, charged lines is shown to direct three-dimensional (3D) crystallization in a system of long-range repulsive, density-matched colloids. At volume fractions where the bulk phase behavior leads to bcc crystallization, the 1D template was found to induce formation of a metastable fcc crystal. The bcc crystals were oriented with the (100) or the (110) plane, with twofold twinning, parallel to the template. The template further induced prefreezing of the (100) plane. At a large mismatch between template and interparticle spacing, 1D strings form in the surface layer of a 3D crystal.