Microstructure formation in charged sphere colloidal crystals after heterogeneous nucleation

以前的工作已经揭示了基于壁的带电球胶体晶体的不同微观结构，包括孪生单片晶体、半球形帽、生长和平衡面、枝晶和不同形式的过度生长。我们在此建议通过各种微观方法来研究这些，这些方法可以获得晶体形状，结构，晶格平面的方向以及混合物的组成。重点将放在两种不同的晶体在同时凝固过程中竞争的情况下（双畴、共存的bcc和fcc晶体、共晶），并可能受到实验边界条件（重力、粒子壁相互作用、盐梯度）的影响。除了这些自组织的微观结构，我们还将尝试通过微接触印刷来操纵晶体种类的分布。

Previous work has revealed a zoo of different microstructures of wall based charged sphere colloidal crystals including twinned monolithic crystals, hemispherical caps, growth and equilibriumm facets, den-drites, and different forms of overgrowth. We here propose to study these by various microscopic meth-ods, which give access to crystal shapes, structure, orientation of lattice planes and for mixtures also to composition. Focus will be on situations in which two different crystal species compete during simultane-ous solidification (twin domains, coexisting bcc and fcc crystals, eutectics) and may be influenced by experimental boundary conditions (gravity, particle wall interaction, salt gradients). Beyond these self organized microstructures we will also try to manipulate the distribution of crystal species via micro-contact printing.