Microstructure formation in charged sphere colloidal crystals after heterogeneous nucleation

以前的工作已经揭示了壁基带电球状胶体晶体的不同微观结构的动物园，包括孪晶单晶、半球帽、生长和平衡小面、黑柱石和不同形式的过度生长。我们建议用各种微观方法来研究它们，这些方法可以获得晶体的形状、结构、晶面的取向以及混合物的组成。重点将集中在两种不同的晶体物种在同时凝固过程中竞争的情况(孪晶区域、共存的体心立方和面心立方晶体、共晶)，并可能受到实验边界条件(重力、颗粒壁相互作用、盐梯度)的影响。除了这些自组织的微结构外，我们还将尝试通过微接触打印来控制晶体物种的分布。

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.