Scattering experiments on the structure of colloidal dispersions: hexagonal layers or cubic crystals?

A description is given of how colloidal hexagonal layers and cubic crystals can be interrelated. The experimental preparation of 2D layers by shear, t heir recrystallization to form 3D crystals, and the scattering of light, ne utrons and Xrays by these structures are considered. The scattering intensi ty is best described by Bragg rods. It turns out that the transition from 2 D layers to 3D crystals leads to an intensity redistribution along certain Bragg rods which allows the crystallization kinetics to be investigated.