Stability of Binary Colloidal Crystals Immersed in a Cholesteric Liquid Crystal

In this paper, we model a number of both closed-packed and non-closed-packed crystals inside a cholesteric liquid crystal (LC) with different pitch values and nematic LC through the Landau--de Gennes free-energy method. We used binary boundary conditions (normal and planar anchoring) applied on the surface of colloids as we are interested in investigating the stability of binary crystals. The results indicate that body-centered-cubic (BCC) crystals have a lower-energy lattice defect structure than the diamond crystal, and the most energetically favorable BCC lattice can be formed in a cholesteric liquid crystal with a pitch value commensurate with the lattice spacing. Furthermore, it is shown that a pair of binary colloids can be self-assemble into a stable face-centered-cubic lattice structure inside a nematic LC, as it has the lowest energy comparing to diamond and BCC crystals.