Layering transitions in colloidal crystal thin films between 1 and 4 monolayers

This paper investigates the sequence of morphological transitions in a nearly hard particle arrangement of colloidal crystals confined in a wedge cell. Earlier studies have shown intermediate particle arrangements (such as the buckling, rhombic, prismatic, and hcp like phases) to account for the drastic changes in the filling fraction values between the triangular and square arrangements. However, to the best of our knowledge, there is no complete description of the transitions between n and n + 1 layers. Here we describe the ordering of the particles for films between 1 and 4 layers. We also present a new intermediate phase hcp(011) to show the transition between n square -> n Delta for n > 2 layers.