Surface reconstruction of an ordered fluid: An analogy with crystal surfaces - art. no. 035505

The surface structure of a lamellar polystyrene-block-polybutadiene-block-p olymethylmethacrylate (SBM) triblock copolymer forms a complex reconstructi on, which breaks the two-dimensional continuous translational symmetry of a n ideal (homogeneous) SBM surface. Despite the very different types of matt er and order, our findings reveal a remarkable analogy with the well-known phenomenon of surface reconstruction of single crystals, in particular, wit h the (2 x 1) "buckling row" reconstruction of the Si(100) surface. Similar ities and differences between both classes of materials are discussed on th e basis of symmetry considerations.