Dynamics of Dislocations in a Two Dimensional Block Copolymer System with Hexagonal Symmetry

A.D. PEZZUTTI; D.A. VEGA; M.A VILLAR

PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES

ROYAL SOC

Lugar: Londres, U.K.; Año: 2011 vol. 369 p. 335 - 350

1364-503X

Block copolymer thin films have attracted considerable attention for their ability toself-assemble into nanometre-scale architectures. Recent advances in the use of blockcopolymer thin films as nano-lithographic masks have driven research efforts in order tohave better control of long-range ordering in the plane of the film. Irrespective of themethod of sample preparation, different quasi-two-dimensional systems with hexagonalsymmetry unavoidably contain translational defects, called dislocations. Dislocationscontrol the process of coarsening in the nano/meso-scales and provide one of the mostimportant mechanisms of length-scale selection in hexagonal patterns. Although inthe last decade the nonlinear dynamics of topological defects in quasi-two-dimensionalsystems has witnessed significant progress, still little is known about the role of externalfields on the creation and annihilation mechanisms involved in the relaxation processtowards equilibrium states. In this paper, the dynamics of dislocations in non-optimalhexagonal patterns is studied in the framework of the Ohta–Kawasaki model for a diblockcopolymer. Measurements of the climb and glide velocities as a function of the wavevector deformation reveal the main mechanisms of relaxation associated with the motionof dislocations.