Pattern Coarsening in Thin Films of Sphere-Forming Block

D.A. VEGA; L.R. GÓMEZ; C.K. HARRISON; M.L. TRAWICK; D.E. ANGELESCU; R.A. REGISTER; P.M. CHAIKIN

Bariloche

Congreso; Pan American Advanced Studies Institute on Physics at the Nanometer Scale; 2003

PASI

 The coarsening of two-dimesional hexatic patterns was stidied via cell dynamics simulations as a model for grain growh in thin flims of sphere-forming block copolymers. we compare the evolution of the density of dislocations, disclinations and the orientational correlation function. While most of the disclinations condense into dislocations and most of the dislocations condense into grain boundaries, the dynamics appears to involve the interplay between disclinations and lines of dislocations. Rather than isolated grain shrinking, the most frecuently observed process is the collapse of a smaller grain, which resides on the boundary of two larger grains. simulations results are in good agreemente with the ordering dynamics of two dimensional systems which consist of a single layer of spherical block copolymer microdomains in a thin film. Experimentally, we follow the annealing process after a quench from the disordered state by electron microscopy and time-lapse atomic force microscopy.