title: Defect removal in the course of directed self-assembly is facilitated in the vicinity of the order-disorder transition.
abstract: The stability of prototypical defect morphologies in thin films of symmetric diblock copolymers on chemically patterned substrates is investigated by self-consistent field theory. The excess free energy of defects and barriers of defect-removal mechanisms are obtained by computing the minimum free-energy path. Distinct defect-removal mechanisms are illustrated demonstrating that (i) defects will become unstable at a characteristic value of incompatibility χN* above the order-disorder transition and (ii) the kinetics is accelerated at weak segregation. Numerical findings are placed in the context of physical mechanisms, and implications for directed self-assembly are discussed.
authors.affiliation: Institute for Theoretical Physics, Georg-August University, 37077 Göttingen, Germany and State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai 200433, China.
authors.forename: Weihua
authors.initials: W
authors.lastname: Li
authors.affiliation: Institute for Molecular Engineering, University of Chicago, Illinois 60637, USA and Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: Paul F
authors.initials: PF
authors.lastname: Nealey
authors.affiliation: Institute for Molecular Engineering, University of Chicago, Illinois 60637, USA and Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: Juan J
authors.initials: JJ
authors.lastname: de Pablo
authors.affiliation: Institute for Theoretical Physics, Georg-August University, 37077 Göttingen, Germany.
authors.forename: Marcus
authors.initials: M
authors.lastname: Müller
mesh_terms: D008956:Models, Chemical; D011108:Polymers / Q000737:chemistry*; D013816:Thermodynamics
chemical_list: D011108:Polymers