title: New epitaxial phase transition between DG and HEX in PS-b-PI.
abstract: We investigated the epitaxial phase transition from double gyroid (DG) to hexagonally packed cylinder (HEX) phases of a polystyrene-b-polyisoprene diblock copolymer in a thin film on a Si wafer substrate. The internal structure of the thin film was investigated by grazing incidence small-angle X-ray scattering, transmission electron microscopy, and transmission electron microtomography (TEMT). TEMT allows observation of the 3D-image of coexisting DG and HEX directly. Good domain orientation in the thin film and direct 3D-imaging of TEMT made it possible to observe the coexisting phase of DG and HEX, and a new epitaxial transition path from DG to HEX was found.
authors.affiliation: Department of Chemistry and Polymer Research Institute, Pohang University of Science and Technology, Pohang, 790-784, Korea.
authors.forename: Hae-Woong
authors.initials: HW
authors.lastname: Park
authors.forename: Jueun
authors.initials: J
authors.lastname: Jung
authors.forename: Taihyun
authors.initials: T
authors.lastname: Chang
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Matsunaga
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Jinnai