title: Ultrahigh density array of epitaxial ferroelectric nanoislands on conducting substrates.
abstract: An ultrahigh density array of epitaxial PbTiO(3) (PTO) nanoislands with uniform size was fabricated on a single-crystalline Nb-doped SrTiO(3) (100) substrate over a large area (cm(2) scale) by simple but robust method utilizing polystyrene-block-poly(4-vinylpridine) copolymer micelles. Each nanoisland has an average volume of 2.6 x 10(3) nm(3) (a height of 7 nm and a diameter of 22 nm). Because of uniform nanoislands over a large area, a synchrotron X-ray diffraction experiment was successfully employed to analyze the domain structures of PTO nanoislands. They showed well-defined epitaxy on the substrate, which was also confirmed by high-resolution transmission electron microscopy. All of the nanoislands existing in the entire area showed distinct piezoresponse that confirms the existence of ferroelectricity at this size. The results indicate that the critical size of ferroelectrics could be scaled-down further, thereby much increasing the density of ferroelectric devices.
authors.affiliation: National Creative Research Initiative Center for Block Copolymer Self-Assembly and Department of Chemical Engineering, Pohang University of Science and Technology, Pohang, Kyungbuk 790-784, Korea.
authors.forename: Youngsuk
authors.initials: Y
authors.lastname: Kim
authors.forename: Hee
authors.initials: H
authors.lastname: Han
authors.forename: Yunseok
authors.initials: Y
authors.lastname: Kim
authors.forename: Woo
authors.initials: W
authors.lastname: Lee
authors.forename: Marin
authors.initials: M
authors.lastname: Alexe
authors.forename: Sunggi
authors.initials: S
authors.lastname: Baik
authors.forename: Jin Kon
authors.initials: JK
authors.lastname: Kim