title: Strongly enhanced oxygen ion transport through samarium-doped CeO2 nanopillars in nanocomposite films.
abstract: Enhancement of oxygen ion conductivity in oxides is important for low-temperature (<500 °C) operation of solid oxide fuel cells, sensors and other ionotronic devices. While huge ion conductivity has been demonstrated in planar heterostructure films, there has been considerable debate over the origin of the conductivity enhancement, in part because of the difficulties of probing buried ion transport channels. Here we create a practical geometry for device miniaturization, consisting of highly crystalline micrometre-thick vertical nanocolumns of Sm-doped CeO2 embedded in supporting matrices of SrTiO3. The ionic conductivity is higher by one order of magnitude than plain Sm-doped CeO2 films. By using scanning probe microscopy, we show that the fast ion-conducting channels are not exclusively restricted to the interface but also are localized at the Sm-doped CeO2 nanopillars. This work offers a pathway to realize spatially localized fast ion transport in oxides of micrometre thickness.
authors.affiliation: Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.|Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 151-742, Korea.|Department of Physics and Astronomy, Seoul National University, Seoul 151-742, Korea.
authors.forename: Sang Mo
authors.initials: SM
authors.lastname: Yang
authors.affiliation: Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS, UK.
authors.forename: Shinbuhm
authors.initials: S
authors.lastname: Lee
authors.affiliation: Department of Electrical and Computer Engineering, Texas A&M University, College Station, Texas 77843, USA.
authors.forename: Jie
authors.initials: J
authors.lastname: Jian
authors.affiliation: Department of Electrical and Computer Engineering, Texas A&M University, College Station, Texas 77843, USA.
authors.forename: Wenrui
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Sandia National Laboratories, Albuquerque, New Mexico 87185, USA.
authors.forename: Ping
authors.initials: P
authors.lastname: Lu
authors.affiliation: Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: Quanxi
authors.initials: Q
authors.lastname: Jia
authors.affiliation: Department of Electrical and Computer Engineering, Texas A&M University, College Station, Texas 77843, USA.
authors.forename: Haiyan
authors.identifier: http://orcid.org/0000-0002-7397-1209
authors.initials: H
authors.lastname: Wang
authors.affiliation: Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 151-742, Korea.|Department of Physics and Astronomy, Seoul National University, Seoul 151-742, Korea.
authors.forename: Tae Won
authors.initials: TW
authors.lastname: Noh
authors.affiliation: Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors.forename: Sergei V
authors.identifier: http://orcid.org/0000-0001-5354-6152
authors.initials: SV
authors.lastname: Kalinin
authors.affiliation: Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS, UK.
authors.forename: Judith L
authors.initials: JL
authors.lastname: MacManus-Driscoll