title: Origin of colossal ionic conductivity in oxide multilayers: interface induced sublattice disorder.
abstract: Oxide ionic conductors typically operate at high temperatures, which limits their usefulness. Colossal room-temperature ionic conductivity was recently discovered in multilayers of yttria-stabilized zirconia (YSZ) and SrTiO3. Here we report density-functional calculations that trace the origin of the effect to a combination of lattice-mismatch strain and O-sublattice incompatibility. Strain alone in bulk YSZ enhances O mobility at high temperatures by inducing extreme O disorder. In multilayer structures, O-sublattice incompatibility causes the same extreme disorder at room temperature.
authors.affiliation: Department of Physics & Astronomy, Vanderbilt University, Nashville, Tennessee 37235, USA. t.pennycook@vanderbilt.edu
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Pennycook
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Beck
authors.forename: Kalman
authors.initials: K
authors.lastname: Varga
authors.forename: Maria
authors.initials: M
authors.lastname: Varela
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Pennycook
authors.forename: Sokrates T
authors.initials: ST
authors.lastname: Pantelides