title: Enhancement of the chemical stability in confined δ-Bi2O3.
abstract: Bismuth-oxide-based materials are the building blocks for modern ferroelectrics, multiferroics, gas sensors, light photocatalysts and fuel cells. Although the cubic fluorite δ-phase of bismuth oxide (δ-Bi2O3) exhibits the highest conductivity of known solid-state oxygen ion conductors, its instability prevents use at low temperature. Here we demonstrate the possibility of stabilizing δ-Bi2O3 using highly coherent interfaces of alternating layers of Er2O3-stabilized δ-Bi2O3 and Gd2O3-doped CeO2. Remarkably, an exceptionally high chemical stability in reducing conditions and redox cycles at high temperature, usually unattainable for Bi2O3-based materials, is achieved. Even more interestingly, at low oxygen partial pressure the layered material shows anomalous high conductivity, equal or superior to pure δ-Bi2O3 in air. This suggests a strategy to design and stabilize new materials that are comprised of intrinsically unstable but high-performing component materials.
authors: Department of Energy Conversion and Storage, Technical University of Denmark, DTU Risø Campus, DK-4000 Roskilde, Denmark.
authors: Simone
authors: S
authors: Sanna
authors: Department of Energy Conversion and Storage, Technical University of Denmark, DTU Risø Campus, DK-4000 Roskilde, Denmark.
authors: Vincenzo
authors: V
authors: Esposito
authors: Department of Energy Conversion and Storage, Technical University of Denmark, DTU Risø Campus, DK-4000 Roskilde, Denmark.
authors: Jens Wenzel
authors: JW
authors: Andreasen
authors: Department of Energy Conversion and Storage, Technical University of Denmark, DTU Risø Campus, DK-4000 Roskilde, Denmark.
authors: Johan
authors: J
authors: Hjelm
authors: Department of Energy Conversion and Storage, Technical University of Denmark, DTU Risø Campus, DK-4000 Roskilde, Denmark.
authors: Wei
authors: W
authors: Zhang
authors: Center for Electron Nanoscopy, Technical University of Denmark Lyngby Campus, DK-2800 Kgs. Lyngby, Denmark.
authors: Takeshi
authors: T
authors: Kasama
authors: Department of Energy Conversion and Storage, Technical University of Denmark, DTU Risø Campus, DK-4000 Roskilde, Denmark.
authors: Søren Bredmose
authors: SB
authors: Simonsen
authors: Center for Materials Crystallography, Department of Chemistry &iNANO, Aarhus University, DK-8000 Aarhus C, Denmark.
authors: Mogens
authors: M
authors: Christensen
authors: Department of Energy Conversion and Storage, Technical University of Denmark, DTU Risø Campus, DK-4000 Roskilde, Denmark.
authors: Søren
authors: S
authors: Linderoth
authors: Department of Energy Conversion and Storage, Technical University of Denmark, DTU Risø Campus, DK-4000 Roskilde, Denmark.
authors: Nini
authors: N
authors: Pryds