Anisotropic Proton and Oxygen Ion Conductivity in Epitaxial Ba2In2O5 Thin Films
Journal article, 2017

Solid oxide oxygen ion and proton conductors are a highly important class of materials for renewable energy conversion devices like solid oxide fuel cells. Ba2In2O5 (BIO) exhibits both oxygen ion and proton conduction, in a dry and humid environment, respectively. In a dry environment, the brownmillerite crystal structure of BIO exhibits an ordered oxygen ion sublattice, which has been speculated to result in anisotropic oxygen ion conduction. The hydrated structure of BIO, however, resembles a perovskite and the protons in it were predicted to be ordered in layers. To complement the significant theoretical and experimental efforts recently reported on the potentially anisotropic conductive properties in BIO, we measure here both the proton and oxygen ion conductivity along different crystallographic directions. Using epitaxial thin films with different crystallographic orientations, the charge transport for both charge carriers is shown to be anisotropic. The anisotropy of the oxygen ion conduction can indeed be explained by the layered structure of the oxygen sublattice of BIO. The anisotropic proton conduction, however, further supports the suggested ordering of the protonic defects in the material. The differences in proton conduction along different crystallographic directions attributed to proton ordering in BIO are of a similar extent as those observed along different crystallographic directions in materials where proton ordering is not present but where protons find preferential conduction pathways through chainlike or layered structures.

Author

A. Fluri

Paul Scherrer Institut

E. Gilardi

Paul Scherrer Institut

Maths Karlsson

Chalmers, Chemistry and Chemical Engineering, Energy and Material, Environmental Inorganic Chemistry

V. Roddatis

University of Göttingen

M. Bettinelli

Verona University

I. E. Castelli

Technical University of Denmark (DTU)

T. Lippert

Paul Scherrer Institut

Swiss Federal Institute of Technology in Zürich (ETH)

D. Pergolesi

Paul Scherrer Institut

Journal of Physical Chemistry C

1932-7447 (ISSN) 1932-7455 (eISSN)

Vol. 121 40 21797-21805

Mechanistic aspects of local structure and proton dynamics in proton conducting oxides for clean energy applications

Swedish Research Council (VR), 2012-01-01 -- 2014-12-31.

New insights in hydrogenous materials for energy

Swedish Research Council (VR), 2011-01-01 -- 2016-12-31.

Swedish Research Council (VR), 2011-01-01 -- 2016-12-31.

Subject Categories

Condensed Matter Physics

DOI

10.1021/acs.jpcc.7b02497

More information

Latest update

6/15/2018