Atomic Scale Picture of the Ion Conduction Mechanism in Tetrahedral Network of Lanthanum Barium Gallate

Journal Article · Tue Jan 01 00:00:00 EST 2013 · Chemistry of Materials

DOI:https://doi.org/10.1021/cm400452n· OSTI ID:1120450

Jalarvo, Niina H ^[1]; Gourdon, Olivier ^[1]; Bi, Zhonghe ^[1]; Gout, Delphine J ^[1]; Ohl, Michael E ^[1]; Paranthaman, Mariappan Parans ^[1]

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1. ORNL

Combined experimental study of impedance spectroscopy, neutron powder diffraction and quasielastic neutron scattering was performed to shed light into the atomic scale ion migration processes in proton and oxide ion conductor; La0.8Ba1.2GaO3.9 . This material consist of tetrahedral GaO4 units, which are rather flexible and rocking motion of these units promotes the ionic migration process. The oxide ion (vacancy) conduction takes place on channels along c axis, involving a single elementary step, which occurs between adjacent tetrahedron (inter-tetrahedron jump). The proton conduction mechanism consists of intra-tetrahedron and inter-tetrahedron elementary processes. The intra-tetrahedron proton transport is the rate-limiting process, with activation energy of 0.44 eV. The rocking motion of the GaO4 tetrahedron aids the inter-tetrahedral proton transport, which has the activation energy of 0.068 eV.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 1120450
• Journal Information: Chemistry of Materials, Vol. 25, Issue 6; ISSN 0897--4756
• Country of Publication: United States
• Language: English