Role of the doping level in localized proton motions in acceptor-doped barium zirconate proton conductors
Artikel i vetenskaplig tidskrift, 2018

Acceptor-doped barium zirconates are currently receiving considerable interest because of their high proton conductivity at intermediate temperatures, making them applicable as electrolytes in various electrochemical devices, but the mechanism of proton conduction is unclear. Here, we investigate the role of the acceptor-dopant level in the localized proton motions, i.e. proton transfers between oxygens and O-H reorientations, in hydrated samples of the proton conducting, acceptor-doped, perovskites BaZr1-xInxO3-x/2 with x = 0.10 and 0.20, using quasielastic neutron scattering (QENS). Analysis of the QENS spectra reveals that several proton transfer and O-H reorientational motions contribute to the QENS signal, as a consequence of the locally disordered nature of the structure due to the In doping of these materials, and establishes a generic and complex picture of localized proton dynamics in acceptor-doped barium zirconate based proton conductors. A comparison of the QENS results with vibrational spectroscopy data of the same materials, as reported in the literature, suggests a predominance of O-H reorientational motions in the observed dynamics. The highest doping level corresponds to a more distorted structure and faster dynamics, which thus indicates that some degree of structural disorder is favourable for high local proton mobility.

Författare

Daria Noferini

Chalmers, Kemi och kemiteknik

Institut Laue-Langevin

Michael Marek Koza

Institut Laue-Langevin

Habibur Seikh Mohammad Rahman

Chalmers, Kemi och kemiteknik, Energi och material, Oorganisk miljökemi

Zach Evenson

Technische Universität München

Heinz Maier-Leibnitz Zentrum (MLZ)

Gøran J. Nilsen

ISIS Neutron and Muon Source

Institut Laue-Langevin

Sten Eriksson

Oorganisk miljökemi 2

Andrew Wildes

Institut Laue-Langevin

Maths Karlsson

Oorganisk miljökemi 2

Physical Chemistry Chemical Physics

1463-9076 (ISSN) 1463-9084 (eISSN)

Vol. 20 13697-13704

Ämneskategorier

Fysikalisk kemi

Fysik

Kemi

DOI

10.1039/C7CP07340B