Local structure and vibrational dynamics in indium-doped barium zirconate
Artikel i vetenskaplig tidskrift, 2019

Barium zirconate (BaZrO3), when substituted with trivalent acceptor ions to replace Zr4+, is a proton conducting material of interest for several electrochemical applications. The local coordination environments, and vibrational dynamics, of the protons are known to critically influence the material's proton conducting properties, however, the nature of the static and dynamic structure around the protons and, especially, how it is affected by the dopant atoms for high doping concentrations, remains to be elucidated. Here we report results from X-ray powder diffraction, infrared (IR) spectroscopy, inelastic neutron scattering (INS) and ab initio molecular dynamics (AIMD) simulations on a hydrated sample of BaZrO3 substituted with 50% In3+. The investigation of the momentum-transfer (Q) dependence of the INS spectrum is used to aid the analysis of the spectra and the assignment of the spectral components to fundamental O-H bend and O-H stretch modes and higher-order transitions. The AIMD simulations show that the INS spectrum is constituted of the overlapping spectra of protons in several different local structural environments, whereas the local proton environments for specific protons are found to vary with time as a result of thermally activated vibrations of the perovskite lattice. It is argued that, converse to more weakly doped systems, such as 20% Y-doped BaZrO3, the dopant-proton association effect does not hinder the diffusion of protons due to the presence of percolation paths of dopant atoms throughout the perovskite lattice.

Författare

Laura Mazzei

Chalmers, Fysik, Kondenserade materiens fysik

Adrien Perrichon

Chalmers, Kemi och kemiteknik, Energi och material, Oorganisk miljökemi 2

Alessandro Mancini

Universita degli studi di Pavia

Göran Wahnström

Chalmers, Fysik, Material- och ytteori

Lorenzo Malavasi

Universita degli studi di Pavia

Stewart F. Parker

ISIS Facility

Lars Börjesson

Chalmers, Fysik, Kondenserade materiens fysik

Maths Karlsson

Chalmers, Kemi och kemiteknik, Energi och material, Oorganisk miljökemi 2

Journal of Materials Chemistry A

20507488 (ISSN) 20507496 (eISSN)

Vol. 7 13 7360-7372

Mekanistiska aspekter av lokal struktur och protondynamik i protonledande oxider för rena energiapplikationer

Vetenskapsrådet (VR), 2012-01-01 -- 2014-12-31.

Mekanistiska aspekter om protoner i rena energimaterial

Stiftelsen för Strategisk forskning (SSF), 2012-04-01 -- 2016-03-31.

Ny förståelse om väteinnehållande material för energi

Vetenskapsrådet (VR), 2011-01-01 -- 2016-12-31.

Vetenskapsrådet (VR), 2011-01-01 -- 2016-12-31.

Ämneskategorier

Fysikalisk kemi

Materialkemi

Biomaterialvetenskap

DOI

10.1039/c8ta06202a

Mer information

Senast uppdaterat

2019-08-08