Details

Autor(en) / Beteiligte

• Mazzei, Laura
• Piccinelli, Fabio
• Bettinelli, Marco
• Parker, Stewart F.
• Karlsson, Maths

Titel

The effect of cation substitution on the local coordination of protons in Ba2In1.85M0.15O6H2 (M = In, Ga, Sc and Y)

Ist Teil von

• Solid state ionics, 2021-07, Vol.365, p.115624, Article 115624

Ort / Verlag

Amsterdam: Elsevier B.V

Erscheinungsjahr

2021

Link zum Volltext

Quelle

Elsevier ScienceDirect Journals Complete

Beschreibungen/Notizen

• We report on an investigation of the local structure and vibrational dynamics in the brownmillerite-based proton conductors Ba2In1.85M0.15O6H2 with M = In, Ga, Sc and Y. The aim is to determine the effect of the cation (M) substitution on the local coordination environment of the protons. The techniques used are infrared spectroscopy and inelastic neutron scattering. The materials are characterized by two main types of proton sites, denoted as H(1) and H(2), which are featured by different local structures. We establish that the relative population of these two proton sites varies as a function of M. Specifically, it is found that, with respect to Ba2In2O6H2, the relative population of H(1) protons increases upon the substitution of In with any of the three different cations. The strongest effect is observed for M = Ga and Sc, whereas the effect observed for M = Y is minor. This new insight motivates efforts to unravel the mobility of the two types of protons, since then cation modification would offer a rational route for improving the proton conductivity of these types of materials. •Cation (Ga, Sc and Y) substitution for In in Ba2In2O5H2 has significant effects on local structure and dynamics.•Cation substituted materials are isostructural to Ba2In2O5H2.•Cation substitution for In in Ba2In2O5H2 controls the population of various proton sites•With respect to Ba2In2O5H2, the population of protons sites characterized by highly-distorted proton environments is lower in cation substituted materials.•The effect of cation substitution on local structure and dynamics is the largest for Sc substitution and the smallest for Y substitution.