Crystal structure, hydration, and two-fold/single-fold diffusion kinetics in proton-conducting Ba0.9La0.1Zr0.25Sn0.25In0.5O3−a oxide

Abstract

In this work, hydration kinetics related to the incorporation of water into proton-conducting Ba0.9 La0.1 Zr0.25 Sn0.25 In0.5 O3−a perovskite-type oxide are presented, with a recorded transition on temperature from a single-fold to a two-fold behavior. This can be correlated with an appearance of the electronic hole component of the conductivity at high temperatures. The collected electrical conductivity relaxation data allowed to calculate chemical diffusion coefficient D and surface exchange reaction coefficient k, as well as respective activation energies of their changes on temperature. Presented results are supplemented with a systematic characterization of the structural properties of materials synthesized at different temperatures, amount of incorporated water after hydration in different conditions, influence of water content on the crystal structure, as well as electrical conductivity in dry, H2 O- and D2 O-containing air, which enabled to evaluate proton (deuterium) conductivity.