Layered Perovskites BaM2In2O7 (M = La, Nd): From the Structure to the Ionic (O2−, H+) Conductivity
N. А. Tarasova, А. О. Галишева, И. Е. Анимица, Ksenia G. Belova, Anastasia V. Egorova, E. Abakumova, Dmitry A. Medvedev
Abstract
The design of new oxide compounds that can be used as oxygen- or proton-conducting electrolytes for solid oxide fuel cells is actively in progress. Despite the intensive research activities regarding electrolytes with perovskite/fluorite structures, the search for other structural alternatives is of paramount importance. In this study we focus on a novel material with significantly improved properties for the electrochemical purposes. The two-layered BaNd2In2O7 perovskite with a Ruddlesden–Popper structure was investigated as a protonic conductor for the first time. In detail, its local structure, water uptake, and the ionic (O2−, H+) conductivity were comprehensively studied. The nature of rare-earth elements (M = La, Nd) in the structure of BaM2In2O7 on the structural and transport properties was revealed. The presented analysis showed that the composition of BaNd2In2O7 is nearly pure proton conductor below 350 °C. This work opens up a new way in the design of protonic conductors with double-layered perovskite structure.