Incorporation and Conduction of Protons in Ca, Sr, Ba-Doped BaLaInO4 with Ruddlesden-Popper Structure

The new phases BaLa0.9M0.1InO3.95 (M = Ca2+, Sr2+, Ba2+) with a Ruddlesden-Popper structure were obtained. It was established that all investigated samples were capable for the water uptake from the gas phase. The ability of water incorporation was due to not only by the presence of oxygen vacancies, but also due to the presence of La-O blocks in the structure. The degree of hydration of the samples was much higher than the concentration of oxygen vacancies and the composition of the samples appear to be BaLaInO3.42(OH)1.16, BaLa0.9Ca0.1InO3.25(OH)1.4, BaLa0.9Sr0.1InO3.03(OH)1.84, BaLa0.9Ba0.1InO2.9(OH)2.1. The degree of hydration increased with an increase in the size of the dopant, i.e., with an increase in the size of the salt blocks. It was proven that doping led to the increase in the oxygen ionic conductivity. The conductivities for doped samples BaLa0.9M0.1InO3.95 were higher than for undoped composition BaLaInO4 at ~1.5 order of magnitude. The increase in the conductivity was mainly attributed to the increase of the carrier concentration as a result of the formation of oxygen vacancies during doping. The proton conductivities of doped samples increased in the order Ca2+–Sr2+–Ba2+ due to an increase in the concentration of protons. It was established that all doped samples demonstrated the dominant proton transport below 450 °C.

A highly conductive electrolyte for molten oxide fuel cells

A gas-tight and ductile solid/liquid δ-Bi2O3–0.2 wt% B2O3 electrolyte with the highest oxygen ionic conductivity is developed for molten oxide fuel cells (MOFCs).

Enhanced ionic conductivity in electroceramics by nanoscale enrichment of grain boundaries with high solute concentration

The enhancement of grain boundary oxygen ionic conductivity by four orders of magnitude in an electroceramic is explicitly shown to result from modulation of local grain boundary composition at the atomic level.