δ-BiO-based materials have long been a focus of interest as potential solid oxide fuel cell materials due to their high electrical conductivity. Here, extensive studies of thermal stability, polymorphism and conductivity have been carried out for the first time on BiWO ( = La, Pr or Nd) compounds in the ternary BiO-O-WO system, mentioned more than 20 years ago by Watanabe. The obtained single-phase materials were found to be sufficiently dense (more than 94%) and thermally stable (up to 900 °C).
View Article and Find Full Text PDFThe conductive properties of fluorite-like structures KLnMoOF (Ln = La, Pr, Nd: KLM, KPM, KNM) have been studied theoretically and experimentally. Theoretical studies included the geometrical-topological analysis of voids and channels available for migration of working ions; bond valence site energy calculations of the oxygen ions' migration energy; quantum-chemical calculations for the estimation of the oxygen vacancies formation energy. Experimental measurements of conductivity were made using impedance spectroscopy and as a function of oxygen partial pressure.
View Article and Find Full Text PDF