Novel Nb5+-doped hexagonal perovskite Ba5In2Al2ZrO13 (structure, hydration, electrical conductivity)

Abstract

A new phase Ba5In2Al2Zr0.9Nb0.1O13.05 with a hexagonal perovskite structure was obtained. The substitution of Zr4+ by smaller Nb5+ was accompanied by the incorporation of the oxygen interstitials and did not lead to a significant change in the lattice parameters. It was established that the investigated sample was capable of water incorporation from the gas phase; the hydration degree value was 0.24 mol H2O. IR-spectroscopy analysis revealed the presence of OH−-groups with different thermal stability, which participate in different hydrogen bonds. The new phase Ba5In2Al2Zr0.9Nb0.1O13.05 demonstrates the predominant protonic conductivity at pH2O = 2·10−2 atm and Т < 600 °C.