The structure-property relationship between atomic cation substitution and bulk scale conductivity in perovskites has been studied systematically. A series of Na-Nb perovskites has been synthesized via two methods (1) ion-exchange or (2) synthetic metal doping of microporous Sandia Octahedral Molecular Sieve (SOMS, Na4Nb4-2xM2xO12-x H2O, where 0 = x = 0.4) phases, followed by calcination to the perovskite phase. We show that the oxygen conductivity can be altered by substitution of the A- and B- site cations in the perovskite structure (NaNb1-2xM2xO3-x, where 0 = x = 0.1). Furthermore, we are able to show improved of ion conductivity over YSZ with the Na0.9Mg0.1Nb0.8Ti0.2O3-y phase with our highest conductivity observed (0.176 S/cm) at 1173 K. These fundamental studies allow us to develop perovskites with optimal electric properties.
Citation: Chemistry of Materials
Pub Type: Journals
ionic conductivity, perovskites, SOMS