Oxide ion conductivity in doped NdBaInO₄

Oxide ion conductivity in doped NdBaInO₄ with new type oxygen deficient perovskite was studied and it was found that doping Ti to In site is effective for increasing the oxide ion conductivity. Since increasing amount of doped Ti increased the partial electronic conductivity under reducing atmosphere, the optimized amount of Ti doped for In site exists around 20 mol%, namely, NdBaIn_0.8Ti_0.2O₄. The estimated transport number of oxide ion in this optimized composition was higher than 0.8 from H₂-O₂ oxygen concentration cell, however, it is lower than 0.1 from N₂-O₂ cell because the hole conduction is dominant in high P_O2 range. Consequently, although the oxide ion conductivity is around log(σ/Scm^{- 1}) = - 2.5 at 1173 K, this study reveals that Ti doped NdBaInO₄ which is unique edge oxygen facing structure, is a new family of oxide ion conductor.