Oxide ionic conductivity in Pr₂(Ni, Cu, Ga)O _{4 + δ}-(Ce, Sm)O_2-δ laminated film estimated with the Hebb-Wagner method

Oxide ionic conductivity in multilayer nano-thickness film consisting of Cu- and Ga-doped Pr₂NiO_{4 + δ} (PNCG) and Sm-doped CeO₂ (SDC) was measured using an ion blocking technique. It was found that oxide ionic conductivity in laminated films along the in-plane direction was higher than that of the SDC bulk, and that electronic hole conductivity was suppressed compared with the PNCG bulk. The estimated activation energy for oxide ionic conductivity in the PNCG/SDC multilayer film was 0.52 eV, a value that is much smaller than those in conventional oxide ionic conductors such as yttria-doped zirconia. The transport number of oxide ionic conductivity (t _i, P_O2 = 0.21) was 0.99 to 0.61 at a temperature region from 1073 K to 673 K, suggesting that the main carriers in the PNCG/SDC laminated film were oxide ions.