Development of BaZr_(0.80)Y_(0.20)O_3 and SrCe_(0.95)Yb_(0.05)O_3 Heterostructures for Proton-conducting Oxides

摘要

An investigation was carried out on BaZr_(0.80)Y_(0.20)O_3 (BZY) and SrCe_(0.95)Yb_(0.05)O_3 (SCY) heterostructures for proton-conducting oxides. The het-erostructures were produced by a combinatorial approach yielding 27 different phase fractions in a single sputter deposition. The heterostructures with different phase fractions were evaluated by electrochemical impedance spectroscopy and DC 4-probe resistivity measurement to identify promising compositions for proton-conducting oxides. The findings indicated that the higher SCY fraction in heterostructures resulted in higher conductivity under a hydrogen atmosphere. The highest conductivity was measured with BZY6-SCY94 composition, while BZY12-SCY88, BZY18-SCY82, and BZY34-SCY63 exhibited slightly lower conductivities at 500° C. Additionally, it was observed that the heterostructures exhibited different trends as a function of temperature. This indicated that the hetero-interface formed in these oxides does not have a linear impact on the electrochemical performance. Another finding is that the hetero-structured oxides typically exhibited conductivity higher than 10~(-2) S/cm, taken as a critical threshold, at temperatures lower than 500° C. The results indicated that the heterostructures produced with the methodology in the study offer remarkable total conductivities at relatively low operating temperatures.