Microstructural Effects on Disorder and Transport in Irradiated Pyrochlore Thin Films

Complex oxides exhibiting fast ion conduction have surfaced as attractive materials for various applications such as fuel cells, electrolyzers, sensors and gas separation membranes. Literature shows that many of the studies of these materials place emphasis on improving ionic conductivity. Here we focus on improving our understanding of how defects within the microstructure impact ionic transport. We employ irradiation as a tool to induce disorder in oxide materials, then utilize a number of different characterization techniques to determine the relationship between disorder and oxygen ion conduction. In this study, Gd2Ti2O7 (GTO) pyrochlore thin films are prepared on single and polycrystalline Yttria Stabilized Zirconia (YSZ) substrates using RF Magnetron sputtering. Electrochemical Impedance Spectroscopy measurements are performed as a function of temperature in the through-plane configuration using a Cascade Microtech Microprobe Test Station equipped with a Linkam high temperature stage. The EIS data is used to determine the conductivity of GTO films with varying degrees of irradiation induced structural disorder. This work examines how the underlying microstructure in polycrystalline and highly oriented thin films (grown on polycrystalline and single crystal YSZ substrates, respectively) influences irradiation induced disordering and transport properties. Acknowledgements This work was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division.