LAUSR

Charge transport across and along grain boundaries can have profound implications on the macroscopic behavior of materials used in solid oxide fuel cells, batteries as well as other energy technologies. The grain boundary may serve as high conductivity pathway or roadblock for ionic or electronic carriers. Even pristine grain boundaries, free of impurity species or secondary phases, can display modified transport properties relative to the bulk as a result of space charge effects. This is particularly true of doped ceria, which is a leading candidate for a range of applications due to fast oxygen ion conduction in the bulk. To date, the vast majority of grain boundary studies have relied on macroscopic measurements that yield ensemble averages [1]. However, a fundamental understanding of their behavior requires access to the properties of individual grain boundaries, in terms of both chemistry and electrical profiles. Electron holography offers an excellent combination of high spatial resolution and sensitivity to measure mean inner potential as well as grain boundary potential in these materials.