Surface composition of perovskite-type materials studied by Low Energy Ion Scattering (LEIS)

The analysis of the surface chemistry of electrode materials for solid oxide electrochemical conversion devices is of great importance to understand the fundamental mechanism of the oxygen exchange reaction, and the influence of changes in surface chemistry on device degradation. Low Energy Ion Scattering (LEIS) is an extremely surface sensitive analysis technique, capable of probing this chemistry in the very outer atomic layer of a material under conditions relevant to its operational state. In this contribution, we use LEIS to study the Sr segregation process in the perovskite La0.6Sr0.4Co0.2Fe0.8O3 − δ (LSCF), and show that, conversely, there is no segregation of either lanthanide cation in Ruddlesden–Popper structured Pr1La1NiO4 + δ (PLNO).