Abstract
Dense LSCF thin films having controlled surfaces were epitaxially grown using pulsed laser deposition (PLD) on gadolinia-doped ceria (GDC) films with (100), (110), and (111) orientations, and then subjected to long-term annealing at 800°C and 900°C in air for 1-3 months. Detailed microstructural characterizations revealed preferential surface segregation for LSCF thin films which were epitaxially grown on (110) and (111)-oriented GDC films whereas this appears mostly inhibited for LSCF thin films on (100)-oriented GDC. Compositional and structural analyses revealed that the surface-segregated crystallites are SrSO4 in origin, which is attributed to the reaction of the segregated Sr cations from LSCF with SO2 present in the air. Furthermore, SrSO4 formation on LSCF surfaces was accompanied by coarsening and granularization of the LSCF layer. These results have implications toward tailoring the performance of cathode surfaces by understanding the dependence of cation segregation on driving forces such as surface chemistry and microstructure.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call