Microstructures and oxygen diffusion at the LaMnO3 film/yttria-stabilized zirconia interface

Microstructures and oxygen diffusion were investigated at the LaMnO3 film/Y2O3-stabilized ZrO2 (YSZ) interface by transmission electron microscopy (TEM), atomic force microscopy (AFM) and secondary ion mass spectrometry (SIMS) analysis for samples after heat treatments and isotope oxygen exchange (16O/18O exchange) experiments. In “as-deposited LaMnO3 film” on YSZ, the 18O-diffusion profile showed a significant decrease in 18O concentration near the LaMnO3 film/YSZ interface, which corresponds to an amorphous layer. The heat treatment diminished the amorphous layer at the LaMnO3 film/YSZ interface. In the heat-treated sample (1473 K for 5 h), the 18O-diffusion profile in the LaMnO3 film showed gradual decrease and a subsequent minimum of the 18O concentration at the LaMnO3/YSZ interface. This is due to the grain growth of lanthanum manganite, which provides the shorter paths to YSZ.