Microstructure and electrochemical properties of cathode materials for SOFCs prepared via pulsed laser deposition

Dense La0.8Sr0.2MnO3 (LSM) and La0.5Sr0.5CoO3 (LSC) films were fabricated via pulsed laser deposition (PLD) on different substrates. The crystal structures of the films were characterized via in situ X-ray diffraction and the in-plane electrical properties by impedance spectroscopy from room temperature to 700 °C. While the ablated films appeared to grow in the perovskite phase with the appropriate electrical properties when the substrate temperature was greater than 500 °C, they were amorphous when the substrate temperature was relatively low. Subsequent annealing of amorphous LSM and LSC films in air induced a rapid phase transformation to the perovskite phase. On silicon substrates, this phase transformation occurred at 450 and 600 °C, respectively.