Effect of harsh anneals on the LSM/YSZ interfacial impedance profile

AC impedance spectroscopy was used to investigate the effects of microstructural and interfacial changes on the cathodic reaction occurring at the LSM/YSZ interface. These effects were induced by using harsh anneals of temperatures ranging from 1250 to 1400 °C and times ranging from 1 to 48 h. Additional characterization of the effects of the anneal was performed through the use of SEM and EDS. A separate semicircle with a distinct time constant was observed in the Nyquist plot of samples that have been exposed to anneals of 1400 °C. The magnitude of the resistance of this semicircle was shown to be dependent on the time and temperature of the applied anneal. Extended interfacial pores were also shown to occur in 1400 °C annealed samples.