EIS measurements at different pO2 and DRT analysis for partially amorphous LSC

Measurements were conducted at varying oxygen partial pressures (pO₂) of 0.5%, 1%, 3%, 5%, 10%, and 20%, with a constant gas flow rate of 50 ml·min⁻¹. Prior to each measurement, the samples were stabilized in the target pO₂ atmosphere for a duration of 4 hours. Electrochemical impedance spectroscopy (EIS) was carried out across a temperature range of 400 °C to 300 °C, with measurements taken at 25 °C intervals. For a more comprehensive interpretation of the impedance spectra, the Distribution of Relaxation Times (DRT) method was employed. The analysis was performed using the DRTtool MATLAB graphical user interface, applying the C4 Matérn discretization scheme, with a second-order regularization derivative and a regularization parameter (λ) set to 10⁻⁴.