Electrodes for oxygen sensors based on r

Rare earth manganites and cobaltites are particularly suitable electrode materials for solid electrolyte oxygen sensors. The objective of this study was to investigate the preparation and characterization of perovskite-type manganites (Ln, _,Ca(Sr), MnO) and cobaltites (Ln , _,ySr,CoO) for enhanced performance in oxygen sensing applications. Using a systematic methodology, these materials were synthesized by sintering at temperatures ranging from 1270 K to 1570 K in air, and their phase formation was confirmed through X-ray powder diffraction. The cation concentrations were assessed via atom absorption spectroscopy, and isothermal oxygen permeation measurements were conducted with specialized zirconia solid electrolyte tubes. Furthermore, ultraviolet photoemission spectroscopy (UPS) was utilized to analyze the work function of electrons, the positioning of the Fermi level in relation to the valence band edge, and variations in the ionization potential across temperatures. Results indicated that the polarization resistivity of the perovskite-type oxide electrodes was determined from steady-state current density overpotential curves measured in a three-electrode system. Overall, the findings provide important insights into the effectiveness of these materials for high-temperature sensor applications.