Impedancemetric YSZ-based oxygen sensor using BaFeO3 sensing-electrode

This paper deals with an impedancemetric sensor based on an yttria-stabilized zirconia (YSZ) using an oxide sensing-electrode (SE) for measuring O2 concentration. Fourteen oxides were examined as the SE materials for selective detection of O2. Among the sensors examined, the YSZ-based sensor using BaFeO3-SE was found to be insensitive to interfering gases such as NH3, H2, C3H6, C3H8, CH4, NO2, NO or CO, while sensitive to only O2 at 600 °C. The impedance value |Z| at 10 Hz for the sensor using BaFeO3-SE decreased linearly with increasing O2 concentration on a logarithmic scale in the range of 0.05–21 vol.%. The present sensor exhibited quick and repeatable responses to the change in O2 concentration.