BaSnO/sub 3/ oxygen sensors without the need of a reference electrode

A new sensor structure, based on a sensing layer formed by a mixed conduction ceramic of BaSnO/sub 3/ playing the role of an active element in a device structure, is proposed for oxygen detection in harsh ambient. I-V curves at different operating temperatures and at different gas atmospheres have been measured. Variation of more than 1 Volt is obtained for a current source of about 60 mA. The device shows a significant sensitivity to oxygen, with a maximum response at 400/spl deg/C. Sensing mechanisms are discussed and a model describing the behaviour of the structure is proposed. It takes into account the different types of conduction of the BaSnO/sub 3/ as the temperature is modified.