Ceria-based gas sensors

The electrical conductivity of PrxCe1–xO2–δ (PCO) with x⩽0.05 was examined as functions of praseodymium content (x), oxygen partial pressure and temperature and a defect model based on multiple oxidation states of Pr was found to be consistent with the data. These results are used to examine PCOs potential as an active film in gravimetric sensors.