Todd S. Stefanik

Ceria-based gas sensors

Abstract The electrical conductivity of Pr x Ce 1– x O 2– 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.

Electrical Conductivity in Praseodymium-Cerium Oxide

The electrical conductivity of Pr x Ce 1-x O 2-δ (PCO) for 0 ≤ × ≤ 0.20 was examined over a wide range of temperatures and oxygen partial pressures. A defect model based on multiple Pr valence states was found to be qualitatively consistent with the observed data. A unique pO 2 -dependent ionic conductivity is observed at high pO 2 values in compositions containing low levels of Pr (0 ≤ × ≤ 0.01). In compositions containing higher amounts of Pr (0.05 ≤ × ≤ 0.20), formation of a Pr induced impurity band results in a significant electronic conductivity at high pO 2 values.