Electrical and oxygen sensing properties of Nd 1−x Ba x CoO 3 ceramics

Nd1−xBaxCoO3 (0 ≤ x ≤ 0.2) ceramics was synthesized by solid state reaction. All the samples have an orthorhombic perovskite structure (Space group P n m a). The electrical transport property indicates that Ba doped NdCoO3 ceramics goes through semiconductor–metal phase transition. The electrical resistivity of Nd1−xBaxCoO3 (0 ≤ x ≤ 0.15) ceramics decreases, while the electrical resistivity of Nd0.8Ba0.2CoO3 ceramics increases with the increase of temperature. The chemical-sensing property shows that Nd1−xBaxCoO3 ceramics is very sensitive to oxygen. Also, increasing Ba2+ doping concentration can reduce the oxygen desorption rate and increase the sensitivity of resistivity. These results indicate that Ba2+ doped NdCoO3 ceramics is not only the good candidate of the cathode materials of solid fuel cells but also the good materials of gas sensor devices.