Structural characterization, stability and electrical properties of strontium niobate ceramic

The double perovskite oxide Sr2CrNbO6 has a cubic structure according to powder X-ray diffraction. After reducing in CO, Sr2CrNbO6 still exhibited a cubic structure refined by Rietveld technique. The TG analysis indicated that Sr2CrNbO6 loses 0.127 oxygen per formula unit from 400 to 700 °C in H2. The morphology and compositions of this ceramic did not significantly change on reduction. The conductivities in various atmospheres were varied from 0.015 to 0.039 S cm−1 at 800 °C. The conductivity exhibits a small oxygen partial pressure dependence in oxygen partial pressure range of 1–10−16 atm, and this may be interpreted to reflect slow equilibration kinetics with decreasing oxygen activity.