Synthesis, sintering and conductivity behavior of ceria-doped Scandia-stabilized zirconia

In this work, the effect of ceria addition on the phase formations, sinterability and electrical conductivity of 10 mol.% scandia stabilized zirconia (SSZ) is investigated. Ceria co-doped SSZ (SSZ–xCeO2 (x = 0.5, 1.0, 5.0 mol.%)) powders were successfully synthesized by glycine-nitrate process and the electrical conductivity was measured in the temperature range of 600–900 °C. Fourier-transform infrared spectroscopy (FT-IR) analysis showed that the samples sintered at 1300 °C/3 h are free from impurities such as un-decomposed nitrates, residual water and nitrile intermediates. From the X-ray diffraction (XRD) analysis, the sintered samples results revealed that the presence of cubic and rhombohedral β-phases and Raman spectroscopy analysis further revealed the presence and monoclinic and tetragonal phases. From the linear shrinkage spectra, a linear shrinkage of 27% was observed at 1300 °C for SSZ and was decreased with the increase of cerium oxide content. The electrical conductivity has been decreased with the increase of ceria content and the SSZ–0.5CeO2 sample displayed a higher electrical conductivity compared to others indicating that as small as 0.5 mol.% CeO2 doping in SSZ is enough to ensure good conductivity results for its potential application as an electrolyte material in intermediate-temperature solid oxide fuel cells (IT-SOFCs).