Synthesis and study of doped SrCeO3 perovskites as a candidate for the electrolyte of Solid Oxide Fuel Cells (SOFC)
摘要
The solid-state reaction method and the glycine nitrate combustion process were used to synthesize the Eu3+ doped strontium cerate. The structural characterization of the prepared crystal powders shows that the solid-state reaction method gives monophasic samples formed of orthorhombic strontium cerate, however, the powders produced by the glycine nitrate process method were essentially formed of orthorhombic strontium cerate with orthorhombic strontium carbonate and cubic cerium dioxide cubic, as impurities. The luminescence analysis of the doped perovskite confirmed that the added Eu3+ ions occupy a unique 4b, non-centrosymmetric Wyckoff position, after substituting Ce4+, in the perovskite orthorhombic structure. Electrical characterization, using complex impedance spectroscopy, in the temperature range between 540 and 660oC, reveals that the doping ratio and the synthesis methos impact, significantly, the conduction and dielectric characteristics of the prepared samples. Therefore, the sample prepared using the solid-state reaction method with the highest Eu3+ doping ratio (8%), shows the best results. The measured total conductivity can reach a value of 0.030 Ω−1cm−1 at 660oC, and the activation energy is about 0.552 eV. The dielectric study confirms the aptitude of the produced samples for use as high-temperature semiconductors.