SAMARIUM DOPED CERIA (Sm_(0.3)Ce_(0.7)O_(1.85)) SYNTHESIS BY GLYCINE NITRATE COMBUSTION METHOD AND ITS APPLICATION AS ELECTROLYTE IN INTERMEDIATE TEMPERATURE SOLID OXIDE FUEL CELL (ITSOFC)

摘要

Samarium doped ceria is well known for its application as an electrolyte in solid oxide fuel cells due to its higher conductivity in the temperature range 600℃-800℃ compared to Yttrium doped Zirconia in the same operating temperature range. This paper is focused on the synthesis of nanocrystalline Samarium doped ceria (Sm_(0.3)Ce_(0.7)O_(1.85)) by Glycine nitrate precursor method to study its ionic conducting properties in intermediate range of operating temperature of a solid oxide fuel cell. Particle size in the range of 10nm to 80nm is obtained by using stoichiometric molar proportion of metal nitrates to fuel which is calculated as 1.7Mole of Glycine. Synthesized SDC nanopowder is characterized by X-ray diffraction, Scanning electron microscopy and EDAX for phase conformation and microstructure and composition studies. Ionic conductivity is measured by impedance analysis in temperature range of 600℃ to 800℃. Ionic conductivity at 800℃ is determined to be 0.002S/cm. Finally, activation energy calculated for both AC and DC conductivity is 0.589eV and 0.688eV respectively.