Effect of Er, Gd, and Nd Co-Dopants on the Properties of Sm-Doped Ceria Electrolyte for IT-SOFC

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Arabaci A.

METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE, sa.5, ss.2282-2288, 2017 (SCI-Expanded, Scopus) identifier identifier

Özet

Doped ceria electrolytes of Ce0.8Sm0.20O1.90 (SDC), Ce0.8Er0.08Sm0.12O1.90 (ESDC), Ce0.8Gd0.08Sm0.12O1.90 (GSDC), and Ce0.8Nd0.08Sm0.12O1.90 (NSDC) were prepared by a citric-nitrate combustion process. The thermal decomposition of the precursor was investigated by simultaneous thermogravimetric analysis and differential thermal analysis experiments. The phase structure of the calcined and sintered powders was characterized by X-ray diffraction analysis. All of the samples were fluorite-type ceria-based solid solutions. The calcined and sintered powders were also characterized by Fourier transform infrared spectroscopy. Scanning electron microscopy was used to characterize the samples after calcination and sintering. A relative density over 95 percent of the theoretical density was achieved after the sintering process. Electrical conductivities of the sintered samples were measured using the impedance spectra method. The highest ionic conductivity value was found to be 5.28 x 10(-2) S cm(-1) at 1023 K (750 A degrees C) for GSDC sintered at 1673 K (1400 A degrees C) for 6 hours.

Doped ceria electrolytes of Ce0.8Sm0.20O1.90 (SDC), Ce0.8Er0.08Sm0.12O1.90 (ESDC),
Ce0.8Gd0.08Sm0.12O1.90 (GSDC), and Ce0.8Nd0.08Sm0.12O1.90 (NSDC) were prepared by a
citric–nitrate combustion process. The thermal decomposition of the precursor was investigated
by simultaneous thermogravimetric analysis and differential thermal analysis experiments. The
phase structure of the calcined and sintered powders was characterized by X-ray diffraction
analysis. All of the samples were fluorite-type ceria-based solid solutions. The calcined and
sintered powders were also characterized by Fourier transform infrared spectroscopy. Scanning
electron microscopy was used to characterize the samples after calcination and sintering. A
relative density over 95 percent of the theoretical density was achieved after the sintering
process. Electrical conductivities of the sintered samples were measured using the impedance
spectra method. The highest ionic conductivity value was found to be 5.28 9 102 S cm1 at
1023 K (750 C) for GSDC sintered at 1673 K (1400 C) for 6 hours.