Preparation of Yttria-Stabilized Zirconia by the Reverse Microemulsion Method and the Effect of Sc and Ce Doping on Microstructure and Ionic Conductivity for Solid Oxide Fuel Cell Applications


Oksuzomer F., Vatansever S., Koc S. N., Deligoz H., Gurkaynak M. A., Somer M.

INTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY, vol.8, no.1, pp.42-48, 2011 (SCI-Expanded) identifier identifier

Abstract

In this study, 8 mol% yttria-stabilized zirconia (8YSZ), ceria-, and scandia-doped YSZ powders were synthesized by the reverse microemulsion method. The powders were calcined at 1000 degrees C and sintered at 1450 degrees C. The crystalline properties and microstructure of the samples were characterized by X-ray diffraction and SEM methods, respectively. Oxygen ionic conductivities of the samples were measured by electrochemical impedance spectroscopy in the temperature range 250-375 degrees C. Grain interior and grain boundary resistivities were also calculated. Particle sizes of YSZ and Sc-doped YSZ were found to be < 100 nm, while that of Ce-doped YSZ was 120-150 nm. Approximately 1 mu m grains were observed after sintering of YSZ at 1450 degrees C. Particularly, the grain boundary and also the grain interior resistivities decreased with 3% scandia-doped YSZ. It was observed that the total conductivity of 3YSZ was higher than that of 3% ceria-doped YSZ.