Effects of CoO doping on sintering and electrical conductivity of Ce0.8Gd0.2O1.9 prepared using CeO2 powder and Gd precipitation

Abstract

This paper reports on the preparation of a fully dense Gd-doped CeO2 (GDC) at low sintering temperature using CeO2 powder and Gd precipitation in the presence of CoO as a sintering aid. A mixture of CeO2 powder and Gd precipitates was calcined at 700 degrees C followed by milling that resulted in the GDC (Ce0.8Gd0.2O1.9) powder with an average particle size of 0.46 mu m. Sintering of the undoped sample showed a relative density of 99.2% at 1500 degrees C, whereas the samples doped with 3 mol% and 5 mol% CoO exhibited a significant densification at the lower temperature reaching a relative density of 98.8% at 1200 degrees C. The electrical conductivities of both doped samples were almost identical but higher than those of the undoped sample at all measuring temperatures.