Effect of Li2O content and sintering temperature on the grain growth and electrical properties of Gd-doped CeO2 ceramics

The sintering behavior and electrical properties of Gd-doped CeO2 (GDC), with and without Li2O as a sintering additive, were examined. With increasing Li2O content, the grain growth of GDC was enhanced because of an increase in the duration for which a Li-rich liquid phase existed during sintering. The migration of Li ions led to an increase in the electrical conductivity of the Li-doped GDC. When the Li-doped GDC was sintered at a high temperature of 1400 °C, the Li evaporated, resulting in a decrease in the electrical conductivity.