A novel sintering method to obtain fully dense gadolinia doped ceria by applying a direct current

► We reported for the first time that GDC electrolyte could be sintered to full dense at an extremely low temperature under an applied DC electric field. ► At the same time, we show that the grain size of sintered GDC electrolyte decreased with the increase of the applied field. ► This new approach will greatly change the manufacturing approach of SOFCs and will indicate a feasible way for the building of Nano orderly anode support SOFCs. ► Besides, it will improve the ionic conductivity and the mechanical properties of GDC electrolyte. ► These results may also have general implication in lowering the temperature of SOFCs. A fully dense Ce0.8Gd0.2O1.9 (gadolinia doped ceria, GDC) is obtained by a novel using a sintering technique for several seconds at 545°C by applying a direct current (DC) electrical field of 70Vcm−1. The onset applied field value of this phenomenon is 20Vcm−1, and the volume specific power dissipation for the onset of flash sintering is about ∼10mWmm−3. Through contrast with the shrinkage strain of the conventional sintering as well as scanning electron microscopy (SEM) analysis, we conclude that GDC specimens are sintered to fully density under various applied fields. In addition, we demonstrate that the grain size of GDC is decreasing with the increase of applied field and the decrease of sintering temperature. Through calculation, we find that sintering of GDC can be explained by the Joule heating from the applied electrical field.