Enhancing ionic conductivity through reduction of grain boundary segregation in Gd doped ceria by cold sintering

This study investigates the effect of cold sintering process on the ionic conductivity of gadolinium-doped ceria (GDC). After cold sintering at 350 degrees C, the final sintering temperature could be reduced to 950 degrees C, achieving a similar density to conventionally sintered GDC at 1350 degrees C but with smaller grain sizes. Despite the increased grain boundary area, cold-sintered GDC showed improved ionic conductivity, attributed to the suppression of Gd segregation and the formation of thinner grain boundaries. The findings highlight that cold sintering not only refines the microstructure but also modifies grain boundary chemistry for enhanced ionic transport. These findings open new avenues for the fabrication of materials that require both structural robustness and improved ionic transport properties.