Miscibility gap in CeO2-ZrO2-YO1.5 system as an electrode of solid oxide fuel cell

To detect miscibility gap in [(CeO2)(x)(ZrO2)(1-x)](0.8)(YO1.5)(0.2) (x = 0 -1), powders prepared by liquid-mixing method were investigated by conventi onal X-ray diffraction (NXRD) and Synchrotron X-ray diffraction (SXRD). The NXRD pattern of the samples, calcined at 873 K, exhibited a broadened cubi c structure without any secondary phases. The lattice constants or samples annealed at different temperatures were determined, and they show linear de pendence on cerium content (x) except for 1273 K, which indicates that a co mplete solid solution can be obtained above 1473 K. The NXRD results on sam ples annealed at 1273 K exhibit deviation from Vegard's law. The SXRD patte rns confirmed the existence of miscibility gap in the samples of x = 0.5-0. 8 annealed at T = 1273 K for 778 h. (C) 2001 Elsevier Science B.V. All righ ts reserved.